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Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area i 

Aurecon Project No: 402992 

Water Reconciliation Strategy Study for the Large Bulk 

Water Supply Systems: Greater Bloemfontein Area 

Prepared by: Aurecon (SA) (Pty) Ltd 

Aurecon Centre 

1 Century City Drive 

Waterford Precinct 

Century City 

Cape Town 

7441 

South Africa 

INTERVENTIONS REPORT 

Tel: 021 526 9400 

Fax: 021 526 9500 

FINAL 

June 2012 

Prepared for: Directorate: National Water Resource Planning 

Department of Water Affairs 

Private Bag X313 

Pretoria 

0001 

South Africa 

Tel: 012 336 7500 

Fax: 012 324 6592 

Interventions Report June 2012

Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area iii 

This report is to be referred to in bibliographies as: 

Department of Water Affairs, South Africa. 2012. Interventions Report for the Large Bulk Water Supply 

Systems of the Greater Bloemfontein Area. Prepared by Aurecon in association with GHT Consulting 

Scientists and ILISO Consulting as part of the Water Reconciliation Strategy Study for the Large Bulk Water 

Supply Systems: Greater Bloemfontein Area. DWA Report No. P WMA 14/C520/00/0910/03 


Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area iv 

Water Reconciliation Strategy Study for the Large Bulk 

Water Supply Systems: Greater Bloemfontein Area 

Report Name 

Study Reports 

DWA 

Report Number 

Aurecon 

Report Number 

Inception P WMA 14/C520/00/0910/01 402992/6231 

Preliminary Reconciliation Strategy P WMA 14/C520/00/0910/02 402992/6232 

Interventions Report P WMA 14/C520/00/0910/03 402992/6233 

Water Quality Assessment P WMA 14/C520/00/0910/04 402992/6234 

Reconciliation Strategy P WMA 14/C520/00/0910/05 402992/6235 


Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area v 

ACKNOWLEDGEMENTS 

P van Niekerk DWA 

J van Rooyen DWA 

J Rademeyer DWA 

D Ristic DWA 

F Fourie DWA 

J van Wyk DWA 

T Makombe DWA 

T Masike DWA 

P Pyke DWA 

P Herbst DWA 

B Mwaka DWA 

T Ntili DWA 

P Ramunenyiwa DWA 

LR Tloubatla DWA 

AG Visser DWA 

B Malakoane Bloem Water 

MD Kgwale Bloem Water 

M Tuck Bloem Water 

L E van Oudtshoorn Bloem Water 

L Ntoyi Mangaung Municipality 

M Tsomela Mangaung Municipality 

K Mokhoabane Mangaung Municipality 

G Fritz Mangaung Municipality 

N Knoetze Orange-Riet WUA and Lower Modder WUA 

C Wessels Kalkveld WUA 

Mr Moshounyane Department of Rural Development and Land Reform 

R Jacobs Free State Agriculture 

H Grobler Free State Agriculture 


Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area vi 

TABLE OF CONTENTS 

Page No 

1. BACKGROUND ..................................................................................................... 1 

1.1 SCOPE OF THE PROJECT .......................................................................................................... 1 

1.2 STUDY AREA ................................................................................................................................ 1 

2. CURRENT INFRASTRUCTURE ............................................................................ 3 

2.1 THE GREATER BLOEMFONTEIN AREA WATER SUPPLY SYSTEM ......................................... 3 

2.1.1 The Caledon – Bloemfontein Transfer ............................................................................ 3 

2.1.2 The Maselspoort Scheme ............................................................................................... 3 

2.1.3 The Novo Transfer Scheme ............................................................................................ 5 

2.2 POTABLE WATER BULK INFRASTRUCTURE ............................................................................ 5 

2.3 MAJOR WASTEWATER TREATMENT WORKS .......................................................................... 5 

3. AVAILABLE SUPPLY ............................................................................................ 6 

3.1 SURFACE WATER ........................................................................................................................ 6 

3.1.1 Caledon River Sub-catchment ........................................................................................ 6 

3.1.2 Modder River Sub-catchment ......................................................................................... 6 

3.1.3 Riet River Sub-catchment ............................................................................................... 7 

3.1.4 Upper Orange River ....................................................................................................... 7 

3.1.5 Lesotho ........................................................................................................................ 7 

3.2 GROUNDWATER .......................................................................................................................... 7 

3.3 SUMMARY OF WATER RESOURCES SERVING THE GREATER 

BLOEMFONTEIN AREA ................................................................................................................ 7 

4. WATER REQUIREMENTS................................................................................... 10 

4.1 EXISTING REQUIREMENTS ...................................................................................................... 10 

4.1.1 Urban Water Requirements of the Greater Bloemfontein Area ..................................... 10 

4.1.2 Breakdown of Urban Consumption ............................................................................... 12 

4.1.3 Agricultural Water Requirements .................................................................................. 13 

4.2 FUTURE WATER REQUIREMENT ............................................................................................. 15 

4.2.1 Understanding growth in Water Requirements ............................................................. 15 

4.2.2 Population Growth Rates .............................................................................................. 15 

4.2.3 Economic Growth Rates ............................................................................................... 16 

4.2.4 Future Water Requirement Scenarios .......................................................................... 16 

4.2.5 Agricultural Water Requirements .................................................................................. 18 

5. WATER BALANCE .............................................................................................. 19 

5.1 THE ORANGE RIVER SYSTEM ................................................................................................. 19 

5.2 THE GREATER BLOEMFONTEIN AREA ................................................................................... 20 

6. ISSUES WHICH COULD IMPACT ON THE RECONCILIATION OF SUPPLY 

AND REQUIREMENT .......................................................................................... 21 

7. INTERVENTIONS SELECTED FOR PRELIMINARY EVALUATION ................. 22 

7.1 PROCESS ................................................................................................................................... 22 

7.2 OBJECTIVES OF THE PRELIMINARY SCREENING WORKSHOP ........................................... 22 

7.3 SCREENING WORKSHOP STARTER DOCUMENT .................................................................. 22 


Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area vii 

7.4 ATTENDANCE AT WORKSHOP ................................................................................................. 23 

7.5 SELECTION CRITERIA ............................................................................................................... 23 

7.5.1 Methodology ................................................................................................................. 23 

7.5.2 Costing ...................................................................................................................... 24 

7.5.3 Outcomes of Preliminary Screening Workshop ............................................................ 24 

7.5.4 Refinement of Selected Potential Interventions ............................................................ 24 

8. SELECTED POTENTIAL INTERVENTIONS ....................................................... 25 

A1 & A2 EFFICIENT USE OF WATER AND LOSS MANAGEMENT ......................................................... 28 

B1. RANGE OF INTERVENTIONS .................................................................................................... 34 

B2. AGRICULTURAL IRRIGATION AUDIT UPSTREAM OF MASELSPOORT 

WEIR WITH IMPROVEMENT FOR CATCHMENT C52A ............................................................ 38 

C1. UTILISING SURPLUS CAPACITY IN THE ORANGE RIVER BY PUMPING TO 

KNELLPOORT DAM FROM GARIEP DAM ................................................................................. 43 


KNELLPOORT DAM FROM VANDERKLOOF DAM ................................................................... 46 


KNELLPOORT DAM FROM BOSBERG / BOSKRAAI DAM ........................................................ 49 

C4. MODIFICATIONS TO WELBEDACHT DAM: EXTEND SCOUR OPERATIONS & 

LOWER OUTLETS ...................................................................................................................... 53 

C5. MODIFICATIONS TO CALEDON-MODDER SYSTEM ................................................................ 55 

C6. POLIHALI DAM – LESOTHO HIGHLANDS PHASE 2 ................................................................. 61 

D1. PLANNED DIRECT RE-USE – NEW NORTH EASTERN ........................................................... 66 

D2. PLANNED INDIRECT RE-USE - TRANSFER TO 

UPSTREAM OF MOCKES DAM ................................................................................................. 68 

D3. PLANNED INDIRECT RE-USE – KRUGERSDRIFT DAM ........................................................... 70 

D4. PLANNED DIRECT RE-USE – BLOEMSPRUIT .......................................................................... 72 

D5. RE-USE OF TREATED EFFLUENT – DIRECT USE: IRRIGATION ............................................ 74 

E. GROUNDWATER ........................................................................................................................ 77 

E1. IKGOMOTSENG AQUIFER ......................................................................................................... 80 

E2. BLOEMFONTEIN AQUIFER ........................................................................................................ 83 

E3. THABA NCHU AQUIFER ............................................................................................................ 87 

E4, 5, 6, AND 7. TOWN GROUNDWATER INTERVENTIONS ............................................................... 90 

E4. REDDERSBURG TOWN GROUNDWATER INTERVENTIONS .................................................. 91 

E5. EDENBURG TOWN GROUNDWATER INTERVENTIONS ......................................................... 94 

E6. DEWETSDORP TOWN GROUNDWATER INTERVENTIONS .................................................... 97 

E7. WEPENER TOWN GROUNDWATER INTERVENTIONS ......................................................... 100 

E8. GROUNDWATER INTERVENTIONS BASED ON WELLFIELDS NEXT TO / IN THE 

VICINITY OF PIPELINE – DE HOEK RESERVOIR ................................................................... 103 

E9. GROUNDWATER INTERVENTIONS BASED ON WELL FIELDS NEXT TO / IN THE 

VICINITY OF PIPELINE – LIEUKOP OFF-TAKE CHAMBER .................................................... 105 

F. WATER TRADING ..................................................................................................................... 108 

SECTION G ..................................................................................................................... 110 

G1. TUNNEL FROM CALEDON ....................................................................................................... 111 

G2. NEW DAM ON THE CALEDON RIVER ..................................................................................... 112 

G3. TRANSFER OF MINE WATER .................................................................................................. 113 

9. REFERENCES ................................................................................................... 114 


Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area viii 

TABLES 

Table 3.1: Summary of Primary Surface Water Resources ........................................................................ 8 

Table 3.2: Adjustment of the Yield to Incorporate Recent Operating Information and Hydrology ................ 8 

Table 3.3: Factors with Potential to Influence Net System Yields ............................................................... 9 

Table 4.1: Metered Bulk Water Consumption for Towns Supplied with Water from 

the Greater Bloemfontein System (Excluding Groundwater) .................................................... 10 

Table 5.1: Orange River Water Balance ................................................................................................... 19 

FIGURES 

Figure 1.1: Study Area ................................................................................................................................. 2 

Figure 2.1: Greater Bloemfontein Water Supply Scheme ............................................................................ 4 

Figure 4.1: Metered Bulk Water Supplied from the Greater Bloemfontein System ..................................... 11 

Figure 4.2: MMM Water Consumption ....................................................................................................... 12 

Figure 4.3: Current Water Use for Bloemfontein ........................................................................................ 12 

Figure 4.4: Current Water Use for Botshabelo ........................................................................................... 13 

Figure 4.5: Current Water Use for Thaba Nchu ......................................................................................... 13 

Figure 4.6: Registered Water Use and Resource Allocation in the Quaternary Catchments Surrounding 

the Greater Bloemfontein Area ................................................................................................ 14 

Figure 4.7: Water Requirement Scenarios for the Study Area ................................................................... 17 

Figure 5.1: Surface Water Balance for Study Area .................................................................................... 20 

Aurecon electronic file reference: P:\Projects\402992 Bloem Recon\FINAL REPORTS\Interventions Report.docx 


Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area 1 

1. BACKGROUND 

1.1 Scope of the Project 

In order to prevent the anticipated shortages in water supply to the Greater Bloemfontein Area, the 

Department of Water Affairs (DWA) initiated a Reconciliation Strategy Study to explore supply and demand 

side interventions that can be implemented to meet anticipated future water requirements. The purpose of 

the Reconciliation Strategy Study was thus to develop an implementation plan of action to ensure that the 

supply of water can meet present and future requirements. The Strategy thus provides a programme of 

studies and other investigations that need to take place so that the necessary interventions are timeously 

investigated to the appropriated level of detail. 

The objective of this study is to develop a strategy that will set out a course of action to ensure adequate 

and sustainable reconciliation of future water requirements in the Greater Bloemfontein Area for at least 25 

years. This study: 

1. Investigated future water requirements scenarios for the Greater Bloemfontein Area; 

2. Investigated possible water conservation and water demand management (WC/WDM) interventions, 

groundwater interventions, re-use of treated effluent, and possible future surface water resource 

development options; 

3. Investigated possible scenarios for reconciling the requirements for water with the available 

resources; and 

4. Provides recommendations for development and implementation of interventions and actions 

required. 

This report describes the interventions that were investigated. 

1.2 Study Area 

The study area comprises those areas served by the large bulk water supply systems which serve the 

Greater Bloemfontein Area, which includes Bloemfontein, Thaba Nchu, Botshabelo, Wepener, 

Dewetsdorp, Reddersburg, and Edenburg. Furthermore, the future water requirements of the rural villages 

surrounding Thaba Nchu, which currently receive water from groundwater sources, werel also be taken 

into consideration. In addition to the urban and rural water requirements, agricultural water requirements 

also formed part of this study, as these water requirements also impact on the reconciliation of supply and 

requirement. The study area is shown in Figure 1.1. 



Figure 1.1: Study Area 

The boundary of the Primary Study Area was 

developed using the municipal boundary of MLM 

and secondary catchments within which 

Bloemwater operates 

The boundary of the Secondary Study Area 

includes the secondary catchments draining 

into the Caledon River 



2. CURRENT INFRASTRUCTURE 

2.1 The Greater Bloemfontein Area Water Supply System 

Bloem Water is the main supplier of bulk potable water to urban centres in the Modder / Riet subcatchment. 

In order to meet current water requirements, water is transferred from the Orange and Caledon 

River Systems. The main transfer water supply schemes are: (1) the Caledon – Bloemfontein transfer 

which supplies Bloemfontein, Dewetsdorp, and small users from Welbedacht Dam, (2) the Maselspoort 

Scheme, and (3) the Caledon – Modder (also known as the Novo Transfer Scheme) which supplies water 

via the Rustfontein Treatment Works to Bloemfontein, Botshabelo, and Thaba Nchu. A brief description of 

these transfer schemes is provided in the following sections. The bulk water supply system serving the 

Greater Bloemfontein Area is shown in Figure 2.1. 

2.1.1 The Caledon – Bloemfontein Transfer 

The Caledon-Bloemfontein pipeline was commissioned in 1974 to supply potable water from the 

Welbedacht Dam on the Caledon River to Bloemfontein, Botshabelo, Thaba Nchu, Dewetsdorp, 

Reddersburg, and Edenburg. As sediment deposition has significantly reduced the yield from Welbedacht 

Dam, Knellpoort Dam was commissioned to supplement the supply. Situated just downstream of 

Welbedacht Dam is the Welbedacht Water Treatment Works (WTW) with a capacity of 145 Ml/day. This 

water is pumped after purification via a 6.5 km pressure pipeline and a 106 km gravity pipeline to 

Bloemfontein. The average capacity of the pipeline is 1.7 m 3 /s and the maximum capacity 1.85 m 3 /s. This 

infrastructure is owned and operated by Bloem Water. 

2.1.2 The Maselspoort Scheme 

The Maselspoort Scheme includes the Maselspoort WTW (110 Ml/day) and the Maselspoort Weir, which is 

located on the Modder River downstream of Mockes Dam (which is downstream of the Rustfontein Dam). 

The Maselspoort WTW supplies approximately 25% of Bloemfontein’s water needs and is owned and 

operated by the Mangaung Metropolitan Municipality (MMM). 



Figure 2.1: Greater Bloemfontein Water Supply Scheme 



2.1.3 The Novo Transfer Scheme 

The Novo Transfer Scheme, which became operational in 1998, includes Tienfontein Pump Station, a 

pipeline and canal from Tienfontein pump station to the Knellpoort Dam, Knellpoort Dam, and the Novo 

Pump Station and pipeline. 

. 

The Novo pump station, which is situated on the northern side of the Knellpoort Dam, transfers water from 

Knellpoort Dam to the Modder River (current installed capacity is approximately 1.5 m 3 /s), via a 20 km 

pipeline running from Knellpoort Dam to the headwaters of the Modder River. From the outfall of the Novo 

pipeline water flows down the Modder River to Rustfontein Dam, a distance of ± 50 km. Water stored in 

Rustfontein Dam is treated at the Rustfontein WTW and pumped to Botshabelo/Thaba Nchu or 

Bloemfontein. As an alternative, water can be released from Rustfontein Dam to flow downstream into 

Mockes Dam from where it can be abstracted at the Maselspoort Weir, treated at Maselspoort WTW, and 

pumped to Bloemfontein. The above infrastructure is owned by DWA and operated by Bloem Water. 

2.2 Potable Water Bulk Infrastructure 

Bloem Water supplies about 100 million m 3 /a to about 580 000 people and is the main supplier of bulk 

potable water to the urban centres in the Modder / Riet River sub-catchment. The total current capacity of 

reservoirs serving the Greater Bloemfontein is 425 Ml (this includes Mangaung Municipality reservoirs). The 

capacity of Bloem Water’s bulk reservoirs is 278 Ml. 

The Thaba Nchu and Botshabelo reservoirs have capacities of 156 Ml and 52 Ml respectively. 

Bloem Water, together with Mangaung Metropolitan Municipality, owns and operates four WTW with 

associated infrastructure, namely: Welbedacht WTW (145 Ml/d), Rustfontein WTW (100 Ml/d), Groothoek 

WTW (18 Ml/d) and Maselspoort WTW (110 Ml/d). 

2.3 Major Wastewater Treatment Works 

The following Wastewater Treatment Works (WWTW) serve Bloemfontein/Mangaung: 

a) Bloemspruit (56 Ml/day); 

b) Sterkwater (10.2 Ml/day); 

c) Welvaart (6 Ml/day); 

d) Bainsvlei (5 Ml/day); 

e) Northern Works (1 Ml/day); and 

f) Bloemdustria (


3. AVAILABLE SUPPLY 

3.1 Surface Water 

Nearly 70% of the total surface runoff, which would flow through the Upper Orange Water Management 

Area (WMA) under natural conditions, originates from Lesotho and just more than 30% from within the 

WMA. The surface water resources, both within the WMA and in Lesotho, are well developed and have a 

high degree of utilisation. 

The two largest dams in this WMA are the Gariep and Vanderkloof dams, which reduce the incidence of 

floods in the Lower Orange WMA by about 50%. Other major dams are the Welbedacht and Knellpoort 

dams in the Caledon catchment and the Krugersdrift, Rustfontein, and Kalkfontein dams in the Modder-Riet 

River catchment. A description of the major dams per sub-catchment is provided in the following sections. 

3.1.1 Caledon River Sub-catchment 

The Welbedacht Dam is situated on the Caledon River and supplies water to urban users in Bloemfontein, 

Botshabelo, Dewetsdorp, and various other smaller users, as well as irrigators downstream of Welbedacht 

Dam along the Caledon River. The irrigators downstream of Welbedacht Dam have no claim to any water 

stored in Welbedacht Dam. Only the inflow can be released for irrigation purposes. The Welbedacht WTW 

at Welbedacht Dam supplies water via the Caledon-Bloemfontein pipeline to Bloemfontein, Botshabelo, and 

other minor consumers. 

Due to the decreasing yield of the Welbedacht Dam as a result of siltation and the increasing demand on 

the Caledon-Bloemfontein Regional Water Supply Scheme, the DWA supplemented the yield of the 

Welbedacht Dam by constructing the Knellpoort off-channel storage dam on the Rietspruit, a tributary of the 

Caledon River. Knellpoort Dam is supplied with water from the Caledon River by the Tienfontein Pump 

station. Water pumped from the Caledon River into Knellpoort Dam is then released back into the Caledon 

River to allow abstraction at Welbedacht Dam by Bloem Water all year round. Furthermore, the Novo 

Transfer pump station is located at the Knellport Dam and is able to transfer water into the Modder River, 

which supplied the Rustfontein and Mockes Dams. 

Since 1973, when Welbedacht Dam was completed, the dam has lost more than 90% of its storage 

capacity due to the high siltation rates. Since there is minimal storage capacity in Welbedacht Dam, the 

Tienfontein pumps must operate at a high reliability on a run-of-river basis to supply Knellpoort Dam. The 

current pumps have a total discharge of approximately 2.5 m 3 /s (design 3 m 3 /s) and have experienced high 

maintenance costs as a result of fine debris and sediment which reach the pumps. 

Tienfontein pump station is seen as the most critical component of the water supply infrastructure supplying 

Bloem Water with raw water, as Bloem Water receives approximately 70% of its water supply from 

Welbedacht Dam (via Tienfontein Pump station and Knellpoort Dam). 

3.1.2 Modder River Sub-catchment 

Krugersdrift Dam is located on the Modder River and supplies water for irrigation purposes to the Modder 

River Government Water Scheme. More than 50 weirs are constructed in the Modder River between the 

dam wall and the confluence with the Riet River. 

Mockes Dam on the Modder River supplies water to Bloemfontein via the Maselspoort WTW. Groothoek 

Dam is located on the Kgabanyane River, a tributary of the Modder River, and supplies water to Thaba 

Nchu. 



Rustfontein Dam is located on the Modder River and forms the major storage reservoir in the Modder River. 

Water is released from Rustfontein Dam to supplement the abstraction from Mockes Dam and currently 

provides the major portion of water supplied to Bloemfontein at Maselspoort. 

3.1.3 Riet River Sub-catchment 

Tierpoort Dam is situated on a tributary of the Riet River upstream of Kalkfontein Dam and supplies water 

to the Tierpoort Irrigation Board through a network of unlined canals. 

Kalkfontein Dam is on the Riet River and supplies water for irrigation through a network of canals and 

syphons to the Riet River Government Water Scheme. Urban water is also supplied to the towns 

Koffiefontein and Jacobsdal through the canal system. 

3.1.4 Upper Orange River 

The Gariep Dam and the Vanderkloof Dam are the two largest reservoirs in South Africa and are both 

situated in the Upper Orange River. These two reservoirs form the main component of the Orange River 

Project and are utilised to supply water to urban and irrigation users. They are also used for hydro power 

generation and flood control. 

3.1.5 Lesotho 

The Katse Dam in the Senqu sub-area is used for transfer of water to the Upper Vaal WMA. Mohale Dam, 

in the same sub-area, is also used to transfer water to the Upper Vaal WMA. Metlolong Dam in, which is 

under construction in Lesotho on a tributary of the Caledon River, will be completed in 2013. It will supply 

water to Maseru and surrounding towns. 

3.2 Groundwater 

Groundwater is currently not utilised for the supply of potable water to Bloemfontein. However, groundwater 

is used by individuals for irrigation of gardens in residential areas and groundwater is used extensively for 

agricultural purposes in the Bainsvlei / Kalkveld area and in the area to the south-west of Bloemfontein. 

Groundwater is also utilised by small industry for bottling of water as well as micro irrigation of vegetables 

and nurseries (garden centres), which are in close proximity to the city limits. 

Small towns and communities in the vicinity of Bloemfontein, such as Dewetsdorp, Reddersburg, Edenburg, 

Wepener, and Excelsior, are partially dependent on groundwater for drinking and domestic purposes. 

Groundwater is therefore considered as an essential resource, specifically for the smaller towns. 

3.3 Summary of Water Resources Serving the Greater Bloemfontein Area 

The Greater Bloemfontein area currently utilises surface water from three primary sources, namely the 

Welbedacht/Knellpoort system, Rustfontein Dam and Mockes Dam. The historical firm yields of these 

sources of raw water (excluding river and other conveyance losses) have been determined in previous 

studies and verified in this study to be as shown in Table 3.1, where the registered water use is also 

shown. 



Table 3.1: Summary of Primary Surface Water Resources 

Source Registered Water Use (Mm 3 ) Yield (Mm 3 ) 

Rustfontein Dam 9.74 

Mockes Dam 14.8 

8 

Groothoek Dam 0.74 

Welbedacht/Knellpoort System 37 92 

Totals 62.28 100 

In the current study, the yield analyses conducted in previous studies were first verified and, after that, the 

yield model was modified to take account of more recent information on the operation of the system and 

additional hydrological data. 

The determination of the yield of the combined system is complex and is affected by the assumptions made 

about losses in the system and the way in which the system is operated. The yield analysis is described in 

detail in the Reconciliation Strategy Report, and only the more important results are presented here. 

Table 3.2: Adjustment of the Yield to Incorporate Recent Operating Information and Hydrology 

Impact 

Model Adjustment 

on Yield 

Implement Tienfontein Pump operation described in "Extension of the capacity of the Novo 

Transfer Scheme - Study (EB/2009/5) by V&V Consulting Engineers. According to this 

-7 

report the pumps transfer 1 m 3 /s when the inflow reaches 4 m 3 /s, 2 m 3 /s when the inflow 

reaches 6 m 3 /s and 3 m 3 /s when the inflows reached 10 m 3 /s. 

Replace Welbedacht's average WTW capacity of 124 Ml/d with the equivalent seasonal 

-4 capacity that is lower in summer (100 Ml/d due to siltation problems) and higher in winter 

(145 Ml/d). 

-3 Introduce 10% conveyance loss on the pipeline from Welbedacht to Bloemfontein 

-3 Reduce Welbedacht live storage from 11.7 to 6.6 million m 3 

Replace Caledon System upstream of Welbedacht with a present day streamflow sequence 

developed during the Orasecom Study - kindly provided by Bennie Haasbroek. The 

-3 demands downstream of Welbedacht from the Orange River System Analysis were retained 

while the Orasecom Study was checking why the new demands(14 million m 3 /a) were 

significantly lower than the earlier demands (35 million m 3 /a) 

Implement Knellpoort Pump operation described in "Extension of the capacity of the Novo 

Transfer Scheme - Study (EB/2009/5) by V&V Consulting Engineers. According to this 

3 

report the transfer varies from 1.5 m 3 /s when the storage level in Knellpoort is above 

RL1436 m and 1.67 m 3 /s at RL1452.1 m. 

Model 35 million m 

1 

3 /a irrigation located d/s Welbedacht Dam d/s of the dam (as opposed to 

u/s) and release all water up to 2 m 3 /s flowing into Welbedacht when Knellpoort + 

Rustenberg Storage > 150 Mm 3 , reduce to 25% (0.5 m 3 /s) when less 

-16 Total net impact 

When various operational constraints and the estimated environmental water requirements downstream of 

Welbedacht Dam, as well as existing and proposed agricultural water requirements, which include the 

water requirements for resource poor farmers, are taken into account, the combined historical firm yield 

shown in Table 3.1 is reduced by 16 million m 3 /a to 84 million m 3 /a. The factors contributing to this 

reduction are shown in Table 3.2. 



There are a number of factors which have potential influences on the available yield of the Greater 

Bloemfontein System and therefore potential impacts on the water availability and reconciliation of supply 

and requirement. These factors are shown in Table 3.3 below together with the potential consequential 

impact on the available system yield. 

Table 3.3: Factors with Potential to Influence Net System Yields 

Factor which could Influence Available Yield 

Impact of Metolong Dam. Metolong Dam which is situated on a tributary of 

the Caledon River will start impounding water in approximately mid-2012. 

This will have an impact on the flows into the Caledon River and will 

subsequently reduce the amount of yield available. 

Impact of Environmental Water Requirement: When the EWR 

requirements are implemented on the Caledon River, there will be less 

surplus water available to transfer to Knellpoort Dam and therefore there will 

be a reduction in the overall yield of the system 

Capacity of Welbedacht WTP: Due to the high turbidity of the raw water, 

especially during flood events it is not possible to operate Welbedacht WTP 

at full capacity throughout the year. A discussion with the operator of the 

WTP suggested that the WTP could operate at full capacity of 145 Ml/d in 

winter, but only managed an output of between 90 and 100 Ml/d in summer 

when the silt load in the river was higher. The yield could be increase if the 

WTP was operated a full capacity all year round 

Operation of Knellpoort Dam: Due to the high electricity costs of pumping 

surplus water from the Caledon River into Knellpoort Dam, Knellpoort Dam 

has in the past been operated up to a maximum capacity of approximately 

60%. This operational rule would decrease the available yield of the system 

Risk of non supply as a result of continuous failure (bursts) on the 

Welbedacht pipeline: 

Impact on Yield 

(million m 3 /a) 

Interventions Report June 2012 

-1 

-2.21 

+7.06 

The construction of Metolong Dam and the implementation of the Environmental Water Requirements are 

two interventions which will be implemented in the short term. It is therefore proposed that the impact on 

the yield of these two interventions is factored into the scenario planning and should ultimately form the 

baseline available yield. For planning purposes the historical firm yield of the system with these 

interventions in place was therefore assumed to be 81 million m 3 /a. 

-3.3 

-6.86


4. WATER REQUIREMENTS 

4.1 Existing Requirements 

4.1.1 Urban Water Requirements of the Greater Bloemfontein Area 

Bulk water consumption data (2006 to 2009) provided by Bloem Water (BW) and MMM is summarised in 

Table 4.1. Groundwater is utilised by some of the smaller towns to augment water supply. The abstraction 

of groundwater for bulk water supply has not been included in Table 4.1. 

Table 4.1: Metered Bulk Water Consumption for Towns Supplied with Water from the Greater 

Bloemfontein System (Excluding Groundwater) 

Year/ 

Supplier 

2008 2009 2010 2011 

BW MMM Total BW MMM Total BW MMM Total BW MMM Total 

Town million m 3 /a million m 3 /a million m 3 /a million m 3 /a 

Bloemfontein 40.66 20.31 60.97 35.83 30.13 65.97 37.1 27.71 64.82 37.91 22.72 60.63 

Botshabelo 8.18 8.18 9.21 9.21 7.87 7.87 10.06 10.06 

Thaba Nchu 5.14 5.14 4.64 4.64 6.04 6.04 6.3 6.3 

Excelsior 0.17 0.17 0.16 0.16 0.19 0.19 0.17 0.17 

Wepener 0.80 0.80 0.82 0.82 0.75 0.75 0.74 0.74 

Dewetsdorp 0.84 0.84 0.92 0.92 0.96 0.96 0.76 0.76 

Reddersburg 0.85 0.85 0.86 0.86 0.69 0.69 0.43 0.43 

Edenburg 0.53 0.53 0.53 0.53 0.53 0.53 0.43 0.43 

Total 57.19 20.31 77.48 52.97 30.13 83.11 54.13 27.71 81.84 56.80 22.72 79.52 

Mangaung Metropolitan Municipality purchases approximately two thirds of its potable water form Bloem 

Water. Table 4.1 shows the amount of bulk water which was supplied from the Bloem Water System and 

from MMM’s own sources for the period 2008 through to 2011. From Table 4.1 it is evident that the water 

supplied to smaller towns accounts for only 4% of the total bulk water consumption. 

Figure 4.1 below shows the bulk water supplied from the Greater Bloemfontein System from 1992 through 

to 2011. With the exception of the period 1999 through to 2001 and the last two years there has been a 

year on year positive growth in water requirement. 



Figure 4.1: Metered Bulk Water Supplied from the Greater Bloemfontein System 

The following is noted with regard to the historical water consumption for Bloemfontein and surrounds 

since 1993: 

Period of 1993 to 1999: An average annual increase in water consumption of approximately 9% per 

annum possibly triggered by an improvement in levels of service and delivery of basic services through 

the Government’s various infrastructure programs. In addition, a significant number of people from 

surrounding areas (urban and rural centres) relocated to Bloemfontein for employment and other 

economic opportunities. 

Period of 2003 to 2009: An average annual increase in water consumption of approximately 5.8% per 

annum. This could possibly be attributed to a growth in local economy, supported by an improvement 

in levels of services in the poorer communities through various government projects like the 

eradication of the bucket system, provision of on-site water projects, and numerous low income 

housing projects. 

Period of 2010 to 2011: A decrease in water requirement possibly due to above average rainfall in the 

two years, and also potentially the implementation of Water Conservation/Water Demand 

Management. 

The average long term growth rate in the water requirement for the period 1993 through to 2011 

(18 year period) was 5% per annum. 

Figure 4.2 below shows the annual system input volume of MMM (bulk purchases from Bloem Water as 

well as Maselspoort production) as well as the authorised consumption. The difference between the bulk 

water purchases and the authorised consumption (billed authorised and unbilled authorised) represents the 

apparent and real losses in the system. 



Figure 4.2: MMM Water Consumption 

The following conclusions can be drawn from Figure 4.2. 

1) Losses have increased significantly since 2006. 

2) The real and apparent losses in the system are 30 million m 3 /a. This represents approximately 37.5% 

of the annual system input volume. 

3) Authorised water consumption has been growing at an average rate of 3% per annum over the 

period 2007 through to 2010 and on average by 1.7 % over the period 2005 through to 2010. 

4.1.2 Breakdown of Urban Consumption 

Figure 4.3, Figure 4.4 and Figure 4.5 provide a breakdown of potable water use as derived from the 

2006/07 Water Service Development Plan for Bloemfontein, Botshabelo, and Thaba Nchu. More recent 

figures were unfortunately not available. In the Bloemfontein area, “unaccounted for water” constitutes 39% 

of the total annual consumption. The second largest water consumption, accounting for 37% of the total 

annual consumption, is “residential use”. Thirteen percent of the water is used for commercial purposes, 

8.5% is classified as other, and 2% for industrial water. 

Figure 4.3: Current Water Use for Bloemfontein 



In Botshabelo, the largest proportion of the current water use is residential use, representing 40.5% of the 

total use. “Unaccounted for water” comprises 31% of the total metered bulk water supplied. Commercial 

use accounts for 20% and other supply accounts for 8%. 

Figure 4.4: Current Water Use for Botshabelo 

In Thaba Nchu, physical losses (unaccounted for water) accounts for 94% of the total water use, while 

residential and commercial use accounts for 3.5% respectively. 

Figure 4.5: Current Water Use for Thaba Nchu 

4.1.3 Agricultural Water Requirements 

For the purposes of this study, agricultural water requirements were considered in two areas, namely: 

1) in the Modder-Riet Catchment upstream of Krugersdrift Dam; and 

2) along the Caledon River. 

Figure 4.6 shows the registered water use and resource allocation in the quaternary catchments 

surrounding the Greater Bloemfontein Area. Based on the allocations to the different water sectors 

(agriculture and urban), it is evident that the two sectors do not share any allocation from dams situated 

within the Modder-Riet Catchment upstream of Krugersdrift Dam. 

In terms of the yield modelling of the Welbedacht/Knellpoort System, the existing agricultural water 

requirements along the Caledon River, both upstream and downstream of Welbedacht Dam, and the 

proposed water requirements of the resource poor farmers, were taken into account. 



Figure 4.6: Registered Water Use and Resource Allocation in the Quaternary Catchments Surrounding the Greater Bloemfontein Area 



4.2 Future Water Requirement 

4.2.1 Understanding growth in Water Requirements 

The prediction of water requirements for master planning purposes, or for a study of this nature, is usually 

based on the primary drivers of water demand, which are population growth and local economic growth. 

These two factors are interlinked to some extent, as economic growth may stimulate population growth as a 

result of migration from the rural areas or other urban area with a poor economy. There are also numerous 

other factors that can impact future water requirements, and specifically for the Greater Bloemfontein area, 

these may include: 

Change in the level of service, as improvements in the water services, sanitation, and health 

awareness will most likely impact on future requirement scenarios. Typical initiatives in the study 

area include the eradication of water and sanitation backlogs linked to the UN Millennium Goals, as 

well as the delivery of houses to the poor to meet SA National target with regard to housing. 

The impact of HIV/AIDS is a significant factor, with the highest occurrence in the rural areas of South 

Africa. 

Improvement in water management in terms of water meter coverage, the extent and accuracy of 

meter reading and billing, and the effectiveness of credit control policies. 

The historic growth in water requirement has not been consistent, and has fluctuated quite significantly. 

The water growth has included periods of negative or relatively flat growth possibly as a result of above 

average rainfall being experienced in these specific years. 

Water use, when expressed on a per capita basis, is in the region of 200 litres per person per day. There 

are uncertainties, however, associated with the future population growth rate figures as described below. 

4.2.2 Population Growth Rates 

Population growth rates are based on the birth rate, mortality rate, and migration. The following sources 

and references were found which described the historic and possible future population growth rates. 

Information taken from the IDP report 2007/2008 for Mangaung Metropolitan Municipality indicates 

that the future population growth rate for Bloemfontein will be 3.1% per annum. The growth in 

population between 1996 and 2001 based on 2001 Census figures for the Bloemfontein areas was 

estimated to be 3.1% per annum. 

A report entitled “Identification of Bulk Engineering Infrastructure in Support of Housing Development 

in Mangaung, Masterplan prepared for Mangaung Metropolitan Municipality determined that the 

anticipated population growth figures for Bloemfontein up to 2030 would be 1% per annum 

Population projection scenarios were also developed for the All Towns study for Central Region 

(June 2009). This study proposed two alternative population growth scenarios, a High Population 

Growth Scenario and a Low Population Growth Scenario. The high population growth scenario 

translates to an aggregate population growth rate for Bloemfontein, Botshebelo and Thaba Nchu of 

1% per annum, whilst the low population growth scenario translates to an aggregate population 

growth rate of 0% per annum 

Migration is proportional to economic growth rate, implying a strong economic growth will result in 

“immigration” whereas a decline in economic growth will result in “emigration”. Migration figures that 

could be relevant to the study area were sourced from Provincial trends as abstracted from the “2009 

StatsSA Mid-Year Projections for the Orange Free State Province (2006 to 2011 Projection)”. 

Migration affects the rural and smaller towns more significantly, as a result of people seeking 

economic and employment opportunities in the larger urban centres. Migration is assumed to vary 

between 0.00% and 0.25% for Bloemfontein and Botshabelo, assuming more people migrating to, 

and residing in these towns. For the smaller towns with less economic opportunity, the migration 



rates vary from between -0.4% and 0.0%. The assumption is that current residents could be leaving 

the smaller towns to reside and seek opportunities in the larger centres. 

The impact of HIV/AIDS is a significant factor when estimating population projections, and more 

specifically, its influence on the mortality rate. The impact of HIV/Aids relevant to the Study area has 

been based on National statistics, where the highest occurrence is in the rural areas of South Africa. 

The mortality rate as a result of HIV/Aids has been assumed to be as high as 0.4% for the urban 

towns, and as high as 0.75% for the rural towns and villages. 

4.2.3 Economic Growth Rates 

Bloemfontein is currently the largest urban centre, followed by Botshabelo and Thaba Nchu and most public 

and private investment will be in these areas. The latest Integrated Development Plan (IDP) projects that 

Bloemfontein will remain the focus for future development as it is predicted that Bloemfontein will house 

approximately 65% of the total population by 2016. 

The economy of the MMM plays a significant role in the Motheo District economy (92,5%) as well as the 

Free State economy (25,5%), but it is relatively small when compared to the national economy (1,6%). 

Of importance is the relatively small share of the local agriculture, mining and manufacturing sectors 

compared to the province and the country. Mining’s small share is understandable as the Mangaung area 

competes with the Goldfields area, which is very strong in mining, however the share of agriculture and 

manufacturing is disturbingly low. On the other hand, the tertiary sector of the local economy is very 

significant within the context of the province. 

Approximately 87% of economic production in the MMM area occurs in Bloemfontein while only 7% and 6% 

respectively occur in Botshabelo and Thaba Nchu. 

The overall annual economic growth rate for the Mangaung area was 3.59% between 2001 and 2004 and a 

significantly higher growth of 9.5% occurred between 2004 and 2007. In Bloemfontein an economic growth 

rate between 2004 and 2007 of 9.86% was recorded compared with 8.55% in Botshabelo, while that of 

Thaba Nchu was considerably less at 5.08% per annum. This confirms the fact that the Bloemfontein 

economy is and will be increasing its proportional share of the economy. 

While community services contribute to over a third of Mangaung’s economy, other prominent sectors 

include finance, retail and trade, transport, and manufacturing. The remaining sectors such as agriculture 

and mining are very small and make a minor contribution to the local economy. Community services 

contributes 35% to the city’s economy, transport 13%, finance 18%, agriculture 4%, manufacturing 8%, 

trade 16%, utilities 3% and construction 3%. 

Growth in the transport sector, given the strategic central location of Bloemfontein, is likely to be stimulated 

by increasing economic activity elsewhere in the country. 

4.2.4 Future Water Requirement Scenarios 

The following assumptions were made for the development of the future water requirement scenarios from 

the Greater Bloemfontein Water Supply System. 

High Growth Water Requirement Scenario will take place on account of high population growth 

rate and high economic growth rates. Given the relatively low population projection growth rates 

and the contrasting relatively high historic growth in water requirements (the authorised billed and 

unbilled water consumption figures for the last 3 years have grown at a rate of 3% per annum) it 

was decided to use long term historical growth rate of 3% per annum as the basis for the high 

growth scenario. 



Low Growth Water Requirement Scenario will take place on account of low population growth 

and low economic growth. It was decided to base the low growth scenario on a growth in water 

requirement of 1% per annum. 

Figure 4.7 presents the proposed high and low water requirement scenarios. The actual water requirement 

is also shown on the graph. The high and low water requirement projections have been projected from the 

2009 base for the following reasons: 

There were significant summer rains in the 2011 and this may have resulted in a depressed 

demand. 

It is still too early to ascertain whether or not the drop in 2010 can be ascribed to structural reasons 

(e.g. improved metering, WC/WDM) or is as a result of climatic influences. 

It is conservative to plan from a higher base. As future years actual water requirements become 

known, the base from which the projections are made can always be changed. 

Figure 4.7: Water Requirement Scenarios for the Study Area 

Important Qualification 

High Growth Scenario (3%) 

Actual Water Requirement 

Low Growth Scenario (1% p.a.) 

It is important to note that the water requirement scenarios presented above were developed during a 

global economic crisis. The global recession and a slow recovery from this recession are likely to have 

significant implications for water requirement growth projections for the Greater Bloemfontein Water Supply 

System. 

The implications of the recession for the strategy to meet future water requirements are as follows: 

The economic uncertainty increases uncertainty concerning the growth in water requirements. 

Water use must be continuously and carefully monitored; 

Future scenarios/projections need to be revised frequently, based on updated information; 

Planning to increase water availability needs to be as flexible as possible; and 

Interventions that are more flexible in terms of timing should be favoured, all other considerations 

being equal. 



4.2.5 Agricultural Water Requirements 

The only expected growth in irrigation requirements is the allocation of 12 000 ha to resource poor farmers. 

The effect of the 12 000 ha (4 000 ha for the Upper Orange WMA, 4 000 ha for the Lower Orange WMA, 

and 4 000 ha for the Fish-Tsitsikamma WMA) is estimated to be in the region of 114 m³/a. The 

Implementation Strategy for the development of 3 000 ha irrigation in the Free State Province indicates that 

there is ± 200 ha available near Ficksburg (Caledon River) and ± 2 000 ha available next to the Orange- 

Riet Canal, which starts at the Vanderkloof Dam. The agricultural water requirement for the 200 ha near 

Ficksburg was taken into account in the determination of the available yield. 



5. WATER BALANCE 

5.1 The Orange River System 

The Upper Orange WMA is a component of the extended Orange and Vaal River System. This has been 

the subject of various water balance and reconciliation studies. The latest water balance from the Orange 

River system indicated a surplus of 333 million m³/a for the year 2000. This surplus yield reduced to 158 

million m³/a in 2003 when Mohale Dam was commissioned, due to the fact that more water could be 

transferred out of the system to the Upper Vaal WMA. Although the Mohale Dam increased the local yield 

in the Upper Orange, the increase in yield is transferred to the Upper Vaal WMA and cannot be used in the 

Upper or Lower Orange WMAs. The effect of Mohale Dam can be seen in that the surplus yield is reduced 

from 333 million m³/a to 158 million m³/a. 

When the effect of the 12 000 ha earmarked for resource poor farmers is taken into account, the surplus of 

158 million m³/a will reduce further to only 44 million m³/a. This surplus is reserved for the growth in 

demands in the urban, industrial, and mining sectors in the Upper Orange WMA, the Lower Orange, and 

the Fish to Tsitsikamma WMAs. 

The future Polihali Dam site is situated on the Senqu River approximately 1.5 km downstream of the 

confluence of the Senqu and Khubelu Rivers. Polihali Dam would increase the water delivered from 

Lesotho Highlands Water Project to the high value industries in the Vaal catchment, but would, in the long 

term, result in a reduction in the water available at downstream Gariep and Vanderkloof dams. It is 

envisaged that the Polihali Dam would reduce the yield of the Orange River downstream by approximately 

283 million m 3 . This is based on the assumption that overall yield of the system increases by 182 million 

m 3 /a but an additional 465 million m 3 /a might be transferred to Gauteng, causing a shortfall of 283 million 

m 3 /a (465 – 182 = 283). 

Table 5.1 shows a mass water balance of the Upper Orange WMA. 

Table 5.1: Orange River Water Balance 

Surplus Yield 

(million m 3 ) 

Year 2000 Surplus Yield 333 

Less Transfer to Gauteng from Mohale Dam (impact on Orange River) -175 

Net available yield 158 

Less Allocation for Resource Poor Farmers -114 

Net current available yield for growth in urban water requirements 44 

Less growth in urban, industrial, and mining sectors in the Upper Orange WMA, the 

Lower Orange, and the Fish to Tsitsikamma WMAs (NWRS 2025 base case) 

-90 

Net deficit in Yield in 2025 -46 

Less Transfer to Gauteng from Polihali Dam (impact on Orange River in 2053) -283 

Anticipated net deficit in 2053 (will be higher with additional growth in urban 

water requirements) 

-329 

The Upper Orange WMA has a large commitment to support the local water requirements and transfers to 

the Upper Vaal WMA, the Fish to Tsitsikamma WMA, as well as release obligations to the Lower Orange 

WMA. A number of augmentation interventions have been identified to provide additional yield to the 

Orange River System to make up the envisaged shortfall caused by transfers from Polihali Dam to the 

Gauteng area. Some of the interventions identified include: using the lower level storage in Vanderkloof 

Dam; the construction of Bosberg/Boskraai Dams; and the raising of Gariep Dam. 



It is the intention of the DWA to initiate a separate reconciliation strategy study on the Orange River 

System, which will draw on the information from the Greater Bloemfontein Reconciliation Strategy Study. 

5.2 The Greater Bloemfontein Area 

The anticipated surplus yield in the Orange River System (including the Caledon River) is approximately 44 

million m³/a. According to the Internal Strategic Perspective for the Upper Orange River WMA, this surplus 

is reserved for the growth in demands in the urban, industrial, and mining sectors in the Upper Orange 

WMA, the Lower Orange, and the Fish to Tsitsikamma WMAs. 

It is not anticipated that there will be any further growth in agricultural water requirements in the Greater 

Bloemfontein Area (with the exception of the allocation made to the resource poor farmers). As the 

agricultural sector and urban sector in the Greater Bloemfontein Area and surrounds do not share any yield 

from a common surface water resource, it is possible to undertake a reconciliation of supply and 

requirement based on the current urban water requirements and available yield of the surface water 

schemes serving the Greater Bloemfontein area and surrounds. 

Figure 5.1 illustrates the comparison of available surface water supply and current water requirements for 

the High and Low water requirement scenarios in the Greater Bloemfontein Area. The current water 

requirement (based on 2009 data) is approximately 83 million m 3 /a while the available supply is 84 million 

m 3 /a (Historical Firm Yield). 

High Growth Scenario (3%) 

Figure 5.1: Surface Water Balance for Study Area 

Low Growth Scenario (1% p.a.) 

It appears that the 2009 water requirement was in balance with available supply (historical firm yield) 

and any increase in use (as predicted by the high and low water requirement scenarios) would put the 

system at risk. The higher the growth in water requirements, the higher the risk would be. It is clear 

that measures to increase the surety of supply need to be implemented as soon as possible. This 

includes measures to increase the supply of water as well as WC/WDM measures to reduce the 

demand. 



6. ISSUES WHICH COULD IMPACT ON THE RECONCILIATION OF SUPPLY 

AND REQUIREMENT 

There are a number of issues which could impact on the reconciliation of supply and requirement in the 

longer term. These issues are listed below: 

Sedimentation; 

Surface and groundwater quality; 

Migration of people from the rural areas to the urban centres, particularly Bloemfontein; 

Impact of HIV/Aids; 

Illegal use of water; 

Effectiveness of WC/WDM; and 

Existing bulk water supply infrastructure capacity i.e. bulk water pipelines and water treatment works. 



7. INTERVENTIONS SELECTED FOR PRELIMINARY EVALUATION 

7.1 Process 

The Greater Bloemfontein Reconciliation Strategy study has produced a long-term strategy for the 

management of reconciling water supply with demands. Following the determination of the water balance, 

the Strategy followed a step-wise process to identify the most favourable interventions, or groups of 

interventions, to meet possible future water requirement scenarios. The process is listed below: 

Step 1: Identification of interventions 

Step 2: Preliminary screening of interventions 

Step 3: Key stakeholder review of selected interventions 

Step 4: Scenario planning process 

Step 5: Review of selected scenarios by the Study Steering Committee 1 

Step 6: Obtaining public feedback on the scenarios 

Step 7: Implementing interventions and initiating studies of interventions 

This document records details of the interventions that were identified in Step 1 and describes the 

procedure followed in Step 2, where the preliminary screening of interventions was achieved by means of a 

Preliminary Screening Workshop. 

Based on the outcomes of the Preliminary Screening Workshop, a preliminary list of interventions that 

needed to be investigated further at reconnaissance/pre-feasibility level was documented in the Inception 

Report which, in turn, informed the first draft of the Preliminary Strategy. A second workshop, held later in 

the Study, helped inform the final Strategy. The final strategy includes a list of studies that the DWA should 

undertake in order to ensure an ongoing reconciliation of supply and requirement. 

7.2 Objectives of the Preliminary Screening Workshop 

The Preliminary Screening Workshop was intended to present potential interventions in terms of timing, 

cost, and yield. Combinations of different interventions were also considered to devise the set of best 

possible alternatives to meet the water requirements of the Greater Bloemfontein Area. The objectives of 

the initial screening workshop were to: 

Assess the acceptability of the various interventions identified in previous studies in terms of 

technical, financial, environmental, and social criteria; 

Ascertain which intervention or combinations thereof would warrant further investigations at 

reconnaissance or pre-feasibility level, and what aspects should be investigated in this study; 

Augment the existing information with specialist inputs from the DWA and other key stakeholders; 

and 

Identify any other issues/concerns of stakeholders which could impact on the reconciliation of supply 

and requirement. 

7.3 Screening Workshop Starter Document 

A Screening Workshop Starter Document was drawn up to provide information for discussion purposes. 

The content was based on available documentation which could be used for strategic level decisions. The 

workshop participants provided further information and critically reviewed the information contained in the 

Starter Document. 

1 The Study Steering Committee includes representatives from DWA Head Office and DWA Regional Office, Mangaung Metropolitan 

Municipality, Motheo District Municipality, Naledi Municipality, Bloem Water, Department of Agriculture, Department of Rural 

Development and Land Reform, and water user associations. 



For certain of the options presented in the document, an attempt was made to estimate the yields after 

allowance for the best available estimate of the Reserve. It is however acknowledged that provisional 

Reserve estimates present a degree of uncertainty. Nevertheless, an attempt was made to at least show a 

reasonable order of magnitude of its potential impact. 

The purpose of the Starter Document was to provide adequate background material to facilitate informed 

discussion at the Screening Workshop in order to confirm the development options that may warrant further 

investigation. This report is based on the Starter Document, but the original data on potential interventions 

that was contained in that document has been replaced, wherever possible, by more reliable information 

that became available in the course of developing the Strategy. 

7.4 Attendance at workshop 

The workshop attended by identified DWA staff, the consultant team and supporting specialists, officials 

from Bloem Water, representatives from MMM, representatives from the irrigation boards / WUAs, and 

members of the Study Steering Committee. 

7.5 Selection criteria 

7.5.1 Methodology 

The screening of the various interventions was based on a number of criteria, namely: 

Potential scheme yields, inclusive of the impact of the Reserve; 

Updated financial cost estimates and unit reference values (URVs); 

Socio-economic impacts; and 

Environmental impacts. 

Non-starter (also known as “red flag”) interventions were identified, and criteria under which such 

interventions would be considered again were also identified. Each criterion was assigned a colour-coded 

rating, based on how favourable the intervention was rated for that particular criterion. 

A three tier rating system, as follows, was used: 

Favourable 

Moderately favourable 

Unfavourable 

The following diagram illustrates three hypothetical cases: 

SCHEME 

NAME 

CRITERIA 

URV Socio-economic Environmental Comments 

Scheme 1 Red flag intervention 

Scheme 2 Further investigation 

Scheme 3 URV unfavourable 



Those operations which appeared to be obvious non-starters were flagged. Comment was also made as to 

the extent of available information and whether the technology had been successfully utilised previously or 

elsewhere in the country or internationally. 

7.5.2 Costing 

Where possible, capital costs were based on costs available from previous studies. These costs were 

then escalated based on Contract Price Adjustment (CPA) indices to be representative of the base year 

costs (June 2009). 

An evaluation period of 50 years was selected for all water augmentation schemes, for determination of 

URVs. Discount rates of 6%, 8%, and 10% were used in URV calculations, to cater for funding by both 

MLM and the DWA. Multiplication factors were applied to allow for additional costs as follows: 

Preliminary and General costs of 20% were first added to the capital costs; 

A 10% Contingency sum was then added to the previous sub-total; 

A 15% Professional fees/site supervision sum was further added to the previous sub-total, to get the 

total construction cost estimate; 

The total construction cost estimate was spread over the first two financial years in the URV 

calculation; and 

VAT is excluded in URV calculations 

Equipment replacement periods for pumps (mechanical and electrical), pipelines, etc and desalination 

membranes were not considered. 

Capital costing and determination of URVs was undertaken at a conceptual level. Potential future electricity 

increases were not allowed for in URV calculations. Demand profile was assumed to be constant. Cost of 

electricity was assumed to be 35c/kWh for Eskom and 58c/kWh for Centlec (the local distributer). The 

Centlec supply was assumed for the water re-use options. 

7.5.3 Outcomes of Preliminary Screening Workshop 

The proceedings of the Preliminary Screening Workshop are bound into this document as Appendix 1. The 

comments and recommendations made at the workshop were taken into account when refining proposed 

interventions and developing reconciliation scenarios during the remainder of the study. 

7.5.4 Refinement of Selected Potential Interventions 

After the Preliminary Screening Workshop, selected interventions were refined by improving cost estimates 

and carrying out more detailed determinations of the effects that the interventions would have on the yield 

of the water resources system if implemented. The refined interventions, as used for the final scenarios, are 

described in the remainder of this document. Details of estimates of capital and operating and maintenance 

costs for the interventions are contained in Appendix 2 and the calculation of unit reference values is shown 

in Appendix 3. 



8. SELECTED POTENTIAL INTERVENTIONS 

SECTION A: Urban Water Conservation and Demand Management 

A1: Efficient use of water 

A2: Loss management 

SECTION B: Agricultural Water Conservation and Demand Management 

B1: A range of Interventions is described 

B2: Agricultural Irrigation Audit Upstream of Maselspoort - Weir with Improvement for 

Catchment C52A 

SECTION C: Surface Water Interventions 

C1: Utilising surplus capacity in the Orange River system by pumping to Knellpoort Dam from Gariep 

Dam 

C2: Utilising surplus capacity in the Orange River system by pumping to Knellpoort Dam from 

VanderKloof Dam 

C3: Utilising surplus capacity in the Orange River system by pumping to Knellpoort Dam from Bosberg / 

Boskraai Dam 

C4: Modifications to Welbedacht Dam: Extend scour operations & Lower Outlets 

C5: Modifications to Caledon Modder System. 

C6: Polihali Dam – Lesotho Highlands Phase 2 

SECTION D: Re-use of treated effluent 

D1: Planned direct re-use – New North Eastern 

D2: Planned indirect re-use – Transfer to upstream of Mockes Dam 

D3: Planned indirect re-use – Krugersdrift Dam 

D4: Planned direct re-use – Bloemspruit 

D5: Re-use of treated effluent – Direct use: irrigation 

SECTION E: Groundwater 

E1: Ikgomotseng aquifer 

E2: Bloemfontein aquifer 

E3: Thaba Nchu aquifer 

E4: Reddersburg aquifer 

E5: Edenburg aquifer 

E6: Dewetsdorp aquifer 

E7: Wepener aquifer 

E8a: Well field developments along the route of the existing pipelines: De Hoek Reservoir (Caledon 

pipeline) 

E8b: Well field developments along the route of the existing pipelines: Lieukop Off-take Chamber 

(Botshabelo / Thaba Nchu pipeline) 

SECTION F: Water trading 

F1: Water Trading 



SECTION G: Other options 

G1: Tunnel from Caledon River to the Modder River 

G2: Mine water pumped to Bloemfontein 

G3: Alternative storage in the Caledon River 



SECTION A 

URBAN WATER 

CONSERVATION AND DEMAND 

MANAGEMENT 



A1 & A2 Efficient Use of Water and Loss Management 

1. INTRODUCTION 

As water is a scarce resource, it needs to be used in an efficient and effective manner. Legislation has 

been put in place in South Africa to ensure that this requirement is met. Through WC/WDM, the objective is 

to ensure the optimal use of water and to minimise water wastage. This can be achieved through a number 

of initiatives as listed below, and presented in more detail in this document: 

• Improved efficiency 

– Efficient appliances: (washing machines, toilet cisterns etc) 

– Low flow shower heads 

– Water efficient gardens 

• Loss management 

– Pressure management 

– Retrofitting and removal of wasteful devices 

– Improved management (sectorisation, metering, billing, legislation) 

– Mains replacement 

– Leak detection and repair 

Inefficient usage is attributed to the fact that water is often used for the service derived from it, rather than 

for the water itself. As gardening and toilet flushing (including continuous toilet leaks into the sewerage 

system) represent most of the total domestic demand, they are key focus areas for targeting inefficiencies. 

If a user does not pay for high consumption of water, due to no or inaccurate metering or insufficient credit 

control, that user tends to waste water. Industries and large bulk users would also be target sectors. 

The various WC/WDM options are presented as individual options in this document. However, one or a 

combination of the above options would be appropriate to achieve an objective in a particular area. 

Therefore the respective WC/WDM options should not be considered individually, but rather as a part of an 

overall strategy, to achieve a specific objective. 

2. INTERVENTION DESCRIPTION 

MMM has developed strategies to reduce its unaccounted-for water which is in excess of 40%. There are 

four major themes, each theme covering a number of strategies. 

Network Losses Strategy 

Strategy 1: Development of preventative maintenance strategy 

Strategy 2: Implementation of pressure management systems 

Strategy 3: Embarking on regular communication to capacitate communities 

System Losses Strategy 

Strategy 4: Continuous data analyses of account data 

Strategy 5: Zoning of the MMM water network with zone meters 

Strategy 6: Identify the erven with legal connections without meters 

Strategy 7: Identify wrong meter reading or meter tampering 



Behind-Watermeter Losses Strategy 

Strategy 8: Educate community on how to perform first line inspections 

Strategy 9: Repair any leaks found on site and depending on the pro poor policy 

Strategy 10: Focus on improving the quality of service delivered 

Willingness to Pay Strategy 

Strategy 11: Restrict supply for non payment and excessive use 

Strategy 12: investigate technologies for controlling/ dispensing water consumption. 

MMM is currently struggling with the full implementation of these strategies. One of the reasons behind this 

is that the strategies to address the real and apparent losses are not easy to achieve, as water and 

sanitation services has not been captured in a management information systems. A typical management 

information systems will include information such as consumer billing data, geographical information 

systems (GIS), pressure management information from the pressure reducing valves (PRVs), water flows, 

losses and depths in reservoirs, water balances, information from zone meters and other essential services 

such as customer relations management. 

An estimate of the water use in the Bloemfontein, Botshabelo, and Thaba Nchu areas for the 2006/2007 

financial year is given in the table below (information sourced from the WSDP, 2006/2007). The 

unaccounted for water (UAW) is 30.87 million m 3 /a, which represents 41% of the bulk water supplied to the 

area. 

Detailed breakdown for water use in Bloemfontein, Botshabelo and Thaba Nchu Areas (2006/07) 

Water sector Use (million m 3 /a) 

Bulk Water Supplied 74.95 

Metered domestic/commercial and industrial water use 44.08 

Actual 41% UAW 30.87 

A breakdown of the authorised consumption and water losses within the Bloemfontein/Mangaung area, for 

the 2007/2008 financial year, is given in the table below. The total bulk water supplied to the 

Bloemfontein/Mangaung area was 62 million m 3 /a. The water losses amounted to 23.7 million m 3 /a (or 39% 

of total bulk water supplied to this area). 

For the purposes of this Interim Reconciliation Strategy, the WC/WDM interventions have been divided up 

into three categories, namely: 

Reduction in Bloem Water UAW 

Loss management (MLM) 

Improved efficiency (MLM) 



Unaccounted for Water – Bloemfontein/Mangaung Area (2007/2008 FY) 

Input volume 

62.04 million 

m 3 /a 

Authorised 

consumption 

(estimated) 

38.65 million m 3 /a 

62.3% 

Water losses 

(unaccounted for 

water) 


3. REDUCTION IN BLOEM WATER UAW 

Billed authorised 

consumption 


52.0% 

Unbilled authorised 

consumption 


10.3% 

Apparent losses 

7 million m 3 /a 

30% 

Real losses 


70% 

Billed metered connections 

Billed unmetered connections 

Unbilled metered connections 

(Free Basic Water) 

Unbilled unmetered 

connections (communal taps) 

Unavoidable losses 

Illegal connections 

Metering inaccuracies 

Mains leaks 

Reservoirs overflows 

Service connection leaks 

Revenue 

generating water 


52.0% 

Non-revenue 

generating water 


48.0% 

The bulk water losses for Bloem Water have been calculated as the difference between the volume of 

water abstracted from the various sources and the volume of water sold to consumers. Representatives 

from Bloem Water have indicated that their total overall losses are in the vicinity of 12% of the bulk water 

treated.The table below unpacks the water losses in the bulk water system network of Bloem Water. 

Detailed Breakdown of Water Losses in the Bulk System Network of Bloem Water (BW) 


Financial Year 

2005 2006 2007 2008 2009 

Bulk water supplied from BW's WTWs 53.13 55.27 59.33 62.40 54.82 

Less: Bulk meters to MMM 46.20 49.24 52.05 53.99 49.68 

Less: Supply to other Local Authorities 2.01 2.34 3.01 3.20 3.29 

Bloem Water Conveyance loss downstream of WTP 4.93 3.69 4.27 5.21 1.85 

% water loss downstream of WTP 9.6% 7.0% 7.6% 8.8% 3.6% 

Bloem Water abstraction from Source 54.91 58.01 62.60 65.87 57.13 

Loss in WTW 1.78 2.74 3.25 3.47 2.30 

% water loss in WTW 3.2% 4.7% 5.2% 5.3% 4.0% 

Bloem Water Total water loss 6.71 6.43 7.52 8.68 4.15 

% Total water loss 12.2% 11.1% 12.0% 13.2% 7.3% 

It would appear that conveyances losses are in the order of 7% to 9% per annum. Bloem Water has an 

active database monitoring system, where the water losses of the different supply systems are monitored 

and respective reports are generated. Each of the regional managers within Bloem Water is responsible for 

managing their system water losses. The current levels of water losses do not appear inordinately high. 

A significant portion of this water loss could also be attributed to the regular bursts which occur on the 

Caledon-Bloemfontein pipeline, which is approximately 50 years old. 



The water loss in the WTWs is in the order of 4% to 5% of the source abstracted volume. The most 

significant part of this loss can be attributed to the high sediment loads in the Caledon River, abstracted at 

Welbedacht Dam and treated at Welbedacht WTW. 

For the purposes of this study it was assumed that no significant water saving could be made through 

targeting water losses in the Bloem Water’s supply system. 

4. LOSS MANAGEMENT 

A 2003/2004 estimate of water consumption in the Bloemfontein/Mangaung area, where the UAW (water 

losses) amounted to 23.7 million m 3 /a (or 39% of total bulk water supplied), put the apparent losses at 

7.1 million m 3 /a (30% of the total water loss) and the real losses at 16.6 million m 3 /a (70% of the total water 

loss). The UAW in the Bloemfontein/Mangaung area of supply for the 2007/2008 financial year was 

estimated to be in the region of 23.4 million m 3 /a. For the purposes of this Strategy it was conservatively 

assumed that in 2007/2008 a saving of 14.5 million m 3 /a through water loss management could realistically 

be achieved for the Bloemfontein/Mangaung area of supply. Examples of water loss management 

interventions are given below: 

Pressure management; 

Retrofitting and removal of wasteful devices; 

Improved management (sectorisation, metering, billing, legislation); 

Mains replacement; and 

Leak detection and repair. 

5. IMPROVED EFFICIENCY 

The estimated authorised consumptive water use within the Bloemfontein area is estimated to be 

38.6 million m 3 /a. It has been assumed that with improved efficiency the town of Bloemfontein could reduce 

its authorised consumptive use by 15% or by 5.8 million m 3 /a. It was further assumed that a 15% saving 

could also be achieved on the future water requirements projections. Examples of interventions/actions 

which could lead to an improved efficiency are given below: 

Efficient appliances: (washing machines, toilet cisterns etc); 

Low flow shower heads; and 

Water-wise gardening practices. 

6. SUMMARY OF WC/WDM INTERVENTIONS 

The table below shows the potential savings which could be achieved from the interventions described 

above. Potential savings estimated for the implementation of water use efficiency and water loss 

interventions for the Bloemfontein/Mangaung area of supply have been derived from figures sourced from 

the MLM. For the Botshabelo and Thaba Nchu area of supply, and for the smaller towns the same potential 

savings percentage has been pro-rated to the actual use to give an overall planning estimate of the total 

potential saving that could be achieved. 



Potential Savings that could be Achieved from WC/WDM Interventions 

Type of 

Intervention 

Reduction in 

BW UAW 

Bloemfontein 

/ Mangaung 


% of 

Overall 

Supply 

Botshabelo and 

Thaba Nchu 


Smaller Towns 


Total Based on 

Extrapolation 


0 0 

Water Loss 14.5 22% 2.5 0.73 17.739 

Water Use 

Efficiency 

6 9% 1.35 0.56 7.65 

TOTAL 20.52 3.85 1.03 25.4 

The estimated potential water saving as result of water loss interventions in the study area is 17.7 million 

m 3 /a (16.5 million m 3 /a + 3.22 million m 3 /a). It is estimated that the potential saving through improved water 

use efficiency could be as high as 7.65 million m 3 /a. The following table illustrates the impact of 

implementing a water loss intervention to reduce the current UAW from 41% to 17%. 

Potential Savings that can be Achieved through the Implementation of Water Loss Interventions 

Use (million m 

Water Sector 

3 /a) 

Bloemfontein, Botshabelo and 

Thaba Nchu Areas 

Bulk Water Supply metered to MMM and all WSAs 83.15 

Less: Estimated potential of water loss interventions by 

MLM and WSAs (17.74) 

Estimated target bulk water supply metered to MMM 

and WSAs 65.42 

Less Metered domestic/commercial and industrial 

water use (51) 

Remaining UAW ** 14.41 (or 17%) 

** Note: This is the estimated UAW after the potential water savings have been implemented. 



SECTION B 

AGRICULTURAL WATER 

CONSERVATION AND DEMAND 

MANAGEMENT 




B1. Range of Interventions 

Table 1.1 gives a summary of the extent of the irrigation in the Upper Orange River WMA 2 . The water 

usage for irrigation in the Upper Orange River Catchment are summarised in Table 1.2. 

Table 1.1: Irrigation in the Upper Orange River Catchment 

Description 

Allocation 

(m 3 /ha/year) 

Northern 

Cape 

Area (ha) 

Free State Total 

Kalkfontein WUA 11 000 3 046.30 3 046.30 

Orange-Riet WUA (FS and NC) 11 000 6 714.28 10 257.52 16 971.80 

Proposed Modderrivier and Kalkveld WUA 3 8 130/8 640 12 235.73 12 235.73 

Proposed Vanderkloof WUA (FS and NC) 11 000 14 079.02 7 106.19 21 185.21 

Tierpoort Irrigation Board 9 000 785.71 785.71 

Wittespruit (Egmont Dam) Irrigation Board 6 100 857.00 857.00 

Caledon River upstream Welbedacht Dam ± 4 200 2 342.00 2 342.00 

Caledon River downstream Welbedacht Dam 7 620 2 572.00 2 572.00 

Leeuwrivier/Armenia Irrigation Board 6 100 872.70 872.70 

Total 20 793,30 40 075.15 60 868.45 

2 

Implementation strategy for the use of the 3 000 ha surplus water in the Orange River system allocated to the Free State Province, 

Department of Agriculture, NS No402137/Final, August 08 

3 

Operation Proposal for Modderrivier and Kalkveld WUA, DWAF Bloemfontein, SJ de Wet Report No: W00036/R02/Rv03, August 09 



Table 1.2: Irrigation Water Usage in the Upper Orange River Catchment 

Description 

Allocation 


Potential water use x10 3 m 3 /year 

Northern 

Cape 

Free 

State 

Kalkfontein WUA 11 000 33 509 33 509 

Orange-Riet WUA (FS and NC) 11 000 73 858 112 833 186 691 

Proposed Modderrivier and Kalkveld WUA 8 113 99 271 99 271 

Proposed Vanderkloof WUA (FS and NC) 11 000 154 869 78 168 233 037 

Tierpoort Irrigation Board 9 000 7 071 7 071 

Wittespruit (Egmont Dam) Irrigation Board 6 100 43 133 43 133 

Caledon River upstream Welbedacht Dam ± 4 200 9 836 9 836 

Caledon River downstream Welbedacht Dam 7 620 19 599 19 599 

Leeuwrivier/Armenia Irrigation Board 6 100 5 324 5 324 

Total 

Total 228 727 408 744 637 471 

During the 1990’s the DWAF undertook the “Orange River Replanning Study (ORRS)” to determine the 

status of the availability of water in the Orange River system. This study indicated that sufficient water for 

the irrigation of an additional 12 000 ha was available. This water was reserved for resource poor farmers. 

The water available to all the existing irrigation in the Upper Orange River catchment is fully allocated. In 

order to address the problems with conveyance losses and poor efficiencies Water Management Plans 

were developed for the Orange-Riet WUA and the Kalkfontein WUA. The system losses in the Orange-Riet 

WUA are reported to be ± 20%. 

A number of WC/WDM options for improving the efficiency of irrigation water use have been identified and 

are briefly described below. No quantitative assessments and URVs of these options have previously been 

prepared, and none are presented here. 

2. RIVER RELEASE MANAGEMENT 

In the Caledon River upstream of the Welbedacht Dam no river release management exists because no 

storage is available. The irrigation farmers use off-channel storage dams to store water during the rainy 

season and when there is water flow in the Caledon River. Normally the Caledon River upstream of the 

Welbedacht Dam stops flowing during August or September, depending on the snowfall and rain during 

winter. The towns in the area also use off-channel storage dams for water supply during the time the river 

does not flow. 

In the Caledon River downstream of the Welbedacht Dam the normal flow is released out of the 

Welbedacht Dam. If the inflow is less than 2 m 3 /s then water is stored by Bloem Water and released later 

at a flow rate of 2 m 3 /s for downstream irrigation. Water for irrigation downstream of the Welbedacht dam is 

only available 80% of the time. 



Water stored in the Kalkfontein Dam (Riet River) is released in the Kalkfontein canal for the irrigation 

farmers. No river releases are made. 

The Orange-Riet WUA pump water out of the main canal from the Vanderkloof Dam. This water is 

transferred and used along the Orange-Riet canal and the Riet River settlement near Jacobsdal. Water is 

also released out of the canal system in the Riet River and for irrigation in the lower Modder River up to the 

confluence with the Vaal River. These releases and flow in the Orange-Riet canal are managed with 

regular flow measurement and telemetry. 

The Lower Modder River and Krugersdrift WUA and the Kalkveld WUA selected to become one WUA. This 

report will therefore deal with them as one WUA. The Modderrivier and Kalkveld WUA manage the 

catchment area of the Modder River from the N1 west to about Kimberley. One sub-area is for farmers with 

irrigation out of groundwater. The second sub-area is for irrigation farmers next to the Modder River 

downstream of the Krugersdrift Dam. Water releases out of the Krugersdrift Dam are made for irrigation 

farmers downstream on request of the farmers. Weirs in the river store the water between releases. The 

third sub-area is for the farmers who irrigate with surface water upstream of the Krugersdrift Dam. 

Vanderkloof WUA manage the irrigation farmers next to the Orange River from the Vanderkloof Dam 

downstream close to the confluence with the Vaal River near Douglas. Water is released in the Main canal 

(same as Orange-Riet WUA) and then to the Ramah canal. This water is managed according to the water 

application of the farmers next to the canal. The water released in the Orange River is from the 

hydroelectric plant managed by Eskom. The DWA and Eskom manage these water releases. The 

irrigation farmers next to the river abstract the water directly out of the Orange River for irrigation. 

3. IRRIGATION PRACTICES 

In all the WUAs the on-farm losses occur between the point of abstraction and the field edge. Actual 

irrigation technologies are, for the most part, modern and sophisticated and do not leave much room for 

improvement. It is recognised that many farmers have installed efficient on-farm irrigation methods such as 

pivots, drip, and micro jet. Many farmers are also using the latest technology for irrigation scheduling in 

order to use water efficiently. Water saved by efficient water use is utilised by extending the irrigation area, 

as farmers pay for the full quota. 

4. IRRIGATION CANAL LOSSES 

The following WUAs use canals to convey the water: Orange-Riet, Kalkfontein, and Vanderkloof. The 

Orange-Riet WUA uses the latest technology to monitor (flow meter and telemetry) and manage the flow in 

the canals and the river. The Kalkfontein WUA uses data loggers in the main canal and branch canals to 

monitor the flows. Their overall losses in the canals are calculated to be less than 30 %. 

Whilst little can be done to reduce evaporation losses, proper maintenance and upgrading of ageing water 

distribution infrastructure serving the WUAs, can reduce conveyance losses. The building of a balancing 

dam in the Kalkfontein WUA can help to reduce the distribution losses. 

5. FARM DAM LOSSES 

The Kalkfontein WUA contains a number of private farm dams. It is likely though that the costs associated 

with lining of farm dams will be prohibitively expensive. 



6. CROP SELECTION 

The type of crop selected for a particular area is the most important factor influencing the quantity of water 

required for irrigation. Whilst on the one hand the selection of alternative crop types could reduce water 

requirements, the potential income must also be taken into account. Planting low value “thirsty” crops in 

water scarce areas should be avoided. 

7. CROP DEFICIT IRRIGATION 

This is a technique aimed at providing controlled water stress by periodically irrigating at less than the full 

irrigation demand of the crop. It offers the opportunity to take maximum advantage of the available yield. 

This technique requires meticulous monitoring of soil moisture content, well-designed irrigation systems and 

proper management of pruning and fertilising. 

8. METERING 

The metering of all irrigation releases from source to point of abstraction from canals, and to field 

application is necessary to provide a detailed understanding of utilization and losses. This would assist in 

defining the benefits to be obtained from the various WC/WDM measures, in controlling abstractions and 

usage by irrigators, and in billing for water actually consumed. Very limited metering of irrigation usage 

currently takes place for abstraction out of the river. 

In the Vanderkloof, Modderrivier, and Kalkveld WUA unlawful irrigation takes place. In the Orange-Riet 

WUA a method of satellite images and crop water use figures are used to calculate the water use. If the 

irrigators disagree a water meter must be installed at his cost. Implementing similar methods can reduce 

the unlawful irrigation. 



B2. Agricultural Irrigation Audit Upstream of Maselspoort 

Weir with Improvement for Catchment C52A 


The extent of the irrigation upstream of the Maselspoort Weir to the Rustfontein Dam is unknown and 

therefore the impact on water availability is unknown. This area is not part of any Water User 

Association and is therefore managed by the Department of Water Affairs. The area is included in the 

quaternary catchment of C52A-F. Table 1.1 gives a summary of the extent of the irrigation in the 

Catchment according to the WARMS data. 

Quaternary catchment C52A is upstream of the Rustfontein Dam and includes the Upper- and Lower 

Kromspruit, the Modder River and Gannaspruit. De Wetsdorp is near the start of the Modder River. 

Rustfontein Dam is included in the catchment. 

Quaternary catchment C52B is north of Rustfontein Dam and includes the towns Botshabelo, 

Thaba Nchu, Tweefontein, Groothoek, Springfontein and Gladstone. The Klein Modder River, 

Wildebeesspruit, Sepane and Kgabanyane drain this area to the Modder River between Rustfontein 

Dam and confluence with the Sepane. 

Quaternary catchment C52C Is north of C52B and the Korannaspruit and Steynspruit drain this 

catchment to the Modder River. The small towns in this catchment are Modutung, Spitskop, Merino and 

Rooifontein. 

Quaternary catchment C52D is drained by the Matjiespruit and Koringspruit with the Modder River 

from the Sepane confluence into the Mockes Dam. 

Quaternary catchment C52E is drained by the Klein Osspruit and the Osspruit. The Modder River 

from the Mockes Dam flows into the Maselspoort weir, where water is supplied to the Maselspoort 

waterworks. The quaternary catchment stops downstream of the Maselspoort weir at the Glen 

Agricultural College. 

Quaternary catchment C52F is drained by the Bloemspruit, Rietspruit en Renostersspruit. The 

Bloemspruit drains most of the city Bloemfontein, including water from the Sewage Disposal works. 

Table 1.1: Irrigation in the Quaternary Catchment Areas According to WARMS Data 

Quaternary 

Catchment Area 

Irrigation 

ha 

Registered Volume 

m 3 

Water Use 

m 3 /ha 

C52A 612 5 427 992 8 868 

C52B 421 2 163 920 5 140 

C52C 237 1 095 338 4 616 

C52D 298 

Irrigation only 

17 075 127 

2 118 760 

57 363 

7 118 

C52E 779 3 640 846 4 671 

C52F 1 957 13 713 277 7 008 

Total 4 304 43 116 500 



2. STUDY METHODOLOGY 

The study was done on the bases of quaternary catchments. The quaternary catchment shape files 

were used to create the following: 

Group cultivation land per catchment, with base data from the Agricultural geo-referenced information 

system. 

Farm boundaries per catchment. 

Rivers, streams and dams per catchment. 

By using the rivers and streams layer a 3 km buffer zone on both banks were created. The 

digitised cultivation land layer was reduced to the buffer zone. The digitised cultivation land was further 

reduced by selecting the pivots (round circles) and deselecting cultivation lands bigger than 10 ha. 

This was done because the practice of irrigation without pivots on bigger than 10 ha is highly unlikely. 

The following assumptions were made: 

No water is pumped more than 3 km from a river or stream. Centre pivots are irrigation. 

No irrigation are done on cultivation lands bigger than 10 ha excluding pivots. No dams were taken in 

consideration. 

3. STUDY FINDINGS 

The results are presented on Figures A.1 to A.7 in Annexure A. Table 3.1 gives the extent of the 

irrigation in the Catchments according to the WARMS data, pivot irrigation and other irrigation. 

Table 3.1: Irrigation in the Quaternary Catchment Areas 

Quaternary 

Catchment Area 

WARM 

S 

Irrigation in ha 

Confidence level 

% 

Pivots Other Total Pivots Other 

C52A 612 218 2 951 3 169 90 60 

C52B 421 0 1 087 1 087 90 60 

C52C 237 38 910 948 90 60 

C52D 298 15 1 453 1 468 90 60 

C52E 779 378 3 449 3 827 90 60 

C52F 1 957 649 2 014 2 663 90 60 

Total 4 304 1 298 11 864 13 162 

4. OBSERVATIONS DURING THE STUDY 

The following observations were made during the study: 

There are surface dams in the area and there are a tendency that irrigation are developed around 

these dams. Because of these assumptions, about 5 % of the total irrigation were not captured. 

The confidence level that pivots are irrigation are high. The 90 % confidence is because the 

mapping was done by other persons in 2008. New irrigation development was possible and was 

not measured. 

The confidence level of assumed irrigation are only 60 %. The confidence level of this can be 

higher if satellite images of two or more seasons are available to verify the cultivation patterns. The 

area of assumed irrigation will reduce by about 20 to 40 % when the cultivation patterns are known. 

Some of the WARMS data allocated to a Quaternary Catchment area, projected outside the 

Catchment. This will be rectified with the verification and validation process. 

Dam information also needs to be more accurate. 



5. FARM DAM LOSSES 

The catchment areas contain a number of private farm dams. Losses out of farm dams due to 

evaporation were not taken into account. 

6. NEXT STEPS TO IMPROVE ON THE CONFIDENCE 

In order to further improve on the confidence level of the study a recent Landsat 7 or Spot satellite image 

of the area for two or more seasons are needed. This will be used to: 

1. See if there are new developments. (Satellite image from DWA) 

2. Improve on the split between irrigation and dry land fields. 

3. Site visits to verify 20% of the largest areas. 

4. Summary of above information in a report, tables etc and persent at a meeting. 

As a test to determine the accuracy of the assumptions a satellite image dated 2008-08-16 for 

Catchment C52A was used to identify irrigation more accurately. Out of this the following was 

determined: 

No cultivated land bigger than 10 ha indicate possible irrigation. 

By using the satellite image to select cultivated lands smaller than 10 ha, next to dams and rivers, the 

area of proposed irrigation changed from 2 951 ha to 1 427 ha. 

The satellite image was for a winter season, where this is a summer planting region and a January or 

February image will give a better indication. 

This 52 % reduction in proposed irrigation show the importance of the satellite image test to the data. 

7. WATER USE BY THE IRRIGATION 

The type of crop planted in a particular area is the most important factor influencing the quantity of water 

required for irrigation. In order to estimate the water use by the irrigation the type of crops need to be 

established. This can only be done with a visit to the site. The other important issue is whether they plant 

one or two crops in a year. Out of the WARMS data the water use calculated to be between 4 616 

m3/ha/year to 8 868 m3/ha/year. If the crops are known PLANWAT can be used to calculate the crop 

water requirement per Quaternary Catchment Area. 

Whilst on the one hand the selection of alternative crop types could reduce water requirements, the 

potential income must also be taken into account. Planting low value “thirsty” crops in water scarce 

areas should be avoided. 

8. IMPROVEMENT FOR CATCHMENT C52A 

A recent Spot 5 satellite image was obtained from the Department of Water Affairs. Unfortunately the 

date of the image is not known and therefore the season is not known. 

8.1 See i f there are New Developments (Satellite Image From DWA) 

No new developments were observed on the Satellite image between the new image and the one dated 

2008-08-16. 

8.2 Improve on the Split Between Irrigation and Dry Land Fields 

The satellite image for Catchment C52A was used to split the irrigation and dry land fields. 

All fields in Catchment C52A that shown green was digitised and the area was determined. This 

area exclude the pivot irrigation. 



Each of the 199 fields identified were enlarged to identify possible irrigation. All the 

irrigation fields, excluding pivots, identified were smaller than 10 ha. 

Because only one satellite image was supplied, double cropping could not be determined. 

The date and season of the satellite image is not known and therefore crop water use could not be 

determined. 

Table 8.1: Irrigation in the Quaternary Catchment C52A 

Quaternary 

Irrigation in ha Confidence Level % 

Catchment 

Area 

WARMS Pivots Other Total Pivots Other 

First estimate 612 218 2 951 3 169 90 60 

Satellite Image 2008-08-16 612 140 1 427 1 567 90 70 

Satellite Image supplied by DWA 

all cultivated fields 

612 140 1 654 1 794 90 75 

Satellite Image supplied by DWA 

selected as irrigation 

612 140 466 606 90 90 

8.3 Conclusion 

The 78 ha of pivot irrigation that was not planted can still be seen as irrigation. A next season will 

improve the estimate of the irrigation. The verification and validation process in the Upper Orange River 

will be done in the next two years and beter WARMS information should be available after the process is 

complete. 



SECTION C 

SURFACE WATER 

INTERVENTIONS ON THE 

ORANGE RIVER 



C1. Utilising Surplus Capacity in the Orange River by 

Pumping to Knellpoort Dam from Gariep Dam 

1. SCHEME DESCRIPTION 

The information presented in this section has been derived from the Orange River Development Project 

Replanning Study (ORP study), dated May 1998. The aforementioned study considered obtaining surplus 

volume in the Gariep dam via the following interventions: 

Using dead storage by altering the operating rules to allow the water below the existing canal 

(bottom) inlets to be used for the downstream users with no additional infrastructure being required; 

or 

Raising Gariep Dam with options proposed for 5 m and 10 m raising respectively. 

The most feasible (preferred) of the above options was not determined as part of this study. For the 

purposes of this study, it is assumed that surplus water will be available from the Gariep Dam where it will 

be abstracted and pumped to the Knellpoort Dam or any alternative destination. An “Orange River water 

charge” (to be determined) will then be applied to the Purchaser of this surplus water. For purposes of first 

order costing, it is assumed that surplus water to be made available for Bloemfontein and surrounding 

towns is 10 million m 3 /a at a cost of R 2.00 per m 3 . 

It is envisaged that water will be pumped (approximately 150 km) from the Gariep Dam to the Knellpoort 

Dam via a 600 mm diameter pump-main, from where it will be transferred via the Novo Transfer Scheme 

and Modder River to the Rustfontein Dam for supply to Bloemfontein and surrounding towns (see 

Figure C1). Currently the Novo Transfer Scheme has a pump station capacity of 1.5 m 3 /s with the 

immediate potential to be upgraded to 2.4 m 3 /s, and the delivery main has a design capacity of 2.4 m 3 /s. 

The capacity of this pump station and associated delivery main to Rustfontein Dam (via the Modder River 

system) can be further increased, which will ultimately depend on the volume of water to be transferred 

from Gariep Dam to Knellpoort dam. 



Figure C1: Additional Supply from Gariep Dam 



2. SCHEME YIELD 

For the purposes of this study, it is assumed that a yield of 10 million m 3 /a of the total available yield will be 

made abstracted from Gariep Dam for Bloemfontein and surrounding towns. The ORP study proposed that 

the total available yield as a result of implementing one the various interventions would amount to: 

Using dead storage: Additional yield of 27 million m 3 /a; 

Raising Gariep Dam by 5 m: Additional yield of 316 million m 3 /a; or 

Raising Gariep Dam by 10 m: Additional yield of 635 million m 3 /a. 

3. UNIT REFERENCE VALUE 

A first order estimate of financial costs for the surface water option is presented below: 

Surplus Water Costs 

(Orange River Water) 

Charge per m 3 for Orange River Water R 2.00 (Charge per m 3 for Orange River Water) 

Discount Rate 

4% 

Discount Rate 

6% 

Discount Rate 

8% 

Total capital cost (R million) R 859 R 859 R 859 

Annual operating cost (R mill /annum) R 62 R 62 R 62 

NPV Cost (R million) R 2 058 R 1 674 R 1 431 

Unit Reference Value (R/m 3 ) R 5.25 R 6.01 R 6.85 

Note: The costs and URVs are based on the following assumptions: 

o The base date for the above estimate is July 2009. 

o Costs associated with the “Infrastructure Link to Knellpoort” is based on a 150 km pump 

system (pump station and rising main) capable of delivering 10 million m 3 /a. 

o Costs associated with the upgrade of the Novo Transfer Scheme have been excluded. 

o The above costs do not include costs associated with the land acquisition or location. 

o Refurbishment Costs have not been considered. 

4. POTENTIAL IMPACTS 

The main environmental impact of this intervention relates to the construction of the pipeline which will 

traverse shrubland (Low and Rabelo, 1996), cultivated land, and grassland. Furthermore, conservation 

areas, wetlands, and a number of small roads will also need to be taken into account when selecting a 

pipeline route. 

In addition to the abovementioned impacts, the following issues have been identified: 

The fish population in the dam may become stressed if the dead storage is used. 

Capital investment for bulk delivery infrastructure from Gariep Dam to Knellpoort Dam is high. As 

such this surface water intervention may not be financially feasible to cater for Bloemfontein and 

surrounding towns. 

No fatal flaws were identified. 




Pumping to Knellpoort Dam from Vanderkloof Dam 

1. OPTION DESCRIPTION 

The information presented in this section has been derived from the Orange River Development Project 

Replanning Study (ORP study), dated May 1998. The aforementioned study considered surplus volume in 

the Vanderkloof dam by utilising the dead storage by altering the operating rules to allow the water below 

the existing canal (bottom) inlets to be used for the downstream users with no additional infrastructure 

being required. The ORP study identified approximately 810 million m 3 of surplus water below the minimum 

operating level (existing level of the outlets to the irrigation systems) that can be utilised for irrigation and 

domestic purposes. If the above surplus volume is to service the Orange River supply area only, then the 

dead storage at Vanderkloof should be utilised either through the provision of pumps to lift the water into 

the irrigation canals or by altering the operating rules to allow the water below the existing canal (bottom) 

inlets to be used for the downstream users without any supply through the Vanderkloof Canal. The first 

proposal of a pump system will however impact on the energy that can be generated by the hydropower 

plant at the dam. 

For purposes of this study, it is assumed that surplus water will be available from the Vanderkloof Dam 

where it will be abstracted and pumped to the Knellpoort Dam or any alternative destination. An “Orange 

River water charge” (to be determined) will then be applied to Purchaser of this surplus water. For purposes 

of first order costing, it is assumed that surplus water to be made available for Bloemfontein and surrounds 

is 10 million m 3 /a at a cost of R 2.00 per m 3 . 

It is envisaged that water will be pumped (approximately 200 km) from the Vanderkloof Dam to the 

Knellpoort Dam via a 600 mm diameter pump-main, from where it will be transferred via the Novo Transfer 

Scheme and Modder River to the Rustfontein Dam for supply to Bloemfontein and surrounding towns. 

Currently the Novo Transfer Scheme has a pump station capacity of 1.5 m 3 /s with the immediate potential 

to be upgraded to 2.4 m 3 /s, and the delivery main has a design capacity of 2.4 m 3 /s. The capacity of this 

pump station and associated delivery main to Rustfontein Dam (via the Modder River system) can be 

further increased, which will ultimately depend on the volume of water to be transferred from Vanderkloof 

Dam to Knellpoort dam (Figure C2). 



Figure C2: Additional Supply from Vanderkloof Dam 




For the purposes of this study, it is assumed that a yield of 10 million m 3 /a of the total available yield will be 

made available from Vanderkloof Dam for Bloemfontein and surrounds. The ORP study proposed that the 

total available yield as a result of utilising the dead storage would amount to 222 million m 3 /a. 

If the above scheme is realised, then it is proposed that adequate yield be allocated for Bloemfontein and 

surrounding towns to meet their 20 to 30 year water requirements. 






Discount Rate 

4% 

Discount Rate 

6% 

Discount Rate 

8% 

Total capital cost (R million) R 1 007 R 1 007 R 1 007 

Annual operating cost (R mill /annum) R 44.4 R 44.4 R 44.4 

NPV Cost (R million) R 1 848 R 1 561 R 1 376 




o Costs associated “Infrastructure Link to Knellpoort” is based on a 200 km pump system (pump 

station and rising main) capable of delivering 10 million m 3 . 





The Vanderkloof Dam is predominantly situated amongst land cover of shrubland (Low and Rabelo, 1996), 

the proposed pipeline route to Knellpoort Dam will follow shrubland, and some cultivated land. The 

proposed pipeline will not traverse or be able to follow any roads from Vanderkloof Dam. The proposed 

pipeline may traverse the Rolfontein conservation area from the dam. The crossing of wetlands will also 

have to be assessed and mitigated where necessary. 

Specific weaknesses of the scheme include: 

A negative impact for periods when hydro-power cannot be generated due to water shortages. 

Capital investment for bulk delivery infrastructure from Vanderkloof Dam to Knellpoort Dam is high, 

and may not be financially feasible to cater for Bloemfontein and surrounding towns. 

No fatal flaws have been identified. 




Pumping to Knellpoort Dam from Bosberg / Boskraai Dam 


This scheme comprises of the proposed Bosberg Dam on the Orange River, together with another dam of 

similar height on the Kraai River (Figure C3). The information presented in this section has been derived 

from the ORP study, dated May 1998. 

1.1 BOSBERG DAM 

The ORP study proposed the Bosberg Dam be located along the Orange River, downstream of the 

confluent of the Kraai River. The dam comprises of a main dam wall of variable heights between a FSL of 1 

370 m and 1 400 m. For purposes of this report, the main dam wall has been taken as 57 m high (FSL = 1 

385 m) to the full supply level, and a saddle wall (partition wall) on the southern bank of the Orange River. 

Any storage above the proposed full supply level would potentially result in spillage over the watershed to 

the Kraai River basin, requiring a saddle dam known as the Boskraai dam. Further details of the Boskraai 

dam shall be discussed in more detail in the following section. 

The Bosberg dam was originally proposed in ORP study to transfer water to the Vaal River system and to 

support the Gariep and Vanderkloof dams when their maximum operational level is reached. Smaller 

volumes along the Orange River can also be anticipated as a result of Polihali Dam (Lesotho Highlands 

Water Project), or as a result of surplus water from the Orange River System. The ORP study also noted 

that the scheme is most cost effective for transfer volumes greater than 20 m 3 /s. 

1.2 BOSKRAAI DAM 

The Boskraai Dam actually consists of a Bosberg Dam of higher than 57 m on the Orange River, together 

with a dam of similar height on the Kraai River. Water would spill from one storage basin, creating a joint 

reservoir basis when the water depth behind both dams exceeds this level. This option includes the benefit 

of utilising runoff from the Kraai River at the same time. Although the site allows for higher dams to be built, 

a maximum water depth of about 75 m (FSL = 1 372 m) was assumed for Boskraai, as the backwater may 

extend into Lesotho territory at higher levels. 



Figure C2: Surplus Capacity in the Orange River by Pumping to Knellpoort Dam from Bosberg / Boskraai Dam 



The Bosberg and Boskraai option is seen as a more plausible alternative to the “Raising of Gariep dam” as 

this option will store water further upstream in the catchment, where the evaporation is less and the 

possibility of providing an economically viable transfer to the Vaal system is higher. 

It is envisaged that water will be pumped (approximately 100 km) from the Bosberg/Boskraai Dam to the 

Knellpoort Dam via a 600 mm diameter pump-main, from where it will be transferred via the Novo Transfer 

Scheme and Modder River to the Rustfontein Dam for supply to Bloemfontein and surrounding towns. 

Currently the Novo Transfer Scheme has a pump station capacity of 1.5 m 3 /s with the immediate potential 

to be upgraded to 2.4 m 3 /s, and the delivery main has a design capacity of 2.4 m 3 /s. The capacity of this 

pump station and associated delivery main to Rustfontein Dam (via the Modder River system) can be 

further increased, which will ultimately depend on the volume of water to be transferred from the proposed 

Bosberg/Boskraai Dam to Knellpoort Dam. 

2. OPTION YIELD 

For the purposes of this study, it is assumed that a yield of a yield of 10 million m 3 /a of the total available 

yield will be made abstracted from Bosberg/Boskraai Dam for Bloemfontein and surrounding towns. The 

ORP study proposed that the total available yield as a result of implementing one the various interventions 

would amount to: 

Bosberg Dam: Additional yield of 3,652 million m 3 /a; or 

Bosberg and Boskraai Dam: Additional yield of 6,508 million m 3 /a. 






Discount Rate 

4% 

Discount Rate 

6% 

Discount Rate 

8% 

Total capital cost (R million) R 375 R 375 R 375 

Annual operating cost (R mill /annum) R 33 R 33 R 33 

NPV Cost (R million) R 996 R 780 R 676 


Note The costs and URVs are based on the following assumptions: 


o Costs associated “Infrastructure Link to Knellpoort” is based on a 100 km pump system (pump 

station and rising main) capable of delivering 10 million m 3 /a. 







The Boskraai Dam is situated in grassland type of land cover (Low and Rabelo, 1996), and the proposed 

pipeline will follow through this. The proposed pipeline can follow a secondary road from the Boskraai Dam 

to the Knellpoort Dam. This pipeline will also potentially traverse the conservation area named, Aasvoel 

Bewaringsbied. The crossing of wetlands will also have to be assessed and mitigated where necessary. 

The following issues have been identified: 

The inevitable loss of the use of the land that will be inundated and any associated ecology. 

The capital costs of this scheme are high. 


5. KEY ISSUES 

Strengths: 

The scheme can be integrated with the Lower Kraai River. 

Evaporation within this catchment is lower than downstream catchments, making this large 

augmentation option more economically viable transfer to the Vaal system. 

Weaknesses: 

Capital investment for the dam is high, and the primary driver for implementation of this scheme will 

be irrigation use. 

Capital investment for bulk delivery infrastructure from Bosberg/Boskraai Dam to Knellpoort Dam is 

relatively high, and the financial feasibility of this investment warrants further investigation. 

Polihali Dam (Lesotho Highlands) will impact the flows along the Orange River. 

Potential inundation of established agricultural land downstream will also have to be investigated 

further. 



C4. Modifications to Welbedacht Dam: Extend Scour 

Operations & Lower Outlets 


This option considers the potential to increase the available yield from Welbedacht dam by reducing the 

existing dead storage as a result of siltation of the dam. 

1.1 Welbedacht Dam 

The Welbedacht Dam is situated on the Caledon River, where water from the Caledon River is treated at 

the Welbedacht WTW and then supplied to urban users in Bloemfontein, Botshabelo, Dewetsdorp, and 

various other smaller users as well as irrigators downstream in the Caledon River. Water is transferred to 

Bloemfontein via the Caledon-Bloemfontein pipeline which was commissioned in 1974 to supply potable 

water from the Welbedacht Dam on the Caledon River to Bloemfontein. 

The Welbedacht WTW is situated just downstream of Welbedacht Dam and has a capacity of 145 Ml/day. 

This water is pumped after purification via a 6.5 km pressure pipeline and a 106 km gravity pipeline to 

Bloemfontein. The average capacity of the pipeline is 1.7 m 3 /s and the maximum capacity 1.85 m 3 /s. This 

pipeline is some 40 years old and its condition is deteriorating. 

The Caledon River is characterised by severe sedimentation problems, clearly demonstrated by the loss of 

storage capacity of the Welbedacht Dam which has decreased from 114 million m 3 to about 15 million m 3 

when last estimated in 1994. Due to the decreasing yield of the Welbedacht Dam, the DWA supplemented 

the yield of the Welbedacht Dam by constructing the Knellpoort off-channel storage dam on the Rietspruit, a 

tributary of the Caledon River. As a result of minimal storage capacity in Welbedacht Dam, the Tienfontein 

pumps must operate at a high reliability on a run of river basis to supply Knellpoort Dam. The current 

pumps have a total discharge of approximately 2.5 m 3 /s (design 3 m 3 /s) and have experienced high 

maintenance costs as a result of fine debris and sediment which reach the pumps. 

1.2 Alternative Scenarios for Welbedacht Dam 

The following alternatives for maintaining and/or increasing the available yield from the Welbedacht dam to 

Bloemfontein and surrounds via the Bloemfontein-Caledon pipeline have been identified: 

Alternative 1: Extended Scour Operation at Welbedacht Dam. This would be required to maintain 

the existing yield of Welbedacht Dam. 

Alternative 2: Lowered Gates at Welbedacht Dam. This could potentially increase the yield of 

Welbedacht Dam. 




The increase in yield for this intervention has not been determined. Detailed sediment modelling will have to 

be undertaken to ascertain the potential increase in yield. The determination of this additional yield is part of 

a more detailed study to be undertaken by Bloem Water. 


Due to the yield not being available, a URV was not calculated. 



C5. Modifications to Caledon-Modder System 


This option considers the potential to abstract additional yield from the Caledon River for transfer to 

Bloemfontein via the Novo Transfer Scheme. The Novo Transfer Scheme is owned and operated by Bloem 

Water and became operational in 1998. The scheme includes the following infrastructure: 

Tienfontein pump station on the banks of the Caledon River; 

A pipeline and canal from Tienfontein pump station to the Knellpoort Dam; 

The Knellpoort Dam; 

The Novo pump station on the northern side of the Knellpoort Dam to transfer water from the dam to 

the Modder River (current installed capacity is approximately 1.5 m 3 /s); 

The Novo pipeline (design capacity of 2.4 m 3 /s) that runs 20 km from the pump station to the 

headwaters of the Modder River on Dewetskrom Farm; and 

From the outfall of the Novo pipeline water flows down the Modder River to Rustfontein Dam, a 

distance of ± 50 km. Water stored in Rustfontein Dam is treated at the Rustfontein Treatment Works 

and pumped to Botshabelo/Thaba Nchu or Bloemfontein/Mangaung. 

The yield of the Caledon-Modder System can be increased by one, many or a combination of interventions 

(Figure C3). These are listed below: 

a) Increase capacity of Novo Pump Station 

b) The raising of Knellpoort Dam 

c) Increasing the Capacity of Tienfontein (TFT) Pump Station 

d) Implementing a pump station and pipeline between Welbedacht Dam and Knellpoort Dam 

e) Construction of a new canal to carry water from the Caledon River close to Jammersdrift Weir, 

upstream of Tienfontein Pump Station, to Knellpoort Dam. 

f) A combination of the abovementioned interventions 



Figure C3: Modifications to the Caledon-Modder System 



For the existing situation (assuming agricultural water requirement upstream and downstream of 

Welbedacht Dam, an estimate for environmental water requirements and an allocation of 200 ha for 

resource poor farmers), the initial constraint on the yield of the Caledon Modder System is the capacity of 

Novo Pump Station. Thereafter the constraint is either the capacity of Knellpoort Dam or the capacity of 

Tienfontein Pump Station. The capacity of Novo Pump Station would also have to be further increased 

should additional storage capacity or inflow capacity be provided. 


The potential yields and estimated costs of the interventions are discussed below. . It is important to note 

that if the continued and on-going sedimentation of Welbedacht Dam is not addressed through a longer 

scouring/flushing duration of the dam, then any increase in the capacity of Tienfontein Pump Station may 

not lead to an increased system yield due to the operational problems of managing silt at Tienfontein Pump 

Station. Other relevant factors are: 

a) Novo Pump Station: The civil structure of Novo Pump Station was initially constructed to house 

pumps with a capacity of 4.8 m 3 /s. The current installed capacity of Novo Pump Station is 1.5 m 3 /s. 

The pipeline from Novo pump station to the head waters of the Modder River has a capacity of 

2.4 m 3 /s. If the capacity of Novo Pump Station is increased beyond 2.4 m 3 /s, an additional pipeline 

from Novo Pump Station would have to be constructed. 

b) Knellpoort Dam: The possibility of raising Knellpoort Dam was investigated. An analysis of the 

historical firm yields showed that raising the dam by 1 to 4 m would not increase the yield of the 

system significantly. This option was not considered further. 

c) Tienfontein Pump Station: The existing civil structure of Tienfontein Pump Station consists of 7 

pump bays of which 4 of the bays currently have pump sets each with an installed capacity of 1 m 3 /s. 

There are currently 3 vacant bays. The design capacity of the pump station is currently 3 m 3 /s with 1 

m 3 /s standby capacity. 

d) Welbedacht Pump Station: This is a possible future intervention which would pump directly from 

Welbedacht Dam to Knellpoort Dam. 

e) New Canal :A diversion weir and canal to transfer water from the Caledon River upstream of the 

Tienfontein Pump Station to Knellpoort Dam by gravity has been proposed in the past. This proposal 

was made before the construction of Welbedacht Dam and other infrastructure downstream. It is 

unlikely that a scheme of this nature could be implemented now due to the existing infrastructure 

development downstream, the environmental water requirements, potential upstream development, 

and international obligations with Lesotho. The development of this scheme would reduce the yield of 

existing schemes downstream of Jammersdrift Weir. Consequently, it was not considered further. 

(See also Section G1: Tunnel from Caledon) 

The phasing and implementation of the pumping infrastructure comprising the Novo Transfer Scheme is an 

important consideration. Whilst it may not make sense to increase the pumping capacities of the 

Tienfontein and Novo Pump Stations incrementally, it must be understood that in terms of the yield 

determinations “yield bottlenecks” may occur as a result of pumping/conveyance infrastructure capacity 

constraints. 

The study undertaken by Bloem Water to investigate the extension of the capacity of the Novo Transfer 

Scheme identified a number of Interventions which should be implemented. 

An Intervention is seen as an action or group of actions that are applied to the Novo Transfer Scheme at a 

set time to enhance the transfer capacity of the system. Each Intervention is a phased approach to be 

implemented according to timeframes as determined and discussed under the following sections. 



3.1 Tienfontein and Novo Pump Stations 

The interventions as proposed by the Bloem Water Report, and numbered differently from the list appearing 

earlier in this section, are outlined below: 

Intervention 1: This intervention entails operating all 4 pumps at the existing Tienfontein Pump Station 

simultaneously (i.e. with no standby capacity). Should water levels in the Caledon River permit, the full 

utilisation of the existing pump station capacity would enable 3.5 m 3 /s to 4 m 3 /s to be transferred to 

Knellpoort Dam via Tienfontein Pump Station. 

Intervention 2: This intervention entails the installation of three new high capacity pump sets at Tienfontein 

pump station, each with a capacity of 2 m 3 /s. In addition, a duplicate steel rising main is required from the 

Tienfontein pump station to the sand traps with surge chamber and additional sand traps to be constructed. 

To make full use of the 2.4 m 3 /s capacity of the existing steel rising main between Knellpoort Dam and the 

upper reaches of the Modder River, it is recommended that a pumpset with a capacity of 1.6 m 3 /s capacity, 

similar to existing pumpsets, be installed at Novo Pump Station. The newly installed pump set, operating in 

parallel with one of the existing pump sets could deliver ± 2.3 m 3 /s. The electricity supply to Novo Pump 

Station would also need to be upgraded. 

Intervention 3: This intervention entails the installation of a second new high capacity pump set at Novo 

pump station to transfer an additional 1.67 m 3 /s via a new parallel installed steel rising main from the Novo 

pump station through to the upper reaches of the Modder River. 

Table 3.1 below summarises the Interventions together with the required pumping infrastructure capacities. 

Table 3.1: Caledon Bloemfontein transfer scheme interventions 

Intervention 

Tienfontein P/S Capacity 

(m 3 /s) 

Novo P/S 

(m 3 /s) 

Novo / Modder Rising 

Main (m 3 /s) 

Intervention 1 

4 

(by utilising standby capacity) 

1.5 2.4 

Intervention 2 7 2.4 2.4 

Intervention 3 7 4.8 4.8 

Whilst the interventions described above target increasing the capacity of the existing supply infrastructure 

they are not necessarily the best interventions to implement to increase the available yield of the system 

and do also not address the underlying risks associated with sedimentation. Table 3.2 below shows the 

incremental yield (determined from the water resources yield model) associated with each intervention, and 

highlights risk/concerns from a longer term reconciliation of supply and requirement point of view. 



Table 3.2: Incremental Yield Associated with Each Intervention Listed in Table 3.1 

Intervention 

Incremental Yield 

(million m 3 

/a) 

Intervention 1 4.4 

Intervention 2 

11.5 (15.9 

including the yield 

from Intervention 1 ) 

Intervention 3 4.4 

Comments 

Intervention 1 is not seen as a permanent solution, as given 

the historical sediment related problems experienced at 

Tienfontein Pump Station and the very high operating and 

maintenance costs utilising the standby capacity may be 

impractical to do on a sustained basis. This also poses 

additional risks in terms of breakdowns and maintenance. 

The full implementation of Intervention 2 should be subject to 

the scouring/flushing limitations on Welbedacht Dam being 

addressed and a workable solution found. If these problems 

are not addressed the siltation problems at Tienfontein Pump 

Station may limit the usage of the increased capacity 

This intervention did not increase the yield any more than 

Intervention 1 did and was not considered further. 

Tienfontein Pump station currently has a design capacity of 3 m 3 /s, but due to the sedimentation related 

problem and high maintenance requirements delivers on average approximately 2.5 m 3 /s. It is proposed 

that as an interim solution those two additional (1 m 3 /s) pump sets at Tienfontein Pump Station be 

implemented. The first pumpset should be utilised to increase the design capacity of the pump station to 

4 m 3 /s and the second pumpset to provide additional standby capacity. This would provide an additional 

yield of approximately 4.4 million m 3 /a. With an increase in the standby capacity (proposed 50% of design 

capacity), maintenance of pumps could be more easily facilitated without impacting on the operating 

capacity of the pump station. 

3.2 Scouring/flushing of Welbedacht Dam 

Due to the high turbidity of the raw water, especially during flood events it is not possible to operate 

Welbedacht WTW at full capacity throughout the year. A discussion with the operator of the WTW 

suggested that the WTW could operate at full capacity (145 Ml/d) in winter, but only managed an output of 

between 90 and 100 Ml/d in summer when the silt load in the river was higher. The yield of the system 

could therefore potentially increase if the WTW was operated a full capacity all year round. 

The possibility to supply raw water to Welbedacht WTW from a source other than the Welbedacht Dam was 

recently investigated by Bloem Water and the DWA. The report, which was entitled “Investigation into the 

Condition of the Caledon River at Welbedacht Dam” (SSI, 2011) investigated the sedimentation problems 

and potential solutions in more detail. This report contained the following two recommendations: 

1) Conduct a detailed investigation and cost estimate to modify the Tienfontein Pump Station to such 

an extent that the pump station can operate efficiently under the current in-take conditions 

2) Conduct a detailed feasibility study to improve the storage capacity of Welbedacht Dam, through 

the scouring/flushing of Welbedacht Dam. 

The report found that Welbedacht Dam could be scoured for a period of 4 days continuously during times of 

floods in the Caledon River if either: 

1) an off-channel storage dam was constructed to supply Welbedacht WTW, or 

2) a supply pipeline was laid between Knellpoort Dam and Welbedacht WTW. 

The yield analysis undertaken found that by operating Welbedacht WTW at 145 Ml/d throughout the year 

and by increasing the storage capacity of Welbedacht Dam to approximately 13 million m 3 , the incremental 

historical firm yield of the system could be increased by 7.06 million m 3 /a and 1.89 million m 3 /a respectively. 

The scouring operation with alternative feed to Welbedacht WTW could therefore increase the historical 



firm yield of the system by approximately 9 million m 3 /a. The capital cost of the two alternatives together 

with the associated URVs as given in the report on the investigation (SSI 2011) is shown in Table 7-10 

below. 

Table 3.3: Capital Costs and URVs Associated with the Scouring / flushing of Welbedacht Dam 

Intervention 

Off channel storage dam to supply 

Welbedacht WTW 

Raw Water Supply from Knellpoort 

Dam to Welbedacht WTW 

3.3 Welbedacht Pump Station 

Incremental Yield 

(Million m 3 /a) 

Capital Cost 

(R Million) 

URV 

(R/m 3 ) 

9 270 2.12 

9 297 2.33 

In addition to the interventions proposed to increase the capacity of the Novo Transfer Scheme, this 

intervention entails the construction of a new pump station at Welbedacht Dam with a capacity of 

approximately 2 m 3 /s (although this could be increased to obtain additional system yield) to pump water to 

Knellpoort Dam. There is potential synergy between this intervention and the interventions described in 

Section 3.2 above. Should a pipeline be constructed between Knellpoort Dam and Welbedacht WTW to 

facilitate the scouring of Welbedacht Dam by providing a continuous supply of water to Welbedacht WTW, 

then this pipeline could be used in reverse as a rising main and pump water from Welbedacht Dam to 

augment the supply to Knellpoort Dam. The pipeline could only be used when Welbedacht Dam was not 

being scoured. For the purposes of the yield calculations, it was assumed that the Welbedacht Dam would 

not be scoured for a duration of more than 4 days and not more than 4 to 5 times per year. The indicative 

yields, capital costs, operating costs and URVs associated with this intervention are given in Table 3.4 

below. The URV calculations have been worked out firstly assuming a new pipeline would need to be 

implemented between Welbedacht Dam and Knellpoort Dam, and then assuming that a pipeline had 

already been constructed to facilitate the scouring of Welbedacht Dam (and that the pipeline would then be 

used as a bi-directional pipeline). The URV of the integrated solution was also calculated. 

Table 3.4: Welbedacht Pump Station Interventions 

Intervention 

Welbedacht P/S with raw 

water pipeline to Knellpoort 

Dam. 

Integrated Solution 

(Welbedacht P/S and 

scouring of Welbedacht 

Dam) 

Incremental 

Yield 

(Million m 3 /a) 

Capital Cost 

(R Million) 

Operating 

Cost 

(R Million) 

URV at 

4% 

(R/m 3 ) 

URV at 

4% 

(R/m 3 ) 


URV at 

4% 

(R/m 3 ) 

20 374 9.4 1.37 1.70 2.07 

27 374 7.1 0.93 1.17 1.44


C6. Polihali Dam – Lesotho Highlands Phase 2 


The information provided for this development option has been extracted from the “Consulting Services for 

the Feasibility Study for Phase II”, Main Report (version 4) for the Lesotho Highlands Water Project, dated 

February 2009 (Report No: LHWC 001/224/2007 and P RSA D000/00/7007). This report will be referred to 

as the Phase 2 Report. 

The development of the Lesotho Highlands Water Project (LHWP) was agreed between South Africa and 

Lesotho in the Lesotho Highlands Water Project Treaty signed in October 1986 (hereafter referred to as the 

Treaty). The project would comprise a number of Phases. However, the Treaty only committed both parties 

to implement Phase I. The Treaty provided for further Phases to be developed to transfer up to a maximum 

of 70 m 3 /s (or 2 208 Mm 3 /a) from the Highlands of Lesotho (Senqu/Orange River) to the Vaal River system 

in South Africa. 

Phase I of the project comprised two sub-phases, namely Phases IA and IB. Phase IA of the project 

comprises the 185 m high double curvature concrete arch dam at Katse. Water is transferred under gravity 

via the 44 km long, 4.35 m internal diameter, concrete lined Transfer Tunnel to the Muela Hydro Power 

Station which discharges into the 55 m high Muela concrete arch dam before flowing through the 38 km 

long Delivery Tunnel to the Ash River outfall in South Africa. The water then flows down the Ash and Wilge 

Rivers into Vaal Dam. 

Phase IB comprises the 145 m high concrete faced rockfill dam at Mohale. A 32 km long concrete lined 

gravity tunnel connects Mohale Dam to Katse Dam from where the water also flows through the Transfer 

Tunnel constructed under Phase IA to the Muela Hydro Power Station, and is finally discharged into the 

Ash River. An additional component of Phase I was the 19 m high Matsoku diversion weir transferring water 

to Katse reservoir. The published Nominal Annual Yield (NAY) of Phase I is 24.7 m 3 /sec or 780 million 

m 3 /annum. 

The works proposed for Phase II would comprise Polihali Dam (wall height of 163.5 m) and a gravity tunnel 

to Katse Dam. Water from the Polihali Dam would then be delivered from Katse Dam via the existing 

Transfer Tunnel to Muela Hydro Power Station and thence via the existing Delivery Tunnel to the Ash River. 

The incremental yield of Phase II would be 14.75 m 3 /s or 465 million m 3 /a. The Phase II Report indicates 

that Phase II would be commissioned by January 2020. The report anticipates that Phase 3 would only be 

required by 2054. 

The option of making additional early transfers from the LHWP needs to be considered for Bloemfontein 

and surrounding towns. Possible options for transfers in excess of the proposed delivery schedule to South 

Africa (Scenario D shown in the figure below) include additional releases into a tributary of the Caledon 

River to temporarily augment supplies to Maseru, Bloemfontein and other urban towns within the catchment 

area. This supply could delay additional capital expenditure on improvements to the existing bulk water 

infrastructure supplying Maseru and Bloemfontein. The implications of making additional early transfers in 

excess of those provided for in the Agreement between Lesotho and South Africa are uncertain and would 

need to be resolved from a National perspective before this option could be considered. 

It is proposed that water from the LHWP would be released into one of the tributaries of the Caledon River, 

probably at the existing release structure on the Little Caledon River. Water released into the Caledon River 

would be abstracted at Tienfontein Pump Station and delivered to Knellpoort Dam, from where it would be 

transferred via the Novo Transfer Scheme and Modder River to the Rustfontein Dam to augment the supply 



to Bloemfontein and the surrounding towns. Currently the Novo Transfer Scheme has a pump station 

capacity of 1.5 m 3 /s which could be upgraded to 2.4 m 3 /s by the provision of additional pumps. This 

capacity could be doubled by duplicating the Novo Pump Station and pipeline. 


The graph below shows the agreed Delivery Schedule (Scenario D) for the transfer of water from Phase II 

to Vaal Dam as per Treaty, and also shows the water that could be made available by LHWP Phase II for 

transfer to Vaal Dam to meet the Delivery Schedule. 

The following options are proposed for making additional early transfers from the LHWP: 

Access unutilised yield allocated to South Africa which is additional to the agreed Delivery Schedule 

(Scenario D). This yield would be available for a limited period, during the early years when the 

surplus yield that is not transferred to the Vaal River system, would supplement the yield available 

from the Caledon River with any surplus flowing into the Orange River system further downstream. 

Utilise any yield in excess of the proposed delivery schedule to South Africa (Scenario D) to supply 

Bloemfontein, specifically for the period from 2020 to about 2050, before the full yield of the LHWP is 

transferred to the Vaal River System from about 2053 onwards. This arrangement will require an 

amendment to the existing treaty. 

Water Requirements (million m 3 /a) 

700.0 

600.0 

500.0 

400.0 

300.0 

200.0 

100.0 

0.0 

2000 2010 2020 2030 2040 2050 2060 2070 

-100.0 

Water Requirements and Supply Scenarios 

For the purposes of this study and in order to determine a URV that can be compared to the URV’s 

determined for other surface water options, it has been assumed that a yield of 10 million m 3 /a would be 

made available from LHWP for Bloemfontein and surrounding towns and that this would be available up to 

the year 2050. 


Year 

Agreed Delivery Schedule per 

Treaty (Scenario D) 

Available supply from Phase II 

Polihali Katse to RSA 

Total Yield for Polihali Dam



The cost of water from the LHWP is uncertain at this stage, and is dependent on a number of factors such 

as: 

The Unit Reference Value (URV) of water from the scheme which was determined to be about 

R2.10/m 3 for a discount rate of 8%/a before taking hydropower benefits into account which would 

reduce the URV by about R0.20/m 3 i.e. a combined URV of about R1.90/m 3 . 

Losses down the Caledon River are likely to be relatively high (assumed to be equal to the 

requirements) because of potential abstractions (unauthorised) from the river upstream of the 

Tienfontein Pump Station. 

For purposes of this study, the unit cost of water has been assumed to be as indicated in the table below. 

URV costs proposed for this option are presented below: 


R 1.90 (Charge per m 3 for 

LHWP Water) 

Discount Rate 4% 6% 8% 

NPV of Water Costs (20 million m 3 p.a. for 10 million m 3 p.a. 

yield) (R million) 

746 529 397 

Unit Reference Value (R/m 3 ) 3.80 3.80 3.80 


o The base date for the above estimate is August 2009. 

o Costs associated with the upgrade of the Novo Transfer Scheme, or any other infrastructure at 

Tienfontein, Welbedacht or Knellpoort have been excluded. 


o The above cost further assumed that double the water will have to be purchased from LHWP, 

assuming that 50% of this water will be lost in the system as a result of river channel 

conveyance losses and unauthorised abstractions. 

o The above costing excludes the cost for transferring water from the LHWP scheme into the 

Caledon River. 

o NPV’s and URV’s are based on a 50 year life cycle cost. 



SECTION D 

Re-use of treated effluent 





D1. Planned Direct Re-use – New North Eastern 

1. OPTION LAYOUT 

See Figure common to all Re-use Interventions (before D1). 

2. BACKGROUND 

Approximately 75% of Bloemfontein drains naturally to three existing WWTW’s in one large catchment. Two 

of these works (Bloemspruit and Sterkwater) are currently operated beyond their capacity, which 

necessitated the construction of a new WWTW. 

The MLM is in the design phase to construct the new WWTW further downstream in the same catchment 

as the existing WWTWs, to allow further development in the northern, eastern, and western parts of the 

city, which is in agreement with the strategic N8 Corridor Development Plan between Botshabelo and 

Bloemfontein. 

Treated wastewater from the new North Eastern WWTW will be discharged into the Modder River system 

and may be available for agricultural use, if it is not re-used by the city of Bloemfontein. Therefore, the main 

focus of this intervention is to rather abstract the water for re-use at the planned new North Eastern 

WWTW. 


This option will require the construction of a new WTW, which would have an abstraction point at the new 

North Eastern WWTW. The WTW will have the necessary infrastructure, including Ultra Filtration, followed 

by a Reverse Osmosis, and Ultra-Violet radiation for disinfection, to purify water to potable standards. In 

addition, a booster pump station and rising main will also be required. 

The treated water can be pumped from the new WTW over an escarpment to the existing distribution 

reservoir at Maselspoort (which is approximately 6.5 km away) or pumped to a planned new distribution 

reservoir on Naval Hill in Bloemfontein for blending. 


Glen Agricultural College and private farmers are currently using most of the treated wastewater discharged 

into the Renoster and Modder River systems. 

The water to be re-used would only be from that associated with growth after 2009, within the new 

WWTW’s catchment area. 

The existing 68Ml/day discharge will bypass the new WWTW towards Bishops Glen Dam for agricultural 

use. 

Estimated yield is 11 million m 3 /a (30 Ml/d) 




The URVs for this option are based on preliminary costing. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 

Total capital cost (R million) 212 212 212 

Annual operating cost (R mill /annum) 13.9 13.9 13.9 

NPV Cost (R million) 472 387 334 


Note that the URV excludes escalation, but includes infrastructure and operating costs. 

5. POTENTIAL ECOLOGICAL IMPACTS 

New servitudes for pipeline routes over private farmland and/or urban areas. 

Waste product from the water treatment process including sludge and brine. 

6. POTENTIAL SOCIO-ECONOMICS IMPACTS 

No negative impacts envisaged. 

Public resistance to this intervention may be encountered, possibly stemming from concerns of poor design 

or control of processes which may allow sub-standard water to be introduced into the potable water supply 

system, or for religious reasons. 

7. POTENTIAL SURFACE WATER QUALITY IMPACTS 

The re-use of future effluent will have a positive impact on the system, as less treated effluent will be 

discharge into the natural stream. 

8. HEALTH RISKS 

There are unlikely to be any health risks associated with the direct re-use of the treated effluent, if all 

systems are functional (assuming RO was used). Failure of systems/processes could lead to poor quality 

water being supplied to end consumers. Stringent controls over the treatment process are required to 

ensure that sub-standard water cannot be introduced into the potable water supply system. 

9. OTHER ISSUES 

Any additional lighting in the vicinity of Maselspoort from new works could also interfere the operation of the 

Boyden Observatory, adjacent the Maselspoort Works. However, it is foreseen that this could be sufficiently 

mitigated in the design of the lighting for any new works. 




D2. Planned Indirect Re-use - Transfer to 

Upstream of Mockes Dam 

See Figure common to all Re-use Interventions (before D1) 


The works would include an abstraction point at the new North Eastern WWTW, plus a booster pump 

station, a possible stream crossing and 11 km of rising mains which will conduit the treated wastewater to 

the upper reached of a stream feeding Mockes Dam. The treatment facilities at the Maselspoort Weir (a few 

kilometres downstream of Mockes Dam) will be extended with new treatment technology and equipment. 

Required treatment process includes Reverse Osmosis in order to remove the build-up of dissolved salts in 

the river system. 



into the Renoster and Modder River systems. 

The water to be re-used would only be from that associated with growth after 2009, within the new North 

Eastern WWTW’s catchment area. 

The existing 68 Ml/day discharge will bypass the new WWTP towards Bishops Glen Dam for agricultural 

use. 




ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 










Disposal measures need to be developed for the waste products, which include sludge and brine. 

If the quality of the discharged effluent does not comply water the Water Use Licence conditions, 

there is the risk that sub-standard water could be discharged into the water resource. Stringent 

controls over the treatment process are required. 



Any additional lighting in the vicinity of Maselspoort from new works could also interfere the operation of the 

Boyden Observatory, adjacent the Maselspoort Works. However, it is foreseen that this could be sufficiently 

mitigated in the design of the lighting for any new works. 



D3. Planned Indirect Re-use – Krugersdrift Dam 


See Figure common to all Re-use Interventions (before D1) 

2. BACKGROUND 

All treatment works for Bloemfontein, Botshabelo, Mangaung, and Thaba Nchu (except Welvaart WWTW at 

5 Ml/day) discharge their treated wastewater into the Krugersdrift Dam catchment area. Although the dam is 

approximately 30 km from Bloemfontein, all future wastewater will end up in the dam if not intercepted 

upstream. 

Currently, no wastewater from Botshabelo or Thaba Nchu is reaching the dam, as it is intercepted at the 

Maselspoort Weir. The only water reaching the dam is excess surface run-off not intercepted by Mockes 

Dam and Rustfontein Dam, and the surplus wastewater from the Bloemfontein/Mangaung WWTW’s. 

Water can be abstracted at Krugersdrift Dam and pumped back to Bloemfontein. 

3. INTERVENTION DESCRIPTION 

The raw water at the Krugersdrift Dam, which will consist of excess surface runoff and treated wastewater 

from the city, will have to be purified using advanced technology. This treated water will then be pumped 

back to the main Bloem Water reservoir located at Brandkop approximately 35 km away. 

The works would include an abstraction point at the Krugersdrift Dam. Included will be Ultra Filtration, 

followed by a Reverse Osmosis and Ultra-Violet radiation for disinfection, to purify water to potable 

standards. Also included are a booster pump station and a 35 km rising main to Bloemfontein. 



into the Renoster and Modder River systems. The water to be re-used would only be from that associated 

with growth after 2009, from the WWTW’s in the catchment area. 

The flow of water from the various WWTW into the dam will have losses associated with it in the form of 

evaporation and groundwater infiltration. Furthermore, existing abstraction licences granted by the DWA will 

need to be managed appropriately to ensure they are not exceeded. 






ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 









Increased stream flows in the Modder River which may impact on natural flow patterns and may 

result in an increase of vegetation on riverbanks. 


there is the risk that sub-standard water could be discharged into the water resource. Stringent 

controls over the treatment process are required. 

No fatal flaws were identified. 




D4. Planned Direct Re-use – Bloemspruit 

See Figure common to all Re-use Interventions (after D1). 


The treated wastewater from the Bloemspruit WWTW would be purified to potable standards (this will 

typically include Ultra Filtration, followed by a Reverse Osmosis, and Ultra-Violet radiation for disinfection) 

and then pumped 3.8 km to a reservoir serving the Greater Bloemfontein area. At this reservoir it would be 

blended with the exiting supply fro Maselspoort WTW. 





ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 










there is the risk that sub-standard water could be discharged into the water resource. Stringent controls 

over the treatment process are required. 





There are no health risks associated with the direct re-use of the treated effluent, if all systems are 

functional. Failure of systems/processes could lead to poor quality water being supplied to end consumers. 

Stringent controls over the treatment process are required to ensure that sub-standard water cannot be 

introduced into the potable water supply system. 

Public resistance to this intervention may be encountered, possibly stemming from concerns of poor design 

or control of processes which may allow sub-standard water to be introduced into the potable water supply 

system. 



D5. Re-use of Treated Effluent – Direct use: Irrigation 

1. BACKGROUND 

Bloemfontein has currently a potable water distribution system. That means that all lawns, sports fields, 

parks etc. are irrigated with costly water “imported” from the Maselspoort or Welbedacht Dam WTW. 

A dual system could be investigated, where treated wastewater, treated to industrial standards, is returned 

to the city for the purpose of park and field irrigation. 

The two golf courses to the west of Bloemfontein as well as the botanical gardens (300 m 3 /day) currently 

use treated wastewater for irrigation purposes. 

The golf courses pay R 0.56/m 3 and the Botanical Gardens R 3 000/month. 

The potential exists for further re-use in Bloemfontein. 


This option entails the direct use of treated wastewater from any of the surrounding WWTW’s. Water could 

be distributed via an additional distribution system in the city for irrigation of public open spaces, school 

grounds, sport fields, and green street reserves (arterial roads with rose beddings etc). It could also be 

used for agricultural and industrial purposes where required. 

The scheme would include a new abstraction pump station at a WWTW, possibly the Bloemspruit WWTW 

due to its nearby proximity, a new distribution system, a possible elevated reservoir or in-line booster pump 

stations. 




A possible 100 hectares could be irrigated. The potential water re-use could be calculated as follows: 

Area: 100 ha 

Irrigation / day / area ± 5 mm 

Losses ± 30% 

Possible Re-use Volume / day 6.5 Ml/day 


No URVs have been determined for this option yet. 




Limited work opportunities could be created with the installation of the system. 

The use of treated wastewater on sports fields may have health implications. In 2004, the exemption 

for the use treated effluent by the University of the Free State was terminated due to health and 

environmental concerns (contact sport on the sports fields). 

7. POTENTIAL SURFACE WATER QUALITY IMPACTS 

No additional impact is foreseen, if treated effluent is used for irrigation purposes. 



SECTION E 

GROUNDWATER 



1. BACKGROUND 

E. Groundwater 

The primary study area is located within the Karoo Super Group geology. Dewetsdorp and Thaba Nchu 

sedimentary geology is characterised by purple and green shale and thick sandstone beds of the upper 

stage of the Beaufort Group. Reddersburg is also located in the Beaufort Group of the Karoo Super Group 

and the sedimentary geology is characterised by sandstone, shale, and mudstone beds of the middle stage 

of the Beaufort Group. 

Ikgomotseng and Edenburg are located in the Beaufort Group and more specifically in the Adelaide 

Formation of the Karoo Super Group. The sedimentary geology of Ikgomotseng is characterised by 

mudstone and sandstone beds. The geology of Edenburg is characterised by blue-grey and purple 

mudstones, which are interbedded with yellow sandstone and siltstone. The sedimentary geology of 

Wepener consists of feldspatic sandstone and grit as well as green shales of the Molteno stage of the 

Stormberg Group. The Bloemfontein geology consists of sandstone, shale, and mudstone of the lower 

stage of the Beaufort Group. The north-western side of Bloemfontein sedimentary geology has been 

intensively intruded by magmatic dolerite intrusives such as sills and dykes. 

The sedimentary geology of Ikgomotseng, Thaba Nchu, Reddersburg, Edenburg, Dewetsdorp and 

Wepener has also been intruded by magmatic dolerite intrusive structures, which includes sills and dykes. 

The baked contact zones between the dolerite intrusion and the sedimentary host rock has lead to the 

formation of fracture zones, which are the main source of groundwater. The contact between dolerite dykes 

and the host rock, within the weathered zone, remains therefore the most important target for groundwater 

exploration. 

Geological maps and aerial magnetic maps have revealed the presence of dolerite intrusives such as dykes 

and sill structures. Aerial photo interpretation has been utilised extensively for the preparation of the 

groundwater interventions due to limitation of the study to desktop and conceptual level for groundwater. 

No detailed geophysical maps exist regarding the spatial distribution of the dolerite dykes and sills of the 

study area and therefore aerial photo interpretation was employed to give an indication of the presence of 

lineaments in the target areas within the study area. The aerial photo interpretations revealed the presence 

on numerous lineaments in targets areas of the proposed groundwater interventions. Commercial irrigation 

from groundwater resources was also utilised as an indication of the groundwater abstraction potential. It 

must be noted that the aerial photo interpretation is based on visible lineaments on the surface and needs 

to be confirmed with proper field geophysical techniques and surveys. It is also important to note that aerial 

photo interpretations cannot detect deeper lying geological structures, which are not visible on the surface. 

Should any of the interventions be considered as a viable option for implementation in the near future it is 

recommended that a geophysical feasibility study be undertaken that includes field geophysical surveys to 

confirm the presence of dolerite dykes that were interpreted as lineaments as well as the identification of 

smaller dolerite intrusive structures not visible from aerial photo interpretations or aerial magnetics maps. 

The following potential groundwater interventions were identified and are located within the boundaries of 

the primary study area: 

Groundwater Intervention (1) - Ikgomotseng: This small community is located approximately 

45 km north west of Bloemfontein near the Krugersdrift Dam. Ikgomotseng derives its domestic 

water from the Krugersdrift Dam. In 2008 GHT Consulting performed groundwater exploration for the 



Ikgomotseng community to supplement the water resources (see Section E1 for the description of 

the proposed intervention). 

Groundwater Intervention (2) - Bloemfontein: The city of Bloemfontein currently utilised 

groundwater resources for their water requirements. The Bainsvlei irrigation area is situated to the 

northern and western side of Bloemfontein. The water used for irrigation in this area is 

predominantly provided by groundwater resources. The area is a known source of groundwater in 

relatively large volumes and was the subject of an earlier DWA study known as the Kalkveld 

Management Project. It is therefore proposed that the area as a whole or a section of the area be 

utilised for the groundwater needs of Bloemfontein should it be required in the future. See Section 

E2 for the proposed groundwater intervention. 

Groundwater Intervention (3) - Thaba Nchu: The Thaba Nchu area is situated approximately 58 

km east from Bloemfontein. The area is characterised by very small to medium sized communities 

that depend on surface water (Bloemwater) and groundwater for their domestic water needs. An 

unknown number of boreholes is utilised for water supply purposes. For the groundwater 

intervention it is proposed that a typical rural water supply approach be followed for the small 

communities of Thaba Nchu (see Section E3 for the description of the proposed intervention). 

Groundwater Intervention (4) - Reddersburg: The community of Reddersburg is located 60 km 

south-east of Bloemfontein. The current domestic water need for Reddersburg is supplied mainly 

from surface water resources (Bloemwater) and to a lesser extent from the groundwater resources of 

the commonage. The local municipality has an agreement with Bloemwater that a certain volume 

of water derived from surface water (pipeline) must be utilised on a monthly scale (see Section E4 

for the description of the proposed intervention). 

Groundwater Intervention (5) - Edenburg: The community of Edenburg is located 60 km south 

east of Bloemfontein. The current domestic water need for Edenburg is supplied mainly from surface 

water resources (Bloemwater) and to a lesser extent from the groundwater resources of the 

commonage. The local municipality has an agreement with Bloemwater that a certain volume of 

water derived from surface water (pipeline) must be utilised on a monthly scale (see Section E5 for 

the description of the proposed intervention). 

Groundwater Intervention (6) - Dewetsdorp: The community of Dewetsdorp is located 68 km 

south east of Bloemfontein. The current domestic water need for Dewetsdorp is supplied mainly 

from surface water resources (Bloemwater) and to a lesser extent from the groundwater resources 

of the commonage (see Section E6 for the description of the proposed intervention). 

Groundwater Intervention (7) – Wepener: The community of Wepener is located 104 km south 

east of Bloemfontein. The current domestic water need for Wepener is supplied mainly from surface 

water resources (Bloemwater) and to a lesser extent from the groundwater resources of the 

commonage (see Section E7 for the description of the proposed intervention). 

Groundwater Interventions (8 & 9) – Well field developments along the route of the existing 

pipelines: DWA suggested that the possibility of developing well fields along the route of existing 

pipelines such as the Botshabelo / Thaba Nchu pipeline, Dewetsdorp pipeline, Edenburg pipeline 

and the Caledon pipeline be investigated. The potential possibilities for this particular intervention 

can be studied in section 2 (see Section E8 for the description of the proposed intervention). 



Edenburg 

Ikgomotseng 

Bloemfontein 

Reddersburg 

Dewetsdorp 

Figure 2: A General Hydrolithology Map of the Study Area as Supplied by DWA 

Thaba Nchu 

Wepener 




E1. Ikgomotseng Aquifer 

Figure 3: The Ikgomotseng groundwater intervention area. The production boreholes are 

to be drilled on the southern side of the dolerite sill intrusion, which is also on 

the southern side of the storage reservoir for the Krugersdrift Dam water. 

Ikgomotseng is a small community located approximately 45 km north-west of Bloemfontein near the 

Krugersdrift Dam. Ikgomotseng derives its domestic water from the Krugersdrift Dam. 


Exploration Area to be targeted 

The small scale groundwater exploration programme conducted by GHT Consulting in 2008 confirmed 

the presence of a large dolerite sill structure on the community trust property of Ikgomotseng. Three 

boreholes were drilled. The average sustainable yield of the two successful boreholes derived from 

drilling was 31 536 m 3 /a. The groundwater quality was found to be of concern due to the presence of 

elevated fluoride concentrations. For this groundwater intervention it is proposed that at least 10 

boreholes be sited geophysically, percussion drilled and aquifer test pumped to determine the 

sustainable abstraction rates of the newly drilled boreholes. The boreholes are to be positioned on 

the commonage and trust property of Ikgomotseng. The boreholes are to be equipped according to 

the sustainable abstraction rate recommendations. The abstracted groundwater is to be pumped to 



the Ikgomotseng main reservoir for conjunctive use with the surface water (Krugersdrift Dam) as well 

as for dilution of the potential high fluoride concentrations or for treatment if necessary. 

3. Scheme Yield 

The Ikgomotseng scheme yield: 

Proposed 

Scheme 

Name 

Ikgomotseng 

Number 

of 

New 

Scheme 

Boreholes 

10 

production 

Number 

of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 10 

New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) (%) 

Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

2 177,390 31,536 208,926 482 4 231,200 

The estimated scheme yields were calculated by using the average sustainable yields estimated from 

data on the Karoo geology well fields of Petrusburg / Bolokanang, Edenville / Ngwathe, and 

Ikgomotseng for all the groundwater interventions except for the Bloemfontein / Bainsvlei intervention. 

The average sustainable yield estimated for a borehole was 48.6 m 3 /d over a 10-hour pump cycle per 

day. The recharge volumes to the local aquifers of the well fields were determined by using a 

recharge percentage of the Vegter recharge maps, the mean annual rainfall of the different localities, 

as well as the sizes of the commonages of the local municipalities. It must noted the capture zones of 

the conceptual well fields may differ from the assumed surface areas and are also influenced by the 

presence of preferential pathways resulting from dolerite intrusives as well as the topography of the 

selected localities of the well fields. A recharge surface of 3.4 km x 3.4 km was assumed for the 

Ikgomotseng scheme. 


The URVs for this option are based on an estimate costing performed and on assumed average yields 

per borehole. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 

Total capital cost (R million) 8.4 8.4 8.4 


NPV Cost (R million) 13.0 11.2 10.2 


Note that the URV excludes escalation and chemical treatment costs, but includes infrastructure and 

operating costs. 




Potential environmental impacts of utilising well fields include dewatering or lowering of 

sustainable yield of the local aquifer due to mismanagement or over utilisation. If the utilisation 

of well fields is not monitored and managed in a sustainable manner it may impact adjacent 

landowners, who may utilise groundwater for agricultural purposes and vice versa where the 

private landowner may have an impact on the groundwater resources of the well field. 

The groundwater quality was found to be of concern due to the presence of elevated fluoride 

concentrations. 

Contamination of the local aquifer by means of surface activities such as on-site sanitation, 

landfill sites, and leaking, unlined or over flowing sewage treatment works (oxidation dams) also 

poses a threat to the access to clean groundwater resources for communities. 




E2. Bloemfontein aquifer 

Figure 4: Locality map of the proposed Bainsvlei well field. The regions marked by the 

green polygons denote the areas where the well fields are proposed. These areas 

show the highest yield potential. This is based on the current density of 

established irrigation using groundwater. Also note the irrigation pivot circles on 

the aerial photo within the green polygons. 

The city of Bloemfontein currently does not utilise groundwater resources for its water requirements. 

The Bainsvlei irrigation area is situated to the northern and western side of Bloemfontein. The main 

source of water for irrigation in this area is provided by groundwater resources. This area is a known 

source of groundwater, which can supply relatively large volumes, and was the subject of an earlier 

DWA study known as the Kalkveld Management Project. It is therefore proposed that the area as a 

whole, or a section of the area, be utilised to meet the groundwater requirements of Bloemfontein 

should it be required in the future. 




The information presented below was adapted from a report titled: “Establishment of a Groundwater 

Management Plan for the Kalkveld Water User Association” (2004) as well as discussions regarding 

the proposed groundwater intervention with one of the main authors, Prof. G. van Tonder (The 

Institute for Groundwater Studies, UFS). 

In order to provide groundwater for Bloemfontein, it is proposed that the Bainsvlei area of the Kalkveld 

region be developed as a well field. In the terms of the scale of water consumption in Bloemfontein 

(approximately 60 - 80 Mm 3 /a), the Bainsvlei area (Zone 2) to the immediate north-western side of 

Bloemfontein should be developed as it can potentially provide 28 Mm 3 /a of water sustainably. 

Another area of interest, which can potentially provide groundwater for Bloemfontein, is the De Brug / 

Hagesdam aquifer. However, this area is deemed less attractive than the Bainsvlei area due to the 

fact that the current commercial abstraction (15.3 Mm 3 /a) is less than the estimated recharge volume 

of 33 Mm 3 /a. The reason for this is that only approximately 25 – 30% (western area) of the Zone 4 is 

utilised for commercial irrigation, which is possibly due to the absence or a less dense distribution of 

water bearing dolerite intrusive structures in Zone 4. The De Brug / Hagesdam area is therefore less 

attractive for well-field development, due to the lack of available groundwater that can be abstracted 

by means geological structures. De Brug / Hagesdam can also be considered a groundwater 

intervention for Bloemfontein but to a lesser extent. 

Bainsvlei and De Brug / Hagesdam can be combined as one intervention that can potentially yield 

43.3 Mm 3 /a but will mean the cessation of all commercial irrigation activities and appropriation of 

private landowner’s properties on a large scale making this groundwater intervention unfeasible due to 

the socio-economic impacts. The Petrusburg area was also taken into account, however the aquifer’s 

closest boundary is approximately 50 km from Bloemfontein and the furthest approximately 93 km. 

Therefore it is unlikely to be developed. The Petrusburg aquifer displays more potential in terms of 

sustainable utilisation of groundwater available (69 Mm 3 /a) but it is also utilised extensively for 

commercial irrigation. 

The groundwater intervention selected for this project is based on utilising the Bainsvlei aquifer and 

should be seen as an augmentation option for surface water resources, if future need should arise. 

The intensive commercial agricultural irrigation from groundwater resources in the Bainsvlei area 

indicate that the dolerite intrusive structures, which form the main target zones for groundwater 

exploration and abstraction, are present in sufficient spatial density for the development of well fields 

for production purposes. The surface area of the proposed Bainsvlei wellfield is 1 565 km 2 , the 

recharge percentage from mean annual rainfall is approximately 4%, which equates to 28 Mm 3 /a. The 

current abstraction from the proposed Bainsvlei wellfield area by predominantly commercial irrigators 

is 48.5 Mm 3 which is significantly more than the current annual recharge to the aquifer, indicating that 

the aquifer is currently being used in an unsustainable manner. The water bearing intrusive dolerites 

are usually identified by geophysical means such as the magnetic method or EM34. Currently no 

maps have been compiled to indicate the intrusive structures spatially on such scale and detail for the 

Kalkveld area. 

The groundwater intervention option for Bloemfontein proposes that Bainsvlei be developed as a 

conceptual intervention that can potentially yield 28 Mm 3 /a of water to Bloemfontein, which is equal to 

the average annual recharge available to the area and therefore can be sustainably abstracted. The 

average sustainable yield of a borehole is 43 362 m 3 /a if sited correctly on a dolerite dyke structure. 

The structures will have to be pinpointed by means of field geophysical surveys and spaced and 



aquifer tested for sustainability. Therefore approximately 645 boreholes are required to abstract 

28 Mm 3 /a of groundwater from the Bainsvlei area. The borehole field would be developed over a 

large surface area. Linked multiple storage facilities are envisaged that would eventually lead to a 

main storage facility at the well field site from where the water would be pumped 15 to 20 km to 

Bloemfontein. 


The Bloemfontein scheme yield: 

Proposed 

Scheme 

Name 

Bloemfontein 

Number of 

New Scheme 

Boreholes 

675 (645 

production and 

30 standby) 

Number of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 

645 New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) 

(%) 


Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

0 27,968,490 0 27,968,490 552 4 28,000,000 

The estimated scheme yields for other proposed intervations were calculated by assuming that the 

average sustainable yield for each borehole was 48.6 m 3 /d over a 10-hour pump cycle per day. For 

the Bloemfontein groundwater intervention, however, information from the Kalkveld Report was 

utilised to obtain an average yield of 118.8 m 3 /d over a 10-hour pump cycle per day per borehole. 

The recharge volumes to the local aquifers of the well field was determined by using a recharge 

percentage of the Vegter recharge maps as well as the mean annual rainfall of the area and a surface 

area of 1 565 km 2 . 


The URVs for this option are based on estimated costing and on assumed average yields per 

borehole. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 

Total capital cost (R million) 4 743 4 743 4 743 

Annual operating cost (R mill /annum) 39 39 39 

NPV Cost (R million) 4 388 4 753 4 465 



operating costs.



Potential environmental impacts of well fields include dewatering or lowering of sustainable yield of the 

local aquifer due to mismanagement or over utilisation. If the utilisation of well fields is not monitored 

and managed in a sustainable manner it may impact adjacent landowners, which may utilise 

groundwater for agricultural purposes and vice versa where the private landowners have an impact on 

the groundwater resources of the well field. 

Bainsvlei and De Brug / Hagesdam can be combined as one option that can potentially yield 43.3 

Mm 3 /a, but this will result in the cessation of all commercial irrigation activities and appropriation of 

private landowner’s properties on large scale making this groundwater intervention unfeasible due to 

the socio-economic impacts 




E3. Thaba Nchu Aquifer 

Figure 5: The locality map of Thaba Nchu. Lineaments (red polylines) were 

indentified, which indicate potential water bearing dykes to the north west 

and south west of Thaba Nchu. 

The Thaba Nchu area is situated approximately 58 km east from Bloemfontein. The area is 

characterised by groups of very small to medium sized communities that are depended on surface 

water (supplied by Bloemwater) and groundwater for their domestic water requirements. An unknown 

number of boreholes are utilised for water supply purposes. For this groundwater intervention, it is 

proposed that a typical rural water supply approach be followed for the small communities of Thaba 

Nchu. 


The proposed groundwater intervention for Thaba Nchu would use a rural water supply approach and 

it is assumed that the area will remain rural for the immediate future. Existing information regarding 

Thaba Nchu indicates that the some of the water needs of Thaba Nchu are derived from surface water 

sources (Bloemwater pipeline). A large number of boreholes are also utilised for the water 

requirements of the smaller Thaba Nchu communities. Existing information indicated that the 

groundwater qualities in these rural settlements are poor due to unlined or leaking on-site sanitation 

such as ventilated-in-pit latrines (VIPs). 



It is therefore proposed that only the smaller communities be equipped with boreholes and that these 

would be located far enough from the settlements to minimise potential contamination impacts by onsite 

sanitation. It is proposed that 50 boreholes be drilled not less than 300 m beyond the outskirts of 

the settlements and that these be equipped with motorised pumps connected to small reservoirs 

located within the rural settlements. 

It is estimated conceptually that, on the basis of a yield per borehole of 48.6 m 3 /d, the proposed rural 

wellfield can yield approximately 0.89 Mm 3 /a. The development of a dedicated well field in 

the vicinity of Thaba Nchu was ruled out due to the insufficient number of groundwater irrigation areas 

or lineaments displayed by the area on aerial photos and aerial magnetic data. The Thaba Nchu area 

is underlain by thick sandstone formations with a low spatial density of dolerite dyke intrusives and 

therefore not conducive to large scale groundwater abstraction in well field format. The observations 

regarding the presence of dolerite intrusives and groundwater potential were performed with aerial 

photo interpretation and aerial magnetic maps. Should the well field option be considered a necessity 

to meet the future water requirements of the Thaba Nchu / Botshabelo area a detailed geophysical / 

remote sensing study will have to be performed to determine the feasibility of large scale groundwater 

abstraction by means of wellfields. 


The Thaba Nchu rural water supply scheme yield: 

Proposed 

Scheme 

Name 

Thaba Nchu 

Number 

of 

New 

Scheme 

Boreholes 

50 

production 

Number 

of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 50 

New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) (%) 


Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

0 886,950 0 886,950 613 3 2,000,000 

The estimated scheme yields were calculated by using the average sustainable yields of the Karoo 

geology well fields of Petrusburg / Bolokanang, Edenville / Ngwathe, and Ikgomotseng for all the 

groundwater interventions except for the Bloemfontein / Bainsvlei intervention. The average 

sustainable yield derived for a borehole was 48.6 m 3 /d over a 10-hour pump cycle per day. The 

recharge volumes to the local aquifers of the boreholes were determined by using a recharge 

percentage from the Vegter recharge maps as well as the mean annual rainfall of the area and an 

estimated surface area of 10 km x 10 km. 


The URVs for this option are based on the estimated costing and on the assumed average yields per 

borehole.


ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 








Potential environmental impacts of well fields include dewatering or lowering of sustainable 

yield of the local aquifer due to mismanagement or over utilisation. If the utilisation of well fields 

is not monitored and managed in a sustainable manner it may impact adjacent landowners, 

which may utilise groundwater for agricultural purposes and vice versa where the private 

landowner have an impact on the groundwater resources of the well field. 


landfill sites, leaking, or unlined or over flowing sewage treatment works (oxidation dams) also 




E4, 5, 6, and 7. Town Groundwater Interventions 


The towns of Reddersburg (E4), Edenburg (E5), Dewetsdorp (E6), and Wepener (E7) receive surface 

water via a pipeline from Bloemwater. At least 70% of the water requirements of the towns must be 

derived from the pipeline and 30% from groundwater resources. Aerial photo interpretation revealed 

lineaments on the commonages, which may indicate potential dolerite dykes that may be targeted for 

groundwater abstraction purposes. Due to the existing boreholes on the commonages it is proposed 

that only five more production boreholes be developed for groundwater abstraction on each of the 

towns’ commonages. The estimated recharge volumes to the commonage indicted that if the 

additional proposed boreholes are drilled and utilised the commonages will reach their limit in terms 

of sustainable utilisation. 



E4. Reddersburg Town Groundwater Interventions 


Figure 6: The locality map of Reddersburg. Lineaments (red polylines) were indentified, 

which indicate potential water bearing dykes to the north and south west of the 

town on commonage. 

The community of Reddersburg is located 60 km south east of Bloemfontein. The current domestic 

water need for Reddersburg is derived from mainly surface water resources (Bloemwater) and to a 

lesser extent from groundwater resources. The local municipality has an agreement with Bloemwater 

that a certain volume of water derived from surface water (pipeline) must be utilised on a monthly 

scale. 


Aerial photo interpretations indicate the presence of lineaments and potential dolerite intrusives on 

and in the vicinity of the commonage of the town that can possibly be exploited for groundwater 

abstraction purposes. The groundwater intervention proposed for Reddersburg entails the drilling of 

eight new boreholes to be sited geophysically as well as the reconstruction or re-drilling of at least two 

existing boreholes in the eventuality of borehole collapse. Three of the eight boreholes will form part 

of the support production boreholes during well field maintenance and water emergencies. It appears 

from available records that the nine existing production boreholes were never aquifer test pumped to 

determine the sustainable abstraction rates. It is therefore proposed that the existing production 

boreholes be aquifer test pumped with the newly drilled boreholes to determine the sustainable yield 

of the commonage well field. Refurbishing of current production borehole equipment as well as the 

equipping of the newly drilled boreholes according to the sustainable rate recommendations is also 



proposed. It is estimated conceptually that the proposed well field can yield approximately 

0.24 Mm 3 /a. 


The Reddersburg scheme yield: 

Proposed 

Scheme Name 

Reddersburg 

Number 

of 

New 

Scheme 

Boreholes 

8 (5 

production 

and 3 

standby) 

Number 

of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 5 

New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) (%) 


Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

9 88,695 159,651 248,346 491 4 252,000 







assumed size of the commonage of the local municipality of 4.2 km x 3 km. 


The URVs for this option are based on the estimated costing and on the assumed average yield per 

borehole. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 








Potential environmental impacts of well fields include dewatering or lowering of sustainable yield 

of the local aquifer due to mismanagement or over utilisation. If the utilisation of well fields is 

not monitored and managed in a sustainable manner it may impact adjacent landowners, which 

may utilise groundwater for agricultural purposes and vice versa where the private landowner 

have an impact on the groundwater resources of the well field.





5. SOURCE OF DATA 

Refer to Appendix A for the report Groundwater Potential for Small Towns which was the source of 

the data used in deriving the proposed groundwater interventions. In that report upper and lower 

boundaries for the yields of the dolerite dyke structures in the vicinities of the towns are estimated. 

The upper boundaries were derived from the geometric mean of sustainable yield calculations using 

aquifer test data from a number of wellfields in the Karoo Super Group geology, including those of 

Petrusburg / Bolokanang, Edenville / Ngwathe, and Ikgomotseng. These calculations gave an average 

yield per borehole of 60.48 m 3 /d. The lower boundaries were derived from recharge water budget 

calculations which gave significantly lower yields. Consequently, a conservative value of 80% of the 

upper boundary of 60.48 m 3 /d per borehole was used for the groundwater intervention calculations. 

This value was 48.6 m 3 d per borehole. 



E5. Edenburg Town Groundwater Interventions 


Figure 7: The locality map of Edenburg. Lineaments (red polylines) were indentified, 

which indicate potential water bearing dykes to the north east of the town on 

commonage. 

The community of Edenburg is located 60 km south east of Bloemfontein. The current domestic water 

need for Edenburg is derived from mainly surface water resources (Bloemwater) and to a lesser 

extent from groundwater resources. The local municipality has an agreement with Bloemwater that a 

certain volume of water derived from surface water (pipeline) must be utilised on a monthly scale. 




abstraction purposes. The groundwater intervention proposed for Edenburg entails the drilling of eight 

new boreholes to be sited geophysically as well as the reconstruction or re-drilling of at least two 

existing boreholes in the eventually of borehole collapse. Three of the eight boreholes will form part of 

the support production boreholes during well field maintenance and water emergencies. Available 

information indicates that the 12 existing production boreholes were never aquifer test pumped to 

determine the sustainable abstraction rates. It is therefore proposed that the existing production 

boreholes be aquifer test pumped with the newly drilled boreholes to determine the sustainable yield 



of the commonage well field. Refurbishing of current production borehole equipment as well as the 



0.30 Mm 3 /a. 


The Edenburg scheme yield: 

Proposed 

Scheme Name 

Edenburg 

Number 

of 

New 

Scheme 

Boreholes 

8 (5 

production 

and 3 

standby) 

Number 

of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 5 

New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) (%) 


Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

12 88,695 212,868 301,563 441 5 400,000 

The estimated scheme yields were calculated by using the assumed average sustainable yields of the 

Karoo geology well fields of Petrusburg / Bolokanang, Edenville / Ngwathe, and Ikgomotseng for all 

the groundwater interventions except for the Bloemfontein / Bainsvlei intervention. The average 

sustainable yield derived for each borehole was 48.6 m 3 /d over a 10-hour pump cycle per day. The 



assumed area of commonage of 5 km x 4 km. 

. 



borehole. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 






operating costs.



Potential environmental impacts of well fields include dewatering or lowering of sustainable 

yield of the local aquifer due to mismanagement or over utilisation. If the utilisation of well fields 

is not monitored and managed in a sustainable manner it may impact adjacent landowners, 

which may utilise groundwater for agricultural purposes and vice versa where the private 

landowner have an impact on the groundwater resources of the well field. 






E6. Dewetsdorp Town Groundwater Interventions 


Figure 8: The locality map of Dewetsdorp. Lineaments (red polylines) were indentified, which 

indicate potential water bearing dykes to the east as well as the south-west of the 

town on commonage. 

The community of Dewetsdorp is located 68 km south east of Bloemfontein. The current domestic 

water need for Dewetsdorp is derived from mainly surface water resources (Bloemwater) and to a 

lesser extent from groundwater resources. 




abstraction purposes. The groundwater intervention proposed for Dewetsdorp entails the drilling of 

seven new boreholes to be sited geophysically. Two of the seven boreholes will form part of the 

support production boreholes during well field maintenance and water emergencies. Existing 

information indicates that the four production boreholes were re-constructed and aquifer test pumped 

in December 2007 to determined their sustainable abstraction rates. The combined sustainable rate 

of the four production boreholes is 80 154 m 3 /a. The newly drilled boreholes will be aquifer test 

pumped to determine their sustainable yields. Refurbishing of current production borehole equipment 

as well as the equipping of the newly drilled boreholes according to the sustainable rate 



recommendations is also proposed. It is estimated conceptually that the proposed well field can yield 

approximately 0.17 Mm 3 /a. 


The Dewetsdorp scheme yield: 

Proposed 

Scheme 

Name 

Dewetsdorp 

Number 

of 

New 

Scheme 

Boreholes 

7 (5 

production 

and 2 

standby) 

Number 

of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 5 

New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) (%) 

Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

4 88,695 80,154 168,849 593 3 320,000 


geology well fields of Petrusburg / Bolokanang, Edenville / Ngwathe and Ikgomotseng for all the 



recharge volumes to the local aquifers of the well fields were determined by using a recharge 


assumed size of the commonage of 3.9 km x 3.6 km. 


The URVs for this option are based on estimated costing and on the assumed average yield per 

borehole. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 













landowners, which may utilise groundwater for agricultural purposes and vice versa where the 

private landowner have an impact on the groundwater resources of the well field. 


landfill sites, leaking or unlined or over flowing sewage treatment works (oxidation dams) also 




E7. Wepener Town Groundwater Interventions 


Figure 9: The locality map of Wepener. Lineaments (red polylines) were indentified, which 

indicate potential water bearing dykes to the north, north-east as well as the west 

of the town on commonage. 

The community of Wepener is located 104 km south east of Bloemfontein. The current domestic 

water need for Wepener is derived mainly from surface water resources (Bloemwater) and to a lesser 

extent from groundwater resources. 




abstraction purposes. The groundwater intervention proposed for Wepener entails the drilling of 

seven new boreholes to be sited geophysically. Two of the seven boreholes will form part of the 

support production boreholes during well field maintenance and water emergencies. Information 

indicates that the four existing production boreholes were never aquifer test pumped to determine the 

sustainable abstraction rates. It is therefore proposed that the existing production boreholes be 

aquifer test pumped with the newly drilled boreholes to determine the sustainable yield of the 

commonage well field. Refurbishing of current production borehole equipment as well as the 





0.16 Mm 3 /a. 


The Wepener scheme yield: 

Proposed 

Scheme 

Name 

Wepener 

Number 

of 

New 

Scheme 

Boreholes 

7 (5 

production 

and 2 

standby) 

Number 

of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 5 

New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) 

(%) 

Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

4 88,695 70,956 159,651 593 5 432,000 





recharge volume to the local aquifers of the boreholes was determined by using a recharge 


assumed size of the commonage of 4.5 km x 3 km. 


The URVs for this option are based on estimated costing and on assumed average yields per 

borehole. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 














private landowners have an impact on the groundwater resources of the well field. 


landfill sites, leaking or unlined or over flowing sewage treatment works (oxidation dams) also 




E8. Groundwater Interventions Based on Wellfields Next 

to / in the Vicinity of Pipeline – De Hoek Reservoir 


Figure 10: The locality map of the De Hoek reservoir intervention. Lineaments (red 

polylines) were indentified, which indicate potential water bearing dykes to the 

south of the reservoir. The purple polylines indicate the edges of potential 

dolerite sills, and the pink polylines indicates the Caledon pipeline. 



and in the vicinity of the De Hoek reservoir that can possibly be exploited for groundwater abstraction 

purposes. The groundwater intervention proposes the drilling of 28 new boreholes to be sited 

geophysically. Three of the 28 boreholes will form part of the support production boreholes during 

well field maintenance and water emergencies. The newly drilled boreholes will be aquifer test 

pumped to determine their sustainable yields. It is estimated conceptually that the proposed well field 

can yield approximately 0.44 Mm 3 /a. 




The De Hoek reservoir scheme yield: 

Proposed 

Scheme 

Name 

De Hoek 

Reservoir 

Number 

of 

New 

Scheme 

Boreholes 

28 (25 

production 

and 3 

standby) 

Number 

of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 25 

New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) (%) 

Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

0 443,475 0 443,475 552 6 476,000 





recharge volumes to the local aquifers of the well fields were determined by using a recharge 

percentage of the Vegter recharge maps as well as the mean annual rainfall of the area and a surface 

area of the proposed wellfield of 6.8 km x 3.5 km. 



borehole. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 








Potential environmental impacts of utilising the well fields include dewatering or lowering of 




private landowner have an impact on the groundwater resources of the well field. 






E9. Groundwater Interventions Based on Well Fields next to / 

in the Vicinity of Pipeline – Lieukop off-take chamber 


Figure 11: The locality map of the Lieukop Off-take chamber intervention. Lineaments (red 

polylines) were indentified, which indicate potential water bearing dykes to the south 

of the reservoir. The purple polylines indicate the edges of potential dolerite sills, and 

the pink polylines indicate the Caledon and Botshabelo pipelines. 


Aerial photo interpretations indicate the presence of lineaments and potential dolerite intrusives in the 

vicinity of the Lieukop off-take chamber that can possibly be exploited for groundwater abstraction 

purposes. The groundwater intervention proposes the drilling of 27 new boreholes to be sited 

geophysically. Three of the 27 boreholes will form part of the support production boreholes during well field 

maintenance and water emergencies. The newly drilled boreholes will be aquifer test pumped to determine 

their sustainable yields. It is estimated conceptually that the proposed well field can yield approximately 

0.43 Mm 3 /a. 




The Lieukop Off-take chamber scheme yield: 

Proposed 

Scheme Name 

Lieukop Off-take 

Chamber 

Number 

of 

New 

Scheme 

Boreholes 

27 (24 

production 

and 3 

standby) 

Number 

of 

Existing 

Scheme 

Boreholes 

Estimated 

Average 

Yield of 24 

New 

Boreholes 

(m 3 /a) 

Estimated 

Average 

Yield of 

Existing 

Boreholes 

(m 3 /a) 

Total 

Estimated 

Average 

Yield 

(m 3 /a) 

Average 

Rainfall 

(mm/a) 

Vegter 

Recharge 

Percentage 

(20 mm/a) (%) 

Vegter 

Recharge 

To Aquifer 

(m 3 /a) 

0 425,736 0 425,736 593 5 438,080 

The estimated scheme yields were calculated by using the average sustainable yields of the Karoo geology 

well fields of Petrusburg / Bolokanang, Edenville / Ngwathe, and Ikgomotseng for all the groundwater 

interventions except for the Bloemfontein / Bainsvlei intervention. The average sustainable yield derived for 

a borehole was 48.6 m 3 /d over a 10-hour pump cycle per day. The recharge volumes to the local aquifers 

of the well field were determined by using a recharge percentage from the Vegter recharge maps as well as 

the mean annual rainfall of the area the surface area of the proposed wellfield of 3.7 km x 3.7 km. 


The URVs for this option are based on estimated costing and on assumed average yields per borehole. 

ITEM 

Discount Rate 

6 % 

Discount Rate 

8 % 

Discount Rate 

10 % 








Potential environmental impacts of utilising well fields include dewatering or lowering of sustainable 

yield of the local aquifer due to mismanagement or over utilisation. If the utilisation of well fields is 

not monitored and managed in a sustainable manner it may impact adjacent landowners, which may 

utilise groundwater for agricultural purposes and vice versa where the private landowner have an 

impact on the groundwater resources of the well field. 

Contamination of the local aquifer by means of surface activities such as on-site sanitation, landfill 

sites, leaking, or unlined or over flowing sewage treatment works (oxidation dams) also poses a 

threat to the access to clean groundwater resources for communities. 



SECTION F 

WATER TRADING 




F1. Water Trading 

Not all water allocated to agricultural users is currently being utilised. Therefore, there is potential for 

purchasing water rights from those agricultural users who are not fully utilising their allocations. In the 

Upper Orange River Catchment Area the most of the unutilised water is earmarked for previous 

disadvantage individuals. 

It is however important to note that water trading requires authorisation from the DWA. With the 

moratorium on water trading between commercial farmers the real value of the water use allocation could 

not be determined. 

2. OPPORTUNITIES FOR WATER TRADING 

2.1 The Caledon River upstream of the Welbedacht Dam 

Upstream of the Welbedacht Dam, farmers make use of a General Authorisation (GAs) to use water in the 

catchment area. Some of the GAs have not yet been taken up and can therefore be utilized in water 

trading. The assurance of supply currently is only 80%. 

2.2 The Caledon River downstream of the Welbedacht Dam 

Downstream of the Welbedacht Dam, farmers only receive water if the river flows into the Welbedacht Dam. 

The assurance of supply is also estimated to be 80 %. 

2.3 Modderrivier and Kalkveld WUA 

The Kalkveld area is mostly dependent on the groundwater for irrigation. Currently groundwater abstraction 

(45 million m 3 ) is more than the annual recharge (28 million m 3 ) in the Bainsvlei area. A full verification and 

validation of water use needs to be undertaken in this area in order to determine lawful and/or unlawful 

water use. 

The Modder River area has both surface water users and water supplied from the Krugersdrift Dam. The 

inflow of the Krugersdrift Dam is mostly water from the Bloemfontein area. The irrigation allocation is fully 

used. The assurance of supply for the irrigation has been 87 % over the last 30 years and over the last 10 

years only 80 %. The unlawful use of water upstream of the Krugersdrift Dam reduces the inflow to the 

dam. 

2.4 Orange-Riet and Vanderkloof WUA’s 

Both these WUA’s utilise water from Vanderkloof Dam. Water is released down the river for irrigation 

downstream of the Vanderkloof Dam, where it is diverted to the Main canal to supply the Orange-Riet WUA 

and the Ramah canals. 

The assurance of supply is 98% for both WUA’s. Unlawful water use exists next to the Orange River and 

needs to be managed. 



3. FINANCIAL COSTS 

Acquiring water via trading would need to be assessed on an individual basis. The associated costs for 

acquiring water via trading will vary from one potential source to another. Factors influencing this include 

current irrigation development potential, crop types, and potential revenue. 

Table F.1: Estimated Cost of Water Trading 

DESCRIPTION 

ALLOCATION 


Water Use Allocation Price 

(R/ha) 

Kalkfontein WUA 11 000 R 18 000 

Orange-Riet WUA (FS and NC) 11 000 R 30 000 

Proposed Modderrivier and Kalkveld WUA 8 130/8 640 R 24 000 

Proposed Vanderkloof WUA (FS and NC) 11 000 R 38 400 

Tierpoort Irrigation Board 9 000 - 

Wittespruit (Egmont Dam) Irrigation Board 6 100 - 

Caledon River upstream Welbedacht Dam ± 4 200 R 24 000 

Caledon River downstream Welbedacht Dam 7 620 R 28 000 

Leeuwrivier/Armenia Irrigation Board 6 100 - 

5. SOCIO-ECONOMIC 

The transfer of water from one water use sector to another can have a socio-economic impact on the area, 

specific issues include changes in land-use, job losses, etc. However, where unused allocations are traded 

this risk is not applicable. In addition, the importance of food security also needs to be looked at. 

In terms of the authorisation administrative process, the seller is required to provide an indemnity that no 

land claim has been lodged against his property in terms of the Restitution of Land Rights Act. The 

purchaser is required to apply for a water use licence. 


Specific strengths and weaknesses include: 

Strengths: 

Unused allocations from the system are by default integrated into the system; 

Environmental and social impacts can be managed; and 

The selling price can be negotiated. 

Weaknesses: 

Relies on a voluntary offer to sell; 

Needs expensive infrastructure; and 

Cannot be forced without Compulsory Licensing. 



SECTION G 

OTHER OPTIONS 




G1. Tunnel from Caledon 

This scheme, which was first proposed in 1947, entails a flood diversion structure in the vicinity of 

Jammersdrift Weir and a tunnel approximately 42 km long diverting flood water into the Modder Catchment. 

A dam in the Modder River Catchment with a capacity of at least the MAR of the Caledon River was 

proposed. 

This scheme was not undertaken at the time due to the large diameter tunnel required (to divert flood flows) 

and anticipated problems arising from siltation. It also proposed that any ultimate development on the 

Caledon River should entail a dam in the Caledon River with the diversion of controlled flows into the 

Modder catchment, without the necessity of providing any additional storage in the Modder River 

Catchement beyond what was already in existence. 

As this scheme was not implemented, the Welbedacht Dam on the Caledon River, the off channel storage 

dam at Knellpoort, and the Novo Transfer Scheme, were established. 

It is unlikely that a scheme of this nature could be implemented now due to the existing infrastructure 

development downstream of Jammersdrift Weir, the environmental water requirements, potential upstream 

development, and international obligations with Lesotho. The development of this scheme would reduce the 

yield of existing schemes downstream of Jammersdrift Weir. 




G2. New Dam on the Caledon River 

An additional dam on the Caledon River could provide additional yield to the Greater Bloemfontein Area. 

This intervention has not been further investigated as part of this preliminary screening workshop for the 

following reasons: 

Given the sedimentation loadings in the Caledon River, it would not be advisable to construct a new 

dam in the Caledon River upstream of Welbedacht Dam. 

A new dam would fall on the border of South Africa and Lesotho. 




G3. Transfer of Mine Water 

This scheme entails abstracting water from closed gold mines, treating the water to an acceptable standard 

and then pumping the water to the Greater Bloemfontein Area. Potential abstraction areas in close 

proximity to the Greater Bloemfontein Area are the goldfields of Welkom and/or Virginia. 

The scheme would entail an abstraction pump station, delivery pump station and a water treatment plant to 

remove any potential heavy metals and impurities in the water. 


In order to obtain a first order estimate of the potential costs associated with this scheme, an estimated 

yield of 20 million m 3 /a was used for the calculations. 


The URVs for this option are based on estimate costing performed and on a flow of 55Ml/d. 

ITEM 

Discount Rate 

4 % 

Discount Rate 

6 % 

Discount Rate 

8 % 


Annual operating cost (R mill /annum) 59 59 59 

NPV Cost (R million) 1,596 1,222 992 






9. REFERENCES 

DWAF, 2004a. Internal Strategic Perspective: Orange River System Overarching. Prepared by PDNA, 

WRP Consulting Engineers (Pty) Ltd, WMB, and Kwezi-V3 on behalf of the Directorate: National Water 

Resource Planning. DWAF Report No.: P RSA D000/00/0104. 

DWAF, 2004b. Internal Strategic Perspective: Upper Orange Water Management Area. Prepared by PDNA, 

WRP Consulting Engineers (Pty) Ltd, WMB, and Kwezi-V3 on behalf of the Directorate: National Water 

Resource Planning. DWAF Report No.: P RSA D000/00/0104. 

DWAF, 2002. Upper Orange Water Management Area: Water Resource Situation Assessment – Main 

Report – Volume 1 of 3. Prepared by Stewart Scott on behalf of the Directorate: Water Resource Planning. 

DWAF Report No.: P13000/00/010. 

Slabbert, N. 2007. The Potential Impact of an Inter-basin Water Transfer on the Modder and Caledon River 

Systems. PhD Thesis. University of Free State, Bloemfontein. 

World Commission on Dams, 2000. Orange River Development Project, South Africa, Case Study prepared 

as an input to the World Commission on Dams, Cape Town. www.dams.org. 


Water Reconciliation Strategy Study for the Large Bulk Water Supply Systems: Greater Bloemfontein Area 

Water Reconciliation Strategy Study for the 

Large Bulk Water Supply Systems: 

Greater Bloemfontein Area 

APPENDIX 1 

Preliminary Screening Workshop 

Proceedings 29 October 2009 

Appendix 1 – Preliminary Screening Workshop Proceedings 29 October 2009 June 2012


OPTIONS WORKSHOP ATTENDEES 

Mr Seef Rademeyer (DWA: NWRP) (SR) 

Ms Dragana Ristic (DWA: NWRP) (DR) 

Mr Peter Pyke (DWA: Central) (PP) 

Ms Lerato Bapela (DWA) (LB) 

Mr Louis van Oudtshoorn (Bloem Water) (LvO) 

Mr Steve Naude (Mangaung Municipality) (SN) 

Mr Dries Visser (DWA: Free State) (DV) 

Mr Roelf Jacobs (Free State Agriculture) (RJ) 

Mr Nic Knoetze (Orange-Riet Water User Association) (NK) 

Mr John Kegakilwe (Motheo DM – Department of Agriculture) (JK) 

Ms Patience Hadebe (Motheo DM – Department of Agriculture) (PH) 

Ms Andrea van Gensen (Eskom Distribution) (AvG) 

Ms Puleng Mofokeng (Department of Agriculture, Forestry and Fishery) (PM) 

Mr Mxolisi Mabindisa (Eskom Distribution) (MM) 

Mr Charles Wessels (Kalkveld Water User Association) (CW) 

Mr Hennie Grobler (Free State Department of Agriculture) (HG) 

Mr Tendayi Makombe (DWA: NWRP) (TMak) 

Mr Jurgo van Wyk (DWA: Water Resources Planning System) (JvW) 

Mr Richard Tloubatla (DWA: Free State) (RT) 

Mr Thabo Masike (DWA: WUE) (TMas) 

Mr Mabuti Moloi (Motheo District Municipality) (MM) 

Mr Edwin Mofokeng (Naledi Municipality) (EM) 

Mr Thulo Mohapi (DWA: Free State) (TMoh) 

Mrs Molly Ntwaeaborwa (DWA: FS) (MN) 

Mr Tebogo Mothwa (Free State: Department of Agriculture) (TMot) 

Dr Johan van der Merwe (Bloem Water) (JvdM) 

Mr Mike Killick (Aurecon) (MK) 

Ms Karen Versfeld (Aurecon) (KV) 

Mr Graeme Evers (Aurecon) (GE) 

Ms Terry Baker (ILISO Consulting) (TB) 

Mr Jaco Hough (GHT Consulting Scientists) (JH) 

Mr Sarel de Wet (Sarel de Wet Consulting Services) (SdW) 

Ms Bhavani Daya (ILISO Consulting) (BD) 

WELCOME AND OPENING 

TB welcomed everyone to the workshop and allowed each attendee to introduce themselves. 

SR relayed Mr Johan van Rooyen’s apologies for not being able to attend the workshop. On behalf of Mr 

van Rooyen, SR provided a brief background to this study. 

SR explained that the National Water Act, which was promulgated in 1998; requires the establishment of a 

National Water Resource Strategy (NWRS). The purpose of the NWRS is to provide a framework within 

which the water resources of the country will be managed. South Africa is a water scarce country and 

water resources are under stress. In order to make provision for current and future water requirements, the 

Department of Water Affairs (DWA) are currently developing strategies, such as the Reconciliation Strategy 

Study, to enhance the water supply. 

PRESENTATIONS 

The Preliminary Screening Workshop Starter Document was sent to all attendees from the week of the 2 

October 2009. The purpose of the Preliminary Screening Workshop Starter Document was to provide 

attendees with an over-view of the study area, including bulk infrastructure, current and future water 

requirements, and a water balance. In addition, information on all interventions which have been identified 

was described in the Preliminary Screening Workshop Starter Document. 



The purpose of the Preliminary Screening Workshop was thus to provide attendees with the opportunity to 

discuss the interventions that have been identified, screen out unfeasible interventions, and identify new 

interventions which were not included in the Preliminary Screening Workshop Starter Document. 

MK presented on the following topics discussed in more detail in the Preliminary Screening Workshop 

Starter Document: 

Scope of the study; 

Description of the Current Infrastructure; 

Available Supply 

Water Requirements; 

Water Balance 

Reconciliation Interventions; 

Other issues which could have an impact on Reconciliation; and 

Issues impacting on Reconciliation Options. 

WATER REQUIREMENTS SCENARIOS 

In order to prevent the anticipated shortages in water supply to the Greater Bloemfontein Area, the DWA 

has initiated a Reconciliation Strategy Study to explore supply and demand side interventions that can be 

implemented to meet anticipated future water requirements. 

In terms of urban requirements, there is limited information currently available on the losses for bulk water 

transmission losses and water treatment losses. Agricultural water requirements for this study were 

considered in two areas, namely the Modder-Riet Catchment and along the Caledon River. 

Other important comments from delegates: 

The following comments refer to Table 4.1 of the Preliminary Screening Workshop Starter Document: 

GE: Not all the water provided to the towns listed in Table 4.1 is provided by Bloem Water (BW) 

and Mangaung Local Municipality (MLM). Some of the water provided to these towns is supplied 

from boreholes within the area. 

MK: Groundwater is used to augment supply to some towns within the study area, but that the 

yields from these are very small. 

PP: Utilising other water resources, such as groundwater, may be a cheaper source of water to 

some towns than obtaining water from Bloem Water. 

LvO: In 2009, the figures provided by BW and MLM may be skew, as ± 30% of the water was 

provided from alternative resources (such as boreholes) and the rest by BW. The figures in the 

table are not incorrect just that there was a mismanagement issue at that time in terms of recording 

water sources at the MLM. 

The following comment refers to Section 4.1.1 of the Preliminary Screening Workshop Starter Document: 

LvO: An allowance of 8.5% has been added to the historical bulk water requirements to calculate 

the bulk losses from the system. This should be increased to 12%. 

The following comment refers to Figure 4.1 of the Preliminary Screening Workshop Starter Document: 

In 2002 the water consumption drops and then increased in the following year. LvO explained that 

this was as a result of the high rainfall experienced during that year. As such, the historical data 

presented in Figure 4.1 is influenced by climate. 

The following comment refers to Figures 4.2 and 4.3: 

PP: Concerned about using the term ‘residential uncontrolled water use’, as it implies that it is 

unmetered or unregistered water. A definition of ‘residential uncontrolled water use’ will be provided 

in the document. 



General comments: 

LvO stated that the situation facing Mohale Dam is a reality, in terms of the surplus yield. 

JH: Has global warming been taken into account and its influence on rainfall? MK responded that 

climate change would be taken into account in the scenario planning. 

LB asked how the options are compared. MK explained that a Unit Reference Value (URV) per m 3 

of water that can be used to compare options is calculated. This value took the cost of developing 

the resource and providing the bulk water as well as the quantity of water that can be supplied and 

time-period over which it will be available into account. 

MM queried the use of scenario planning to predict the future water requirements, as the use of a 

trend-line based on historical data can provide an indication of future requirements. PP responded 

that historical trends provide information on only one possible future requirement. The benefit of 

using scenario planning is that it takes into account multiple factors which can influence the future 

water requirements. 

LB queried whether the various scenarios considered the recession as a factor in the scenario 

analysis in terms of a demand for water. MK responded that the impact of the recession will be 

factored into the scenario planning in terms of population growth. DR added that migration rates 

can also be used as an indicator of the recession. 

PRELIMINARY OPTIONS WORKSHOP RECOMMENDATIONS 

a. URBAN WATER CONSERVATION AND DEMAND MANAGEMENT 

I. EFFICIENT USE OF WATER AND LOSS MANAGEMENT 

Recommendation: 

The MLM has developed a Water Conservation and Water Demand Management (WC/WDM) Strategy 

which should be referred to in the Preliminary Screening Workshop Starter Document. Institutional 

arrangements, however, have not been defined in the WC/WDM Strategy. The implementation of WC/WDM 

must be the major “intervention” recommended by this Study. If the MLM cannot manage their current 

supply of water then future schemes will not be supported by the DWA. 


TMas: The MLM has essential information and that needs to be shared with Government Departments, 

such as DWA Regional Office, to ensure implementation of this intervention. 

TMas: Metered information needs to be included in this Study. The person responsible for MLM’s Water 

Conservation Management should be contacted and be involved in this process. 

LvO stated that if the Local Municipality is involved perhaps an extension of infrastructure may not be 

needed as investigated in this assessment; perhaps another form of using current infrastructure can be 

investigated. 

ACTION ITEM: SR suggested that TMas should assist the project team to ensure that these responsible 

persons are identified and included in the study. 

b. AGRICULTURAL WATER CONSERVATION AND DEMAND MANAGEMENT 


It is important to initiate metering (both surface and groundwater abstractions) in the study area to identify 

illegal water use. In addition, metering also provides essential information to understand the yield of the 

system. 


NK: The DWA needs to ensure that the NWA is implemented, in terms of controlling and monitoring 

abstractions within the catchment management areas. 



CW stated that it is sad that the Water User Associations are not being used more efficiently as the 

National Water Act states as they could assist in the controlling of water use in their catchment; the lack of 

service delivery from DWAF has led to the theft and abuse of water. The illegal use of water needs to be 

monitored and metered by Municipalities. 

LvO queried whether there will be a direct pipeline to Bloemfontein. 

MK re-iterated that the point of the workshop is to screen out the options which will not be feasible. 

RJ stated that he had worked at the Tienfontein pump station and had noted the impact of the high 

sediment load on the pump station resulting in increased wear-and-tear on the equipment and high 

maintenance costs. As a result of the high sediment load, the Knellpoort Dam channel from Welbedacht 

Dam to Bloemfontein is deteriorating, and it is essential that it is rebuilt. 

TB queried if the assumption has been made that there is no unlawful use. 

SR stated that in terms of addressing unlawful water use, if the information is available regarding it then 

measures will be undertaken to eradicate it. 

MK clarified that all requirement figures used in the study exclude all unlawful use. The assumption is that 

the unlawful use of water will be dealt with and no longer take place in future. 

c. SURFACE WATER INTERVENTIONS 

II. UTILISING SURPLUS CAPACITY IN THE ORANGE RIVER BY PUMPING TO 

KNELLPOORT DAM FROM GARIEP DAM 


This intervention must be further investigated and the description of this intervention must be amended to 

reflect the actual scheme proposed. 

III. UTILISING SURPLUS CAPACITY IN THE ORANGE RIVER BY PUMPING TO 

KNELLPOORT DAM FROM VANDERKLOOF DAM 


The URV for this intervention is based on a 200 km pump system, which includes a pump station and rising 

main, from Vanderkloof Dam to Knellpoort Dam. This intervention will be further investigated. However the 

high pumping costs will probably exclude this intervention. 

IV. UTILISING SURPLUS CAPACITY IN THE ORANGE RIVER BY PUMPING TO 

KNELLPOORT DAM FROM BOSBERG / BOSKRAAI 


The URV for this intervention is based on a 100 km pump system, which includes a pump station and rising 

main. The cost of land acquisition and construction of the dam have been excluded. This intervention will 

be further investigated. However the high pumping costs will probably exclude this intervention. 

V. MODIFICATIONS TO WELBEDACHT DAM: EXTEND SCOUR OPERATIONS 

AND LOWER OUTLETS 


Alternative 1: Extended scour operations 

This will be required to maintain the existing yield of Welbedacht Dam 



Alternative 2: Lower outlets 

This intervention is fatally flawed as it would require that the entire dam wall be rebuilt. 

VI. MODIFICATIONS TO THE CALEDON-MODDER SYSTEM 


Include an additional option, namely the construction of a canal to transfer water upstream of Tienfontein 

Pump Station (close to Jammersdrift Weir) to Knellpoort Dam. 

VII. POLIHALI DAM – LESOTHO HIGHLANDS PHASE 2 


The URV is based on the incorrect tariff. The URV should be based on the Vaal prices for water. 

d. RE-USE OF TREATED EFFLUENT 

VIII. PLANNED INDIRECT RE-USE – NEW NORTH EASTERN WWTW 


The URV includes treatment and operating costs, as such the URVs cannot be compared with our surface 

water interventions. 

This option needs to be further investigated. 

IX. PLANNED INDIRECT RE-USE – TRANSFER TO UPSTREAM OF MOCKES 

DAM 



X. PLANNED INDIRECT RE-USE – KRUGERSDRIFT DAM 



XI. PLANNED INDIRECT RE-USE – BLOEMSPRUIT 



XII. RE-USE OF TREATED EFFLUENT – DIRECT USE: IRRIGATION 





e. GROUNDWATER 

XIII. IKGOMOTSENG AQUIFER 


These groundwater schemes provide local solutions, which may be more cost effective for local use than 

bringing water from the BW supply scheme. 

XIV. BLOEMFONTEIN (BAINSVLEI AQUIFER) 


This option has been screened out due to the high socio-economic costs associated with land 

expropriation, the cessation of farming activities in this area, and loss of jobs. 

XV. THABA NCHU AQUIFER 


This option has been screened out as a result of poor groundwater quality. 

XVI. TOWN GROUNDWATER INTERVENTIONS (REDDERSBURG, EDENBURG, 

DEWETSDORP, AND WEPPENER) 



XVII. GROUNDWATER INTERVENTIONS BASED ON WELL FIELDS NEXT TO / IN 

THE VICINITY OF PIPELINES – DE HOEK RESERVOIR 


This option has been screened out. 

XVIII. GROUNDWATER INTERVENTIONS BASED ON WELL FIELDS NEXT TO / IN 

THE VICINITY OF PIPELINES – LIEUKOP OFF-TAKE CHAMBER 


This option has been screened out. 

f. WATER TRADING 


There is potential for this option to be developed in future, however there are a number of socio-economic 

issues that need to be taken into consideration, namely loss of jobs and food security. 



g. OTHER OPTIONS 

XIX. TUNNEL FROM CALEDON 


This option has been screened out due to the impact that this option will have on the yield of existing 

infrastructure. 

XX. NEW DAM ON THE CALEDON RIVER 


This option has been screened out due to the high sediment loads of the Caledon River. 

XXI. TRANSFER OF MINE WATER 


This option should be further investigated. However, there is currently a demand for the mine water in the 

Welkom area and the water quality is a concern. 

NOTE: A summary of all the interventions and URVs is included in the following section. 

GENERAL DISCUSSION 

In order to determine the impact of the increasing electricity costs on the proposed interventions, a 

sensitivity analysis will be conducted. 

ACTION ITEM: MK to conduct a sensitivity analysis to determine the impact of electricity costs on the 

URVs. 

WAY FORWARD 

TB stated that the proceedings from this meeting would be sent to all present at the Workshop for 

comment, and that the comments raised from this Workshop would be used in the assessment of options. 

MK stated that a second Workshop would be held later in the project to present the findings of the detailed 

assessment of each Intervention. 

CLOSURE 

TB thanked everyone for attending the Workshop and for their contributions to the study. The meeting was 

closed at 14:00. 



Table 1: Summary of all interventions considered at the Preliminary Screening Workshop 

Option 

A - URBAN WATER CONSERVATION AND DEMAND MANAGEMENT 

A1 - Efficient use of water 

Yield URV Socio - 

Economic Ecological 

(Mm 3 /a) (R/m 3 ) 

0 0 1 1 

A2 - Loss management 

0 0 1 1 

B - AGRICULTURAL WATER CONSERVATION AND DEMAND MANAGEMENT 

Warrants further study? 

Yes / No / & Comment 

Yes. There will be no augmentation of bulk 

services without WC/WDM being addressed first 

Yes. There will be no augmentation of bulk 

services without WC/WDM being addressed first 

B1.1 - River release management 0 0 1 1 No 

B1.2 - Irrigation Practices 0 0 1 1 No 

B1.3 - Irrigation Canal Losses 0 0 1 1 No 

B1.4 - Farm Dam Losses 0 0 1 1 No 

B1.5 - Crop Selection 0 0 1 1 No 

B1.6 - Crop Deficit Irrigation 0 0 1 1 No 

B1.7 - Metering 0 0 1 1 No 

C - SURFACE WATER DEVELOPMENT OPTIONS 

C1 - Utilising surplus capacity in Orange River by 

pumping to Knellpoort Dam from Gariep Dam 10 5.3 2 2 Yes 

C2 - Utilise surplus capacity in Orange River 

system by pumping to Knellpoort Dam from 

Vanderkloof Dam 10 6.7 2 2 Yes 

C3 - Utilise surplus capacity in Orange River 

system by pumping to Knellpoort Dam from 

Bosberg/Boskraai Dam 10 4.2 2 2 Yes 

C4a - Modifications to Welbedacht Dam : Extend 

scour operations 0 0 1 1 Yes 

C4b - Modifications to Welbedacht Dam : Lower 

gates 0 0 1 1 No 

C5a - Modifications to Knellpoort System : 

Increased abstraction capacity of Novo 

Pumpstation 4.5 0 1 1 Yes 



Option 



(Mm 



3 /a) (R/m 3 C5b - Modifications to Knellpoort System : Raising 

) 

of Knellpoort Dam 

C5c - Modifications to Knellpoort System : Increase 

5.8 0 1 1 Yes 

capacity of Tienfontein pumpstation 

C5d - Modifications to Knellpoort System : New 

27 0 1 1 Yes 

pump station at Welbedacht Dam 

C5e - Modifications to Knellpoort System : 

39 0 1 1 Yes 

Combination of options 67 0 1 1 Yes 

C6 - Polihali Dam Lesotho Highlands Phase 2 

D - REUSE OF TREATED EFFLUENT 

D1 - Planned direct reuse - new North Eastern 

10 3.38 1 1 

Yes. The URVs are incorrect as they are based on 

the incorrect tariff structure 

WWTW 

D2 - Planned indirect reuse - Transfer to upstream 

10.8 4.1 2 2 

of Mockes Dam 10.8 4.8 1 2 Yes 

D3 - Treated indirect re-use - Krugersdrift Dam 10.8 5 1 2 Yes 

D4 - Planned direct re-use - Bloemspruit 

D5 - Re-use of treated effluent - Direct use: 

10.8 3.7 1 2 Yes 

Irrigation 

E - GROUNDWATER DEVELOPMENT OPTIONS 

0 0 1 1 Yes 

E1 - Ikgomotseng aquifer 0.21 5.08 2 2 Yes 

E2 - Bloemfontein aquifer (Bainsvlei aquifer) 28 15.58 3 2 No 

E3 - Thaba Nchu aquifer 0.89 5.35 1 2 Yes 

E4 - Reddersburg Aquifer 0.24 9.22 1 2 Yes 

E5 - Edenburg Aquifer 0.3 10.08 1 2 Yes 

E6 - Dewetsdorp Aquifer 0.17 7.35 1 2 Yes 

E7 - Weppener Aquifer 

E8 - Well-field developments along the route of the 

0.16 7.52 1 1 Yes 

existing pipelines : De Hoek Reservoir 

E9 - Well-field developments along the route of the 

0.43 9.42 1 1 No 

existing pipelines : Lieukop Off-take Chamber 0.43 10.3 1 1 No 

F - WATER TRADING 

B1 - Water Trading 3 0 No 



G - OTHER OPTIONS 

Option 



(Mm 3 /a) (R/m 3 ) 



G1 - Tunnel from Caledon to the Modder 0 0 0 0 No 

G2 - New dam on the Caledon River 0 0 0 0 No 

G3 - Transfer of mine water 4.6 4.6 1 1 Yes 

G4 - Canal option (to be developed still) 






APPENDIX 2 

Cost Estimates for Potential Interventions 

Appendix 2 – Cost Estimates for Potential Interventions June 2012


NOTE: 

No cost estimates were made for the following interventions: 

A1 

A2 

B1 

C4 

C6 

D5 

F1 



C1. Utilising surplus capacity in the Orange River by pumping to Knellpoort Dam from Gariep Dam 

Summary of 

costs 

Pumpstation R88,215,780 

Pipeline R503,266,750 

Subtotal R591,482,530 

Preliminary and 

General 

20% R118,296,506 


Contingencies 10% R70,977,904 


Professional 

Fees 

10% R78,075,694 

Total R858,832,634 

Pipeline 

Length 120 km 

Design velocity 1.5 m/s 

D 0.900 m 

A 0.636 m 2 

v 1.196 m/s 

Base 

Year 

SV (km) H Hf HGL P t Pipe Rate Cost 

km m m m m mm DN/t R/m R 

0 1259 10.671 1705 446 13 900/13 6407.24 R48,054,274 

7.5 1356 10.671 1695 339 10 900/10 5066.56 R37,999,194 

15 1269 10.671 1684 415 12 900/12 5961.36 R44,710,224 

22.5 1321 10.671 1673 352 10 900/10 5066.56 R37,999,194 

30 1418 10.671 1663 245 7 900/7 3716.71 R27,875,322 

37.5 1534 10.671 1652 118 7 900/7 3716.71 R27,875,322 

45 1538 10.671 1641 103 7 900/7 3716.71 R27,875,322 

52.5 1521 10.671 1631 110 7 900/7 3716.71 R27,875,322 

60 1581 10.671 1620 39 7 900/7 3716.71 R27,875,322 

67.5 1525 10.671 1609 84 7 900/7 3716.71 R27,875,322 

75 1528 10.671 1599 71 7 900/7 3716.71 R27,875,322 

82.5 1588 10.671 1588 0 7 900/7 3716.71 R27,875,322 

90 1525 10.671 1557 32 7 900/7 3716.71 R27,875,322 

97.5 1524 10.671 1546 22 7 900/7 3716.71 R27,875,322 

105 1518 10.671 1536 18 7 900/7 3716.71 R27,875,322 

112.5 1525 10.671 1525 0 7 900/7 3716.71 R27,875,322 

120 1449 1449 0 7 900/7 3716.71 

Pipeline Cost R503,266,750 

Pumpstation 

Flow to deliver 20 Mm 3 /a 

Pumping hours 

per day 

20 

Flow 0.761 m 3 /s 

H1 1259 m 

H2 1588 m 

Appendix 2 – Cost Estimates for Potential Interventions June 2012 

2012


HS 329 m 

C 125 

L 82.5 km 

Hf CW 117 m 

Kinematic 

viscosity (nu) 

1.13E-06 m²/s 

k 0.0005 m 

Re 952,783 

λ 0.0159 

0.949 

Hf CW/DW 106 m 

Hf 117 m 

HTOTAL 446 m 

Pump efficiency 85% 

Power 3921 kW 

Installed Power 5881 kW 

Rate 15,000 R/kW 

Pumpstation 

Cost 

Operation and 

Maintenance Costs 

Pumpstation Cost Split Annual O&M as % of CRC 

Mechanical Cost 50% Pipes 0.50% 

Electrical Cost 20% E&M 4.00% 

Civil Cost 30% Civil 0.25% 

Item Capital Cost 

Estimate 

A B C D E 

Preliminary 

and General 

(% of A) 

Contingencies 

(% of A+B) 

Total Capital 

Replace- 

ment Cost 

R88,215,780 

Annual O&M 

Cost 

20% 10% 

Pumpstation 88,215,780 17,643,156 10,585,894 116,444,830 3,347,789 

Pipeline 503,266,750 100,653,350 60,392,010 664,312,110 3,321,561 

Total 6,669,349 

Electricity Costs 

Megaflex (300 to 600 km Transmission Zone) 

Rate: c/kWh Rate: c/kWh (incl. rural 

subsidy and environmental 

levy charge) 

Rate Jun-Aug Sep-May Jun-Aug Sep-May 

3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 

Rural subsidy (c/kWh) 4.1 4.1 

Environmental levy charge 

(c/kWh) 

2.0 2.0 

Energy charge daily rate allocation - Megaflex 20 

Weekdays Saturday Sunday Total per 

week 



Peak 5 0 0 20.83333333 

Standard 11 7 0 51.66666667 

Off peak 8 17 24 67.5 

Hourly 

Charge 

Daily charge Monthly cost 

Service & Admin charge 

per account 

R161.25 

Network Access Charge 

(R/kVA/month) 

R9.73 

Network Demand Charge 

(R/kVA/month) 

R18.46 

Reactive Energy Charge 

(R/kVaRh) 

R0.08 

Transmission Network 

Charge (R/kVA/month) 

R4.92 

Pumpstation capacity 3,921 kW 

4,084 kVA 

Pumping hours per day 20 h 

Daily power usage 78,414 kWh/day 

Weighted average tariff 41 c/kWh 

Active Energy Cost R11,659,708 per annum 

Service & Admin Charge R58,856 per annum 

Network Access Charge R476,855 per annum 

Network Demand Charge R468,506 per annum 

Reactive Energy Charge R303,381 per annum 

Transmission network 

charge 

R241,123 per annum 

Total annual cost R13,208,429 

Orange River Costs 

Orange River Tariff 2.00 R/kl 

Flow 20000000 kl/annum 

Annual Orange River Cost R40,000,000 R59,877,779 



C2. Utilising surplus capacity in the Orange River by pumping to Knellpoort Dam from Vanderkloof Dam 

Summary of 

costs 





General 

20% R138,709,487 




Professional 

Fees 

10% R91,548,262 

Total R1,007,030,879 

Pipeline 

Length 200 km 


D 0.600 m 

A 0.283 m 2 

v 1.346 m/s 

Base 

Year 



0 1191 70.995 2127 936 17 600/17 5422.12 R135,552,921 

25 1460 62.476 2056 596 11 600/11 3673.27 R80,812,036 

47 1627 12.211 1993 366 7 600/7 2487.00 R10,694,085 

51.3 1454 67.303 1981 527 10 600/10 3378.23 R80,064,137 

75 1399 33.794 1914 515 10 600/10 3378.23 R40,200,980 

86.9 1359 37.201 1880 521 10 600/10 3378.23 R44,254,861 

100 1444 34.078 1843 399 8 600/8 2785.09 R33,421,137 

112 1566 36.917 1808 242 5 600/5 1887.74 R24,540,658 

125 1438 19.879 1772 334 7 600/7 2487.00 R17,408,976 

132 1408 17.039 1752 344 7 600/7 2487.00 R14,921,980 

138 1550 25.558 1735 185 5 600/5 1887.74 R16,989,686 

147 1474 8.519 1709 235 5 600/5 1887.74 R5,663,229 

150 1524 25.558 1701 177 5 600/5 1887.74 R16,989,686 

159 1675 45.437 1675 0 5 600/5 1887.74 R30,203,886 

175 1604 70.995 1604 0 5 600/5 1887.74 R47,193,572 

200 1445 1445 

Pumpstation 


Pumping hours 

per day 

20 

Flow 0.381 m 3 /s 

H1 1191 m 

H2 1675 m 

HS 484 m 


2012 

R598,911,829


C 125 

L 159 km 

Hf CW 452 m 

Kinematic 

viscosity (nu) 

1.13E-06 m²/s 

k 0.0005 m 

Re 714,587 

λ 0.0194 

1.002 


Hf 474 m 

HTOTAL 958 m 


Power 4206 kW 



Pumpstation 

Cost 

Operation and Maintenance 

Costs 






Estimate 

A B C D E 

Preliminary 

and General 

(% f A) 

Contingencies 

(% of A+B) 

Total Capital 

Replacement 

Cost 

R94,635,608.41 

Annual 

O&M 

Cost 

20% 10% 

Pumpstation 94,635,608 18,927,122 11,356,273 124,919,003 3,591,421 

Pipeline 598,911,829 119,782,366 71,869,419 790,563,614 3,952,818 

Total 7,544,239 





levy charge) 


3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 



(c/kWh) 

2.0 2.0 

Energy charge daily rate allocation - 

Megaflex 

20 


week 



Peak 5 0 0 20.83333333 

Standard 11 7 0 51.66666667 

Off peak 8 17 24 67.5 

Hourly Daily Monthly cost 

Charge charge 

Service & Admin charge per 

account 

R61.25 


(R/kVA/month) 

R9.73 


(R/kVA/month) 

R18.46 


(R/kVaRh) 

R0.08 

Transmission Network Charge 

(R/kVA/month) 

R4.92 

Pumpstation capacity 4,206 kW Annual 

Increase 

4,381 kVA 2012 15% 

Pumping hours per day 20 h 2013 15% 

Daily power usage 84,121 kWh/day 2014 15% 







Transimission network charge R258,671 per annum 





Annual Orange River Cost R20,000,000 



C3. Utilising surplus capacity in the Orange River by pumping to Knellpoort Dam from Bosberg/Boskraai 

Dam 

Summary of costs Base 

Year 





General 

20% R51,599,192 




Professional Fees 10% R34,055,467 

Total R374,610,136 

Pipeline 

Length 100 km 


D 0.600 m 

A 0.283 m 2 

v 1.346 m/s 



0 1330 21.298 1819 489 9 600/9 3171.10 R23,783,240 

7.5 1373 19.027 1798 425 8 600/8 2785.09 R18,660,135 

14.2 1552 13.063 1779 227 5 600/5 1887.74 R8,683,617 

18.8 1456 17.323 1766 310 6 600/6 2187.88 R13,346,064 

24.9 1569 14.483 1749 180 5 600/5 1887.74 R9,627,489 

30 1477 18.459 1734 257 5 600/5 1887.74 R12,270,329 

36.5 1405 24.138 1716 311 6 600/6 2187.88 R18,596,974 

45 1660 21.298 1692 32 5 600/5 1887.74 R14,158,072 

52.5 1441 11.075 1670 229 5 600/5 1887.74 R7,362,197 

56.4 1391 14.199 1659 268 5 600/5 1887.74 R9,438,714 

61.4 1645 12.495 1645 0 5 600/5 1887.74 R8,306,069 

65.8 1408 6.816 1567 159 5 600/5 1887.74 R4,530,583 

68.2 1483 9.371 1560 77 5 600/5 1887.74 R6,229,552 

71.5 1373 12.779 1551 178 5 600/5 1887.74 R8,494,843 

76 1538 18.459 1538 0 5 600/5 1887.74 R12,270,329 

82.5 1391 21.298 1498 107 5 600/5 1887.74 R14,158,072 

90 1434 28.398 1476 42 5 600/5 1887.74 R18,877,429 

100 1448 1448 


Pumpstation 


Pumping hours per 

day 

20 

Flow 0.381 m 3 /s 

H1 1330 m 


2012


H2 1645 m 

HS 315 m 

C 125 

L 61.4 km 

Hf CW 174 m 

Kinematic viscosity 

(nu) 

1.13E-06 m²/s 

k 0.0005 m 

Re 714,587 

λ 0.0194 

1.002 


Hf 183 m 

HTOTAL 498 m 


Power 2187 kW 



Pumpstation Cost R49,202,254.89 


Costs 






Estimate 

A B C D E 

Preliminary 

and General 

(% of A) 

Contingencies 

(% of A+B) 

Total Capital 

Replacement 

Cost 


Annual 

O&M 

Cost 

20% 10% 

Pumpstation 49,202,255 9,840,451 5,904,271 64,946,976 1,867,226 

Pipeline 208,793,707 41,758,741 25,055,245 275,607,693 1,378,038 

Total 


3,245,264 




levy charge) 


3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 



(c/kWh) 

2.0 2.0 


Megaflex 

20



week 

Peak 5 0 0 20.83333333 

Standard 11 7 0 51.66666667 

Off peak 8 17 24 67.5 

Hourly Charge Daily 

charge 

Monthly cost 


account 

R161.25 


(R/kVA/month) 

R9.73 


(R/kVA/month) 

R18.46 


(R/kVaRh) 

R0.08 


R4.92 

(R/kVA/month) 


Increase 

2,278 kVA 2012 15% 














Annual Orange River Cost R20,000,000 



C5a. Pumping from Welbedacht Dam to Knellpoort Dam 


Year 





General 

20% R51,558,452 


Contigencies 10% R30,935,071 



Total R374,314,363 

Pipeline 

Length 25.9 km 


D 1.400 m 

A 1.539 m 2 

v 1.299 m/s 



0 1413 0.693 1479 66 11 1 400/11 8637.21 R6,046,049 

0.7 1395 1.980 1478 83 11 1 400/11 8637.21 R17,274,427 

2.7 1427 0.990 1476 49 11 1 400/11 8637.21 R8,637,213 

3.7 1406 5.345 1475 69 11 1 400/11 8637.21 R46,640,952 

9.1 1408 0.990 1470 62 11 1 400/11 8637.21 R8,637,213 

10.1 1426 0.792 1469 43 11 1 400/11 8637.21 R6,909,771 

10.9 1410 0.198 1468 58 11 1 400/11 8637.21 R1,727,443 

11.1 1431 0.594 1468 37 11 1 400/11 8637.21 R5,182,328 

11.7 1406 4.949 1467 61 11 1 400/11 8637.21 R43,186,066 

16.7 1438 0.297 1462 24 11 1 400/11 8637.21 R2,591,164 

17 1405 1.782 1462 57 11 1 400/11 8637.21 R15,546,984 

18.8 1440 1.049 1460 20 11 1 400/11 8637.21 R9,155,446 

19.86 1402 1.445 1459 57 11 1 400/11 8637.21 R12,610,331 

21.32 1435 1.762 1458 23 11 1 400/11 8637.21 R15,374,240 

23.1 1410 1.049 1456 46 11 1 400/11 8637.21 R9,155,446 

24.16 1442 0.485 1455 13 11 1 400/11 8637.21 R4,232,234 

24.65 1418 1.237 1454 36 11 1 400/11 8637.21 R10,796,517 

25.9 1453 1453 

Pumpstation 

Flow to deliver 52.56 Mm 3 /a 


day 

20 

Flow 2.000 m 3 /s 

H1 1413 m 

H2 1453 m 


2012 

R223,703,823


HS 40 m 

C 125 

L 25.9 km 

Hf CW 26 m 


(nu) 

1.13E-06 m²/s 

k 0.0005 m 

Re 1,609,658 

λ 0.0159 

1.000 

Hf CW/DW 25 m 

Hf 26 m 

HTOTAL 66 m 


Power 1515 kW 




Operation and Maintenance Costs 





A B C D E 

Item Capital Cost Preliminary Contingencies Total Capital Annual 

Estimate and General (% of A+B) Replacement O&M 

(% of A) 

Cost 

Cost 

20% 10% 

Pumpstation 34,088,438 6,817,688 4,090,613 44,996,738 1,293,656 

Pipeline 223,703,823 44,740,765 26,844,459 295,289,047 1,476,445 

Total 2,770,101 





levy charge) 


3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 


Environmental levy charge (c/kWh) 2.0 2.0 


Megaflex 

20 


week 

Peak 5 0 0 20.83333333 



Standard 11 7 0 51.66666667 

Off peak 8 17 24 67.5 

Hourly 

Charge 


account 


(R/kVA/month) 


(R/kVA/month) 

Reactive Energy Charge (R/kVaRh) R0.08 

Daily 

charge 

R161.25 

Monthly cost 

R9.73 

R18.46 


(R/kVA/month) 

R4.92 


Increase 

1,578 kVA 2012 15% 













Flow kl/annum 

Annual Orange River Cost R - 



C5b. Gravity Main from Knellpoort Dam to Webedacht WTW 


Year 

Pumpstation R - 




General 

20% R44,740,765 





Total R324,817,951 

Pipeline 

Length 26 km 


D 1.400 m 

A 1.539 m 2 

v 1.308 m/s 



0 1453 1.253 1453 0 11 1 400/11 8637.21 R10,796,517 

1.25 1418 0.491 1452 34 11 1 400/11 8637.21 R4,232,234 

1.74 1442 1.063 1451 9 11 1 400/11 8637.21 R9,155,446 

2.8 1410 1.785 1450 40 11 1 400/11 8637.21 R15,374,240 

4.58 1435 1.464 1448 13 11 1 400/11 8637.21 R12,610,331 

6.04 1402 1.063 1447 45 11 1 400/11 8637.21 R9,155,446 

7.1 1440 1.805 1446 6 11 1 400/11 8637.21 R15,546,984 

8.9 1405 0.301 1444 39 11 1 400/11 8637.21 R2,591,164 

9.2 1438 5.013 1444 6 11 1 400/11 8637.21 R43,186,066 

14.2 1406 0.602 1439 33 11 1 400/11 8637.21 R5,182,328 

14.8 1431 0.201 1438 7 11 1 400/11 8637.21 R1,727,443 

15 1410 0.802 1438 28 11 1 400/11 8637.21 R6,909,771 

15.8 1426 1.003 1437 11 11 1 400/11 8637.21 R8,637,213 

16.8 1408 5.414 1436 28 11 1 400/11 8637.21 R46,640,952 

22.2 1406 1.003 1431 25 11 1 400/11 8637.21 R8,637,213 

23.2 1427 2.005 1430 3 11 1 400/11 8637.21 R17,274,427 

25.2 1395 0.702 1428 33 11 1 400/11 8637.21 R6,046,049 

25.9 1413 1427 


2012 

R223,703,823



Costs 






Estimate 

A B C D E 

Preliminary 

and 

General 

(% of A) 

Contingencies 

(% of A+B) 

Total Capital 

Replacement 

Cost 

Annual 

O&M 

Cost 

20% 10% 

Pumpstation - - - - - 

Pipeline 223,703,823 44,740,765 26,844,459 295,289,047 1,476,445 

Total 


1,476,445 




levy charge) 


3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 



(c/kWh) 

2.0 2.0 


Megaflex 

20 


week 

Peak 5 0 0 20.83333333 

Standard 11 7 0 51.66666667 

Off peak 8 17 24 67.5 


Charge charge 


account 

R161.25 


(R/kVA/month) 

R9.73 


(R/kVA/month) 

R18.46 


(R/kVaRh) 

R0.08 


(R/kVA/month) 

R4.92 

Pumpstation capacity - kW Annual 

Increase 

- kVA 2012 15% 


Daily power usage - kWh/day 2014 15% 




Active Energy Cost R - per annum 

Service & Admin Charge per annum 

Network Access Charge R - per annum 

Network Demand Charge R - per annum 

Reactive Energy Charge R - per annum 

Transimission network charge R - per annum 

Total annual cost R - 



Flow kl/annum 

Annual Orange River Cost R - 



D1. Planned direct re-use - New North Eastern 


Year 



Reservoir R26,213,676 

WTW R82,991,478 



General 

20% R29,197,414 





Total R211,973,224 

Pipeline 



D 0.600 m 

A 0.283 m 2 

v 1.228 m/s 



0 1332 9.589 1471 139 5 600/5 1887.74 R7,550,972 

4 1357 9.589 1461 104 5 600/5 1887.74 R7,550,972 

8 1375 9.829 1452 77 5 600/5 1887.74 R7,739,746 

12.1 1442 1.678 1442 0 5 600/5 1887.74 R1,321,420 

12.8 1429 1429 0 5 600/5 1887.74 


Pumpstation 



day 

24 

Flow 0.347 m 3 /s 

H1 1332 m 

H2 1442 m 

HS 110 m 

C 125 

L 12.1 km 

Hf CW 29 m 


(nu) 

1.13E-06 m²/s 

k 0.0005 m 

Re 652,061 

λ 0.0193 

1.000 

Hf CW/DW 30 m 


2012


Hf 30 m 

HTOTAL 140 m 


Power 561 kW 




Reservoir 

Capacity 30 Ml 

Rate 880 R/m 3 

Reservoir Cost R26,213,676.19 

WTW 

Design Feed Flow 

Rate 

44 Ml/d 

Product Flow Rate 1,379 m 3 /h 

Recovery 80% 

Time operational 90% 

Capacity of WTP 30 Ml/d 

Capacity of WTP 1,241 m 3 /h 

Average Flux Pass 1 25 (litre/m 2 .hr) 

Average Flux Pass 2 (litre/m 2 .hr) 

No of Passes (1 or 2) 1 

Area (membrane) 55,176 

Factor Pre-treatment 1.5 

Cap Pre treat Cost 

(WRC GRAPH) 

Cap Desal Cost 

(WRC GRAPH) 

30,179,886 

52,811,592 


Costs 






Estimate 

A B C D E 

Preliminary 

and 

General (% 

of A) 

Contingencies 

(% of A+B) 

Total Capital 

Replacement 

Cost 

R82,991,477.69 

Annual O&M 

Cost 

20% 10% 

Pumpstation 12,618,806 2,523,761 1,514,257 16,656,824 478,884 

Pipeline 24,163,109 4,832,622 2,899,573 31,895,304 159,477 

Reservoir 26,213,676 5,242,735 3,145,641 34,602,053 86,505 

WTW 82,991,478 16,598,296 9,958,977 109,548,751 3,149,527 

Total 3,874,392 







levy charge) 


3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 



(c/kWh) 

2.0 2.0 


Megaflex 

24 


week 

Peak 5 0 0 25 

Standard 11 7 0 62 

Off peak 8 17 24 81 


Charge charge 


account 

R161.25 


(R/kVA/month) 

R 9.73 


(R/kVA/month) 

R 18.46 


(R/kVaRh) 

R 0.08 


(R/kVA/month) 

R 4.92 

Pumpstation WTW 

Capacity 561 kW 1,366 kW 

584 kVA 1,423 kVA 

Pumping hours per day 24 h 24 h 

Daily power usage 13,460 kWh/day 32,775 kWh/day 

Weighted average tariff 41 c/kWh 41 c/kWh 

Active Energy Cost R2,001,432 per annum R4,873,383 per annum 

Service & Admin Charge R58,856 per annum R58,856 per annum 

Network Access Charge R68,212 per annum R166,092 per annum 

Network Demand Charge R67,017 per annum R163,184 per annum 

Reactive Energy Charge R52,076 per annum R126,803 per annum 

Transimission network charge R34,491 per annum R 83,985 per annum 

Total annual cost R2,282,085 R5,472,303 R 7,754,388 



D2. Planned Indirect Re-use - Transfer to upstream of Mockes Dam 


Year 

Pumpstation 1 R5,846,545 

Pipeline 1 R29,260,015 

Pumpstation 2 R17,177,141 

Pipeline 2 R37,754,858 


WTW R82,991,478 



General 

20% R39,848,742 





Total R289,301,870 

Pipeline 



D 0.600 m 

A 0.283 m 2 

v 1.228 m/s 



0 1333 4.795 1397 64 5 600/5 1887.74 R3,775,486 

2 1336 4.795 1392 56 5 600/5 1887.74 R3,775,486 

4 1358 4.795 1388 30 5 600/5 1887.74 R3,775,486 

6 1369 2.829 1383 14 5 600/5 1887.74 R2,227,537 

7.18 1363 2.973 1380 17 5 600/5 1887.74 R2,340,801 

8.42 1377 3.788 1377 0 5 600/5 1887.74 R2,982,634 

10 1356 3.116 1359 3 5 600/5 1887.74 R2,454,066 

11.3 1332 4.075 1356 24 5 600/5 1887.74 R3,209,163 

13 1352 5.034 1352 0 5 600/5 1887.74 R3,964,260 

15.1 1317 0.959 1326 9 5 600/5 1887.74 R755,097 

15.5 1325 1325 5 600/5 1887.74 


Pumpstation 



day 

24 

Flow 0.347 m 3 /s 

H1 1333 m 

H2 1377 m 

HS 44 m 

C 125 


2012


L 8.42 km 

Hf CW 20 m 


(nu) 

1.13E-06 m²/s 

k 0.0005 m 

Re 652,061 

λ 0.0193 

1.000 

Hf CW/DW 21 m 

Hf 21 m 

HTOTAL 65 m 


Power 260 kW 




Pipeline 



D 0.600 m 

A 0.283 m 2 

v 1.228 m/s 



0 1304 1.918 1493 189 5 600/5 1887.74 R1,510,194 

0.8 1365 2.757 1491 126 5 600/5 1887.74 R2,170,904 

1.95 1328 4.171 1488 160 5 600/5 1887.74 R3,284,673 

3.69 1353 8.990 1484 131 5 600/5 1887.74 R7,079,036 

7.44 1319 12.130 1475 156 5 600/5 1887.74 R9,551,979 

12.5 1334 11.507 1463 129 5 600/5 1887.74 R9,061,166 

17.3 1386 6.473 1451 65 5 600/5 1887.74 R5,096,906 

20 1445 1445 0 5 600/5 1887.74 


Pumpstation 



day 

24 

Flow 0.347 m 3 /s 

H1 1304 m 

H2 1445 m 

HS 141 m 

C 125 

L 20 km 

Hf CW 48 m 


(nu) 

1.13E-06 m²/s 

k 0.0005 m 

Re 652,061 



λ 0.0193 

1.000 

Hf CW/DW 50 m 

Hf 50 m 

HTOTAL 191 m 


Power 763 kW 




Reservoir 




WTW 


Rate 

44 Ml/d 


Recovery 80% 










(WRC GRAPH) 


(WRC GRAPH) 

30,179,886 

52,811,592 

R82,991,477.69 






A B C D 

Item Capital Cost Preliminary Contingencies Total Capital 

Estimate and General (% of A+B) Replacement 

(% of A) 

Cost 

20% 10% 

Pumpstations 23,023,686 4,604,737 2,762,842 30,391,265 

Pipelines 67,014,873 13,402,975 8,041,785 88,459,632 

Reservoir 17,177,141 3,435,428 2,061,257 22,673,826 

WTW 37,754,858 7,550,972 4,530,583 49,836,412 



Total 





levy charge) 


3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 




Megaflex 

24 


week 

Peak 5 0 0 25 


Off peak 8 17 24 81 

Hourly 

Charge 


Service & Admin charge per account R161.25 

Network Access Charge (R/kVA/month) R9.73 

Network Demand Charge (R/kVA/month) R18.46 



(R/kVA/month) 

R4.92 



271 kVA 1,423 kVA 




Active Energy Cost R927,304 per annum R4,873,383 per annum 





Transmission network charge R15,981 per annum R83,985 per annum 




D3. Planned Indirect Re-use - Krugersdrift Dam 


Year 




WTW R86,697,389 



General 

20% R42,237,057 





Total R306,641,035 

Pipeline 

Length 200 km 


D 0.600 m 

A 0.283 m 2 

v 1.228 m/s 



0 1249 23.973 1536 287 6 600/6 2187.88 R21,878,793 

10 1279 23.973 1512 233 5 600/5 1887.74 R18,877,429 

20 1328 23.973 1488 160 5 600/5 1887.74 R18,877,429 

30 1404 3.596 1464 60 5 600/5 1887.74 R2,831,614 

31.5 1460 13.185 1460 0 5 600/5 1887.74 R10,382,586 

37 1432 1432 0 5 600/5 1887.74 

Pumpstation 



day 

24 

Flow 0.347 m 3 /s 

H1 1249 m 

H2 1460 m 

HS 211 m 

C 125 

L 31.5 km 

Hf CW 76 m 


(nu) 

1.13E-06 m²/s 

k 0.0005 m 

Re 652,061 

λ 0.0193 

Hf CW/DW 78 m 


2012 

R72,847,851


Hf 78 m 

HTOTAL 289 m 


Power 1158 kW 




Reservoir 




WTW 


Rate 

45 Ml/d 


Recovery 80% 










(WRC GRAPH) 


(WRC GRAPH) 

31,365,504 

55,331,885 

R86,697,389.07 






A B C D E 

Item Capital Cost Preliminary Contingencies Total Capital Annual 

Estimate and General (% of A+B) Replacement O&M 

(% of A) 

Cost 

Cost 

20% 10% 

Pumpstation 26,055,414 5,211,083 3,126,650 34,393,147 988,803 

Pipeline 72,847,851 14,569,570 8,741,742 96,159,163 480,796 

Reservoir 25,584,631 5,116,926 3,070,156 33,771,714 84,429 

WTW 86,697,389 17,339,478 10,403,687 

Total 


4,844,194 






levy charge) 


3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 




Megaflex 

24 


week 

Peak 5 0 0 25 


Off peak 8 17 24 81 


Charge charge 


account 

R161.25 


(R/kVA/month) 

R9.73 


(R/kVA/month) 

R18.46 

Reactive Energy Charge (R/kVaRh) R 0.08 


(R/kVA/month) 

R4.92 


Capacity 1,158 kW 1,418 kW 

1,206 kVA 1,477 kVA 













D4. Planned Direct Re-use - Bloemspruit 


Year 




WTW R82,991,478 



General 

20% R24,710,357 





Total R179,397,189 

Pipeline 



D 0.600 m 

A 0.283 m 2 

v 1.228 m/s 



0 1376 2.397 1457 81 5 600/5 1887.74 R1,887,743 

1 1376 2.397 1454 78 5 600/5 1887.74 R1,887,743 

2 1381 0.216 1452 71 5 600/5 1887.74 R169,897 

2.09 1371 0.216 1452 81 5 600/5 1887.74 R169,897 

2.18 1378 0.767 1451 73 5 600/5 1887.74 R604,078 

2.5 1383 1.798 1451 68 5 600/5 1887.74 R1,415,807 

3.25 1402 0.743 1449 47 5 600/5 1887.74 R585,200 

3.56 1448 0.432 1448 0 5 600/5 1887.74 R339,794 

3.74 1439 1439 0 5 600/5 1887.74 


Pumpstation 



day 

24 

Flow 0.347 m 3 /s 

H1 1376 m 

H2 1448 m 

HS 72 m 

C 125 

L 3.56 km 

Hf CW 9 m 


(nu) 

1.13E-06 m²/s 

k 0.0005 m 


2012


Re 652,061 

λ 0.0193 

1.000 

Hf CW/DW 9 m 

Hf 9 m 

HTOTAL 81 m 


Power 324 kW 




Reservoir 




WTW 


Rate 

44 Ml/d 


Recovery 80% 










(WRC GRAPH) 

Cap Desal Cost (WRC 

GRAPH) 

30,179,886 

52,811,592 

R82,991,477.69 






A B C D 

Item Capital Cost Preliminary Contingencies Total Capital 

Estimate and General (% of A+B) Replacement 

(% of A) 

Cost 

20% 10% 

Pumpstation 7,286,471 1,457,294 874,376 9,618,141 

Pipeline 7,060,158 1,412,032 847,219 9,319,409 

Reservoir 26,213,676 5,242,735 3,145,641 34,602,053 



WTW 82,991,478 16,598,296 9,958,977 109,548,751 

Total 





levy charge) 


3 9 3 9 

Peak 197.46 55.08 203.57 61.19 

Standard 51.27 33.69 57.38 39.80 

Off peak 27.37 23.56 33.48 29.67 




Megaflex 

24 


week 

Peak 5 0 0 25 


Off peak 8 17 24 81 

Hourly 

Charge 


Service & Admin charge per account R161.25 

Network Access Charge (R/kVA/month) R9.73 

Network Demand Charge (R/kVA/month) R18.46 



(R/kVA/month) 

R4.92 



337 kVA 1,423 kVA 













E. Groundwater 

Proposed Scheme Name E1. 

Ikgomotseng 

Number of Proposed 

Boreholes 

Refurbishment & Testing of 

Existing Boreholes 

Geophysical & 

Geohydrological Activities 

E2. 

Bloemfontein 

E3. 

Thaba Nchu 

E4. 

Reddersburg 

E5. 

Edenburg 

E6. 

Dewetsdorp 

E7. 

Wepener 

E8a. 

De Hoek 

Reservoir 

10 675 50 8 8 7 7 28 27 

2 0 0 9 12 4 4 0 0 

E8b. 

Lieukop 

Off-take 

Chamber 

R220,000 R10,125,000 R1,000,000 R256,000 R288,000 R224,000 R238,000 R560,000 R540,000 

Percussion Drilling R500,000 R33,750,000 R2,500,000 R500,000 R500,000 R450,000 R450,000 R1,400,000 R1,350,000 

Aquifer Test Pumping Cost R220,000 R16,200,000 R1,100,000 R374,000 R440,000 R154,000 R242,000 R616,000 R594,000 

Pumping Equipment Cost R240,000 R16,875,000 R4,000,000 R340,000 R400,000 R140,000 R220,000 R560,000 R540,000 

DWAF Pump House Structure 

Cost 

R780,000 R43,875,000 R3,000,000 R1,105,000 R1,300,000 R715,000 R715,000 R1,820,000 R1,755,000 

Total (Well Field) R1,960,012 R120,825,675 R11,600,050 R2,575,017 R2,928,020 R1,683,011 R1,865,011 R4,956,028 R4,779,027 

Land Acquisition Costs (Very 

Rough Est from Sarel de Wet) 

R0 R881,134,250 R0 R0 R0 R0 R0 R107,100 R61,605 



Annual Opertional Cost (GW) R160,111 R13,745,502 R1,931,000 R243,656 R291,690 R157,100 R157,100 R419,779 R403,768 

Distance to Reservoir (km) 1km x 2 ~30km 

(centroid) 

Pipelines and Pump Stations 

Capital Cost 

Annual Operational & 

Maintenance Cost (Surface 

Infra) 

300m x 50 2km 2km 2km 2km 11km 9km 

R6,417,576 R3,741,787,598 R21,067,200 R4,125,528 R4,125,528 R4,652,366 R4,055,832 R37,913,141 R38,465,286 

R77,927 R25,493,459 R216,500 R39,656 R39,656 R41,319 R39,436 R370,787 R567,795 

Total Scheme Capital Cost R8,377,588 R4,743,747,523 R32,667,250 R6,700,545 R7,053,548 R6,335,377 R5,920,843 R42,976,269 R43,305,918 

Total Scheme Operational & 

Maintenance Cost 

R238,038 R39,238,962 R2,147,500 R283,312 R331,345 R198,419 R196,536 R790,566 R971,562 






APPENDIX 3 

Derivation of Unit Reference Values for Potential 

Interventions 

Appendix 3 – Derivation of Unit Reference Values for Potential Interventions June 2012


NOTE: 

No unit reference values were calculated for the following interventions: 

A1 

A2 

B1 

C4 

D5 

F1 



C1a. Utilising surplus capacity in the Orange River by pumping to Knellpoort Dam from Gariep Dam 

Year Capital O&M Electricty Orange 

River 

2012 

2013 

2014 

2015 

2016 

2017 

2018 

2019 

2020 

2021 

2022 

2023 

2024 

2025 

2026 

2027 

2028 

2029 

2030 

2031 

2032 

2033 

2034 

2035 

2036 

2037 

2038 

2039 

858,832,634 

429,416,317 

429,416,317 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

6,669,349 

- 

- 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

13,208,429 

- 

- 

15,692,935 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

40,000,000 

- 

- 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

Total Annual Yield URV 

429,416,317 

429,416,317 

62,362,284 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

20000000 

Appendix 3 – Derivation of Unit Reference Values for Potential Interventions June 2012 

- 

- 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000


2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

6,669,349 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

17,105,299 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

40,000,000 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

63,774,648 

2,058,397,987 

1,674,386,025 

1,431,100,899 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

391,921,799 

278,569,359 

209,004,398 


5.25 

6.01 

6.85


C2. Utilising surplus capacity in the Orange River by pumping to Knellpoort Dam from Vanderkloof 

Dam 


River 

Total Annual Yield 

10000000 

URV 

2012 

1,007,030,879 7,544,239 14,165,378 20,000,000 

2013 

503,515,440 - 

- 

- 

503,515,440 - 

2014 

503,515,440 - 

- 

- 

503,515,440 - 

2015 

- 

7,544,239 16,829,886 20,000,000 44,374,125 10,000,000 

2016 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2017 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2018 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2019 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2020 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2021 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2022 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2023 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2024 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2025 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2026 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2027 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2028 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2029 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2030 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2031 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2032 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2033 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2034 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2035 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2036 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2037 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

2038 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 

- 

7,544,239 18,344,576 20,000,000 45,888,815 10,000,000 



2039 

2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

7,544,239 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

18,344,576 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

45,888,815 

1,847,572,581 

1,561,030,641 

1,376,247,130 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

195,960,899 

139,284,680 

104,502,199 


9.43 

11.21 

13.17


C3. Utilising surplus capacity in the Orange River by pumping to Knellpoort Dam from 

Bosberg/Boskraai Dam 


River 

2012 

2013 

2014 

2015 

2016 

2017 

2018 

2019 

2020 

2021 

2022 

2023 

2024 

2025 

2026 

2027 

2028 

2029 

2030 

2031 

2032 

2033 

2034 

2035 

2036 

2037 

2038 

374,610,136 

187,305,068 

187,305,068 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

3,245,264 

- 

- 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

7,393,016 

- 

- 

8,783,643 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

20,000,000 

- 

- 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 


187,305,068 

187,305,068 

32,028,907 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

10000000 


- 

- 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000


2039 

2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

3,245,264 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

9,574,170 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

32,819,434 

995,704,904 

799,864,437 

676,357,285 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

10,000,000 

195,960,899 

139,284,680 

104,502,199 


5.08 

5.74 

6.47


C5a. Pumping from Welbedacht Dam to Knellpoort Dam 


River 

2012 

2013 

2014 

2015 

2016 

2017 

2018 

2019 

2020 

2021 

2022 

2023 

2024 

2025 

2026 

2027 

2028 

2029 

2030 

2031 

2032 

2033 

2034 

2035 

2036 

2037 

2038 

374,314,363 

187,157,182 

187,157,182 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

2,770,101 

- 

- 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

5,140,129 

- 

- 

6,106,987 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 



- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

187,157,182 

187,157,182 

8,877,088 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

20000000 

- 

- 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000


2039 

2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 

6,656,616 


- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

9,426,717 

537,234,340 

473,970,851 

431,825,757 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

20,000,000 

391,921,799 

278,569,359 

209,004,398 

1.37 

1.70 

2.07


C5b. Bi-direction pipeline between Knellpoort Dam and Webedacht WTW 


River 

2012 

2013 

2014 

2015 

2016 

2017 

2018 

2019 

2020 

2021 

2022 

2023 

2024 

2025 

2026 

2027 

2028 

2029 

2030 

2031 

2032 

2033 

2034 

2035 

2036 

2037 

2038 

374,314,363 

187,157,182 

187,157,182 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

2,770,101 

- 

- 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

3,337,906 

- 

- 

3,965,766 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 



- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

187,157,182 

187,157,182 

6,735,867 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

27000000 

- 

- 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000


2039 

2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

2,770,101 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 

4,322,685 


- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

7,092,786 

491,669,742 

441,624,575 

407,588,646 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

27,000,000 

529,094,428 

376,068,635 

282,155,937 

0.93 

1.17 

1.44


C6. Transfer of Water from Polihali Dam 

Year Yield (m 3 /a) Capital O&M 

10,000,000 R0 R38,000,000 

1 2010 0.00 R0 0 

2 2011 0.00 R0 0 

3 2012 10,000,000 R0 R38,000,000 

4 2013 10,000,000 R0 R38,000,000 

5 2014 10,000,000 R0 R38,000,000 

6 2015 10,000,000 R0 R38,000,000 

7 2016 10,000,000 R0 R38,000,000 

8 2017 10,000,000 R0 R38,000,000 

9 2018 10,000,000 R0 R38,000,000 

10 2019 10,000,000 R0 R38,000,000 

11 2020 10,000,000 R0 R38,000,000 

12 2021 10,000,000 R0 R38,000,000 

13 2022 10,000,000 R0 R38,000,000 

14 2023 10,000,000 R0 R38,000,000 

15 2024 10,000,000 R0 R38,000,000 

16 2025 10,000,000 R0 R38,000,000 

17 2026 10,000,000 R0 R38,000,000 

18 2027 10,000,000 R0 R38,000,000 

19 2028 10,000,000 R0 R38,000,000 

20 2029 10,000,000 R0 R38,000,000 

21 2030 10,000,000 R0 R38,000,000 

22 2031 10,000,000 R0 R38,000,000 

23 2032 10,000,000 R0 R38,000,000 

24 2033 10,000,000 R0 R38,000,000 

25 2034 10,000,000 R0 R38,000,000 

26 2035 10,000,000 R0 R38,000,000 

27 2036 10,000,000 R0 R38,000,000 

28 2037 10,000,000 R0 R38,000,000 

29 2038 10,000,000 R0 R38,000,000 

30 2039 10,000,000 R0 R38,000,000 

31 2040 10,000,000 R0 R38,000,000 

32 2041 10,000,000 R0 R38,000,000 

33 2042 10,000,000 R0 R38,000,000 

34 2043 10,000,000 R0 R38,000,000 

35 2044 10,000,000 R0 R38,000,000 



36 2045 10,000,000 R0 R38,000,000 

37 2046 10,000,000 R0 R38,000,000 

38 2047 10,000,000 R0 R38,000,000 

39 2048 10,000,000 R0 R38,000,000 

40 2049 10,000,000 R0 R38,000,000 

41 2050 10,000,000 R0 R38,000,000 

42 2051 10,000,000 R0 R38,000,000 

43 2052 10,000,000 R0 R38,000,000 

44 2053 10,000,000 R0 R38,000,000 

45 2054 10,000,000 R0 R38,000,000 

46 2055 10,000,000 R0 R38,000,000 

47 2056 10,000,000 R0 R38,000,000 

48 2057 10,000,000 R0 R38,000,000 

49 2058 10,000,000 R0 R38,000,000 

50 2059 10,000,000 R0 R38,000,000 

NPV NPV NPV URV 

4% 195,960,899 - 744,651,418 3.80 

6% 139,284,680 - 529,281,783 3.80 

8% 104,502,199 - 397,108,356 3.80 



D1. Planned direct re-use - New North Eastern 


River 

2012 

2013 

2014 

2015 

2016 

2017 

2018 

2019 

2020 

2021 

2022 

2023 

2024 

2025 

2026 

2027 

2028 

2029 

2030 

2031 

2032 

2033 

2034 

2035 

2036 

2037 

2038 

211,973,224 

105,986,612 

105,986,612 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

3,874,392 

- 

- 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

7,754,388 

- 

- 

9,212,989 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 



- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

105,986,612 

105,986,612 

13,087,381 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

10950000 

- 

- 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000


2039 

2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

3,874,392 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 

10,042,158 


- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

13,916,550 

471,873,619 

387,455,110 

333,774,974 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

214,577,185 

152,516,724 

114,429,908 

2.20 

2.54 

2.92


D2. Planned Indirect Re-use - Transfer to upstream of Mockes Dam 


River 

2012 

2013 

2014 

2015 

2016 

2017 

2018 

2019 

2020 

2021 

2022 

2023 

2024 

2025 

2026 

2027 

2028 

2029 

2030 

2031 

2032 

2033 

2034 

2035 

2036 

2037 

2038 

289,301,870 

144,650,935 

144,650,935 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

2,805,528 

- 

- 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

1,088,923 

- 

- 

1,293,749 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 


144,650,935 

144,650,935 

4,099,278 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

10950000 


- 

- 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000


2039 

2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

2,805,528 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

1,410,186 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

4,215,715 

355,333,374 

323,822,651 

301,913,629 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

214,577,185 

152,516,724 

114,429,908 


1.66 

2.12 

2.64


D3. Planned Indirect Re-use - Krugersdrift Dam 


River 

2012 

2013 

2014 

2015 

2016 

2017 

2018 

2019 

2020 

2021 

2022 

2023 

2024 

2025 

2026 

2027 

2028 

2029 

2030 

2031 

2032 

2033 

2034 

2035 

2036 

2037 

2038 

306,641,035 

153,320,518 

153,320,518 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

4,844,194 

- 

- 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,649,398 

- 

- 

5,523,950 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 


153,320,518 

153,320,518 

10,368,144 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10950000 


- 

- 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000


2039 

2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

4,844,194 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

6,021,105 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

10,865,299 

501,652,423 

432,016,263 

386,561,182 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

214,577,185 

152,516,724 

114,429,908 


2.34 

2.83 

3.38


D4. Planned Direct Re-use – Bloemspruit 

Year Capital O&M Electricity Orange 

River 

2012 

2013 

2014 

2015 

2016 

2017 

2018 

2019 

2020 

2021 

2022 

2023 

2024 

2025 

2026 

2027 

2028 

2029 

2030 

2031 

2032 

2033 

2034 

2035 

2036 

2037 

2038 

179,397,189 

89,698,594 

89,698,594 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

3,559,150 

- 

- 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

1,342,614 

- 

- 

1,595,160 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 



- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

89,698,594 

89,698,594 

5,154,310 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

10950000 

- 

- 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000


2039 

2040 

2041 

2042 

2043 

2044 

2045 

2046 

2047 

2048 

2049 

2050 

2051 

2052 

2053 

2054 

2055 

2056 

2057 

2058 

2059 

2060 

2061 

NPV 

(4%) 

NPV 

(6%) 

NPV 

(8%) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

3,559,150 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 

1,738,724 


- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

5,297,875 

272,870,042 

238,123,484 

215,206,331 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

10,950,000 

214,577,185 

152,516,724 

114,429,908 

1.27 

1.56 

1.88


E1. Ikgomotseng 

Year Estimated Average 

Yield of New 

Boreholes 

(m 3 /a) 

Capital O&M 

177,390 R8,377,588 R238,038 

1 2010 0.00 R8,377,588 R0.00 

2 2011 177,390 R0.00 R238,038 

3 2012 177,390 R0 R238,038 

4 2013 177,390 R0 R238,038 

5 2014 177,390 R0 R238,038 

6 2015 177,390 R0 R238,038 

7 2016 177,390 R0 R238,038 

8 2017 177,390 R0 R238,038 

9 2018 177,390 R0 R238,038 

10 2019 177,390 R0 R238,038 

11 2020 177,390 R0 R238,038 

12 2021 177,390 R0 R238,038 

13 2022 177,390 R0 R238,038 

14 2023 177,390 R0 R238,038 

15 2024 177,390 R0 R238,038 

16 2025 177,390 R0 R238,038 

17 2026 177,390 R0 R238,038 

18 2027 177,390 R0 R238,038 

19 2028 177,390 R0 R238,038 

20 2029 177,390 R0 R238,038 

21 2030 177,390 R0 R238,038 

22 2031 177,390 R0 R238,038 

23 2032 177,390 R0 R238,038 

24 2033 177,390 R0 R238,038 

25 2034 177,390 R0 R238,038 

26 2035 177,390 R0 R238,038 

27 2036 177,390 R0 R238,038 

28 2037 177,390 R0 R238,038 

29 2038 177,390 R0 R238,038 

30 2039 177,390 R0 R238,038 

31 2040 177,390 R0 R238,038 

32 2041 177,390 R0 R238,038 

33 2042 177,390 R0 R238,038 

34 2043 177,390 R0 R238,038 

35 2044 177,390 R0 R238,038 

36 2045 177,390 R0 R 238,038 

37 2046 177,390 R 0 R 238,038 



38 2047 177,390 R 0 R 238,038 

39 2048 177,390 R 0 R 238,038 

40 2049 177,390 R0 R238,038 

41 2050 177,390 R0 R238,038 

42 2051 177,390 R0 R238,038 

43 2052 177,390 R0 R238,038 

44 2053 177,390 R0 R238,038 

45 2054 177,390 R0 R238,038 

46 2055 177,390 R0 R238,038 

47 2056 177,390 R0 R238,038 

48 2057 177,390 R0 R238,038 

49 2058 177,390 R0 R238,038 

50 2059 177,390 R0 R238,038 

51 2060 177,390 R0 R238,038 

NPV NPV NPV 

4% 3,664,158 8,055,373 4,916,910 

6% 2,637,733 7,903,385 3,539,556 

8% 2,009,350 7,757,026 2,696,333 



E2. Bloemfontein 

Year Estimated 

Average Yield of 

New Boreholes 

(m 3 /a) 

Capital O&M 

27,968,490 R4,743,747,523 R39,238,962 

2010 0 R1,581,249,174 R0.00 

2011 0 R1,581,249,174 R0 

2012 9,322,830 R1,581,249,174 R13,079,654 

2013 27,968,490 R0 R39,238,962 

2014 27,968,490 R0 R39,238,962 

2015 27,968,490 R0 R39,238,962 

2016 27,968,490 R0 R39,238,962 

2017 27,968,490 R0 R39,238,962 

2018 27,968,490 R0 R39,238,962 

2019 27,968,490 R0 R39,238,962 

2020 27,968,490 R0 R39,238,962 

2021 27,968,490 R0 R39,238,962 

2022 27,968,490 R0 R39,238,962 

2023 27,968,490 R0 R39,238,962 

2024 27,968,490 R0 R39,238,962 

2025 27,968,490 R0 R39,238,962 

2026 27,968,490 R0 R39,238,962 

2027 27,968,490 R0 R39,238,962 

2028 27,968,490 R0 R39,238,962 

2029 27,968,490 R0 R39,238,962 

2030 27,968,490 R0 R39,238,962 

2031 27,968,490 R0 R39,238,962 

2032 27,968,490 R0 R39,238,962 

2033 27,968,490 R0 R39,238,962 

2034 27,968,490 R0 R39,238,962 

2035 27,968,490 R0 R39,238,962 

2036 27,968,490 R0 R39,238,962 

2037 27,968,490 R0 R39,238,962 

2038 27,968,490 R0 R39,238,962 

2039 27,968,490 R0 R39,238,962 

2040 27,968,490 R0 R39,238,962 

2041 27,968,490 R0 R39,238,962 

2042 27,968,490 R0 R39,238,962 

2043 27,968,490 R0 R39,238,962 

2044 27,968,490 R0 R39,238,962 

2045 27,968,490 R0 R39,238,962 

2046 27,968,490 R0 R39,238,962 



2047 27,968,490 R0 R39,238,962 

2048 27,968,490 R0 R39,238,962 

2049 27,968,490 R0 R39,238,962 

2050 27,968,490 R0 R39,238,962 

2051 27,968,490 R0 R39,238,962 

2052 27,968,490 R0 R39,238,962 

2053 27,968,490 R0 R39,238,962 

2054 27,968,490 R0 R39,238,962 

2055 27,968,490 R0 R39,238,962 

2056 27,968,490 R0 R39,238,962 

2057 27,968,490 R0 R39,238,962 

2058 27,968,490 R0 R39,238,962 

2059 27,968,490 R0 R39,238,962 

2060 27,968,490 R0 R39,238,962 


4% 535,281,275 4,388,110,405 750,983,748 9.60 

6% 375,335,380 4,226,697,938 526,584,403 12.66 

8% 278,027,495 4,075,032,483 390,064,327 16.06 



E3. Thaba Nchu 



New Boreholes 

(m 3 /a) 

Capital O&M 

886,950 R32,667,250 R2,147,500 

2010 0 R16,333,625 R0.00 

2011 443,475 R16,333,625 R1,073,750 

2012 886,950 R0 R2,147,500 

2013 886,950 R0 R2,147,500 

2014 886,950 R0 R2,147,500 

2015 886,950 R0 R2,147,500 

2016 886,950 R0 R2,147,500 

2017 886,950 R0 R2,147,500 

2018 886,950 R0 R2,147,500 

2019 886,950 R0 R2,147,500 

2020 886,950 R0 R2,147,500 

2021 886,950 R0 R2,147,500 

2022 886,950 R0 R2,147,500 

2023 886,950 R0 R2,147,500 

2024 886,950 R0 R2,147,500 

2025 886,950 R0 R2,147,500 

2026 886,950 R0 R2,147,500 

2027 886,950 R0 R2,147,500 

2028 886,950 R0 R2,147,500 

2029 886,950 R0 R2,147,500 

2030 886,950 R0 R2,147,500 

2031 886,950 R0 R2,147,500 

2032 886,950 R0 R2,147,500 

2033 886,950 R0 R2,147,500 

2034 886,950 R0 R2,147,500 

2035 886,950 R0 R2,147,500 

2036 886,950 R0 R2,147,500 

2037 886,950 R0 R2,147,500 

2038 886,950 R0 R2,147,500 

2039 886,950 R0 R2,147,500 

2040 886,950 R0 R2,147,500 

2041 886,950 R0 R2,147,500 

2042 886,950 R0 R2,147,500 

2043 886,950 R0 R2,147,500 

2044 886,950 R0 R2,147,500 

2045 886,950 R0 R2,147,500 

2046 886,950 R0 R2,147,500 



2047 886,950 R0 R2,147,500 

2048 886,950 R0 R2,147,500 

2049 886,950 R0 R2,147,500 

2050 886,950 R0 R2,147,500 

2051 886,950 R0 R2,147,500 

2052 886,950 R0 R2,147,500 

2053 886,950 R0 R2,147,500 

2054 886,950 R0 R2,147,500 

2055 886,950 R0 R2,147,500 

2056 886,950 R0 R2,147,500 

2057 886,950 R0 R2,147,500 

2058 886,950 R0 R2,147,500 

2059 886,950 R0 R2,147,500 

2060 886,950 R0 R2,147,500 


4% 17,910,774 30,806,763 43,365,903 4.14 

6% 12,793,971 29,945,948 30,977,004 4.76 

8% 9,666,541 29,127,178 23,404,810 5.43 



E4. Reddersburg 



New Boreholes 

(m 3 /a) 

Capital O&M 

88,695 R6,700,545 R283,312 

2010 0 R3,350,273 R0.00 

2011 44,348 R3,350,273 R141,656 

2012 88,695 R0 R283,312 

2013 88,695 R0 R283,312 

2014 88,695 R0 R283,312 

2015 88,695 R0 R283,312 

2016 88,695 R0 R283,312 

2017 88,695 R0 R283,312 

2018 88,695 R0 R283,312 

2019 88,695 R0 R283,312 

2020 88,695 R0 R283,312 

2021 88,695 R0 R283,312 

2022 88,695 R0 R283,312 

2023 88,695 R0 R283,312 

2024 88,695 R0 R283,312 

2025 88,695 R0 R283,312 

2026 88,695 R0 R283,312 

2027 88,695 R0 R283,312 

2028 88,695 R0 R283,312 

2029 88,695 R0 R283,312 

2030 88,695 R0 R283,312 

2031 88,695 R0 R283,312 

2032 88,695 R0 R283,312 

2033 88,695 R0 R283,312 

2034 88,695 R0 R283,312 

2035 88,695 R0 R283,312 

2036 88,695 R0 R283,312 

2037 88,695 R0 R283,312 

2038 88,695 R0 R283,312 

2039 88,695 R0 R283,312 

2040 88,695 R0 R283,312 

2041 88,695 R0 R283,312 

2042 88,695 R0 R283,312 

2043 88,695 R0 R283,312 

2044 88,695 R0 R283,312 

2045 88,695 R0 R283,312 

2046 88,695 R0 R283,312 



2047 88,695 R0 R283,312 

2048 88,695 R0 R283,312 

2049 88,695 R0 R283,312 

2050 88,695 R0 R283,312 

2051 88,695 R0 R283,312 

2052 88,695 R0 R283,312 

2053 88,695 R0 R283,312 

2054 88,695 R0 R283,312 

2055 88,695 R0 R283,312 

2056 88,695 R0 R283,312 

2057 88,695 R0 R283,312 

2058 88,695 R0 R283,312 

2059 88,695 R0 R283,312 

2060 88,695 R0 R283,312 


4% 1,791,077 6,318,931 5,721,100 6.72 

6% 1,279,397 6,142,365 4,086,679 8.00 

8% 966,654 5,974,423 3,087,708 9.37 



E5. Edenburg 



New Boreholes 

(m 3 /a) 

Capital O&M 

88,695 R7,053,548 R331,345 

2010 0 R3,526,774 R0.00 

2011 44,348 R3,526,774 R165,673 

2012 88,695 R0 R331,345 

2013 88,695 R0 R331,345 

2014 88,695 R0 R331,345 

2015 88,695 R0 R331,345 

2016 88,695 R0 R331,345 

2017 88,695 R0 R331,345 

2018 88,695 R0 R331,345 

2019 88,695 R0 R331,345 

2020 88,695 R0 R331,345 

2021 88,695 R0 R331,345 

2022 88,695 R0 R331,345 

2023 88,695 R0 R331,345 

2024 88,695 R0 R331,345 

2025 88,695 R0 R331,345 

2026 88,695 R0 R331,345 

2027 88,695 R0 R331,345 

2028 88,695 R0 R331,345 

2029 88,695 R0 R331,345 

2030 88,695 R0 R331,345 

2031 88,695 R0 R331,345 

2032 88,695 R0 R331,345 

2033 88,695 R0 R331,345 

2034 88,695 R0 R331,345 

2035 88,695 R0 R331,345 

2036 88,695 R0 R331,345 

2037 88,695 R0 R331,345 

2038 88,695 R0 R331,345 

2039 88,695 R0 R331,345 

2040 88,695 R0 R331,345 

2041 88,695 R0 R331,345 

2042 88,695 R0 R331,345 

2043 88,695 R0 R331,345 

2044 88,695 R0 R331,345 

2045 88,695 R0 R331,345 

2046 88,695 R0 R331,345 



2047 88,695 R0 R331,345 

2048 88,695 R0 R331,345 

2049 88,695 R0 R331,345 

2050 88,695 R0 R331,345 

2051 88,695 R0 R331,345 

2052 88,695 R0 R331,345 

2053 88,695 R0 R331,345 

2054 88,695 R0 R331,345 

2055 88,695 R0 R331,345 

2056 88,695 R0 R331,345 

2057 88,695 R0 R331,345 

2058 88,695 R0 R331,345 

2059 88,695 R0 R331,345 

2060 88,695 R0 R331,345 


4% 1,791,077 6,651,830 6,691,071 7.45 

6% 1,279,397 6,465,962 4,779,546 8.79 

8% 966,654 6,289,172 3,611,207 10.24 



E6. Dewetsdorp 



New Boreholes 

(m 3 /a) 

Capital O&M 

88,695 R6,335,377 R198,419 

2010 0 R3,167,689 R0.00 

2011 44,348 R3,167,689 R99,209 

2012 88,695 R0 R198,419 

2013 88,695 R0 R198,419 

2014 88,695 R0 R198,419 

2015 88,695 R0 R198,419 

2016 88,695 R0 R198,419 

2017 88,695 R0 R198,419 

2018 88,695 R0 R198,419 

2019 88,695 R0 R198,419 

2020 88,695 R0 R198,419 

2021 88,695 R0 R198,419 

2022 88,695 R0 R198,419 

2023 88,695 R0 R198,419 

2024 88,695 R0 R198,419 

2025 88,695 R0 R198,419 

2026 88,695 R0 R198,419 

2027 88,695 R0 R198,419 

2028 88,695 R0 R198,419 

2029 88,695 R0 R198,419 

2030 88,695 R0 R198,419 

2031 88,695 R0 R198,419 

2032 88,695 R0 R198,419 

2033 88,695 R0 R198,419 

2034 88,695 R0 R198,419 

2035 88,695 R0 R198,419 

2036 88,695 R0 R198,419 

2037 88,695 R0 R198,419 

2038 88,695 R0 R198,419 

2039 88,695 R0 R198,419 

2040 88,695 R0 R198,419 

2041 88,695 R0 R198,419 

2042 88,695 R0 R198,419 

2043 88,695 R0 R198,419 

2044 88,695 R0 R198,419 

2045 88,695 R0 R198,419 

2046 88,695 R0 R198,419 



2047 88,695 R0 R198,419 

2048 88,695 R0 R198,419 

2049 88,695 R0 R198,419 

2050 88,695 R0 R198,419 

2051 88,695 R0 R198,419 

2052 88,695 R0 R198,419 

2053 88,695 R0 R198,419 

2054 88,695 R0 R198,419 

2055 88,695 R0 R198,419 

2056 88,695 R0 R198,419 

2057 88,695 R0 R198,419 

2058 88,695 R0 R198,419 

2059 88,695 R0 R198,419 

2060 88,695 R0 R198,419 


4% 1,791,077 5,974,561 4,006,804 5.57 

6% 1,279,397 5,807,617 2,862,128 6.78 

8% 966,654 5,648,828 2,162,494 8.08 



E7. Wepener 



New Boreholes 

(m 3 /a) 

Capital O&M 

88,695 R5,920,843 R196,536 

2010 0 R2,960,422 R0.00 

2011 44,348 R2,960,422 R98,268 

2012 88,695 R0 R196,536 

2013 88,695 R0 R196,536 

2014 88,695 R0 R196,536 

2015 88,695 R0 R196,536 

2016 88,695 R0 R196,536 

2017 88,695 R0 R196,536 

2018 88,695 R0 R196,536 

2019 88,695 R0 R196,536 

2020 88,695 R0 R196,536 

2021 88,695 R0 R196,536 

2022 88,695 R0 R196,536 

2023 88,695 R0 R196,536 

2024 88,695 R0 R196,536 

2025 88,695 R0 R196,536 

2026 88,695 R0 R196,536 

2027 88,695 R0 R196,536 

2028 88,695 R0 R196,536 

2029 88,695 R0 R196,536 

2030 88,695 R0 R196,536 

2031 88,695 R0 R196,536 

2032 88,695 R0 R196,536 

2033 88,695 R0 R196,536 

2034 88,695 R0 R196,536 

2035 88,695 R0 R196,536 

2036 88,695 R0 R196,536 

2037 88,695 R0 R196,536 

2038 88,695 R0 R196,536 

2039 88,695 R0 R196,536 

2040 88,695 R0 R196,536 

2041 88,695 R0 R196,536 

2042 88,695 R0 R196,536 

2043 88,695 R0 R196,536 

2044 88,695 R0 R196,536 

2045 88,695 R0 R196,536 

2046 88,695 R0 R196,536 



2047 88,695 R0 R196,536 

2048 88,695 R0 R196,536 

2049 88,695 R0 R196,536 

2050 88,695 R0 R196,536 

2051 88,695 R0 R196,536 

2052 88,695 R0 R196,536 

2053 88,695 R0 R196,536 

2054 88,695 R0 R196,536 

2055 88,695 R0 R196,536 

2056 88,695 R0 R196,536 

2057 88,695 R0 R196,536 

2058 88,695 R0 R196,536 

2059 88,695 R0 R196,536 

2060 88,695 R0 R196,536 


4% 1,791,077 5,583,635 3,968,779 5.33 

6% 1,279,397 5,427,615 2,834,967 6.46 

8% 966,654 5,279,215 2,141,972 7.68 



E8a. De Hoek Reservoir 



New Boreholes 

(m 3 /a) 

Capital O&M 

443,475 R42,976,269 R790,566 

2010 0 R21,488,135 R0.00 

2011 221,738 R21,488,135 R395,283 

2012 443,475 R0 R790,566 

2013 443,475 R0 R790,566 

2014 443,475 R0 R790,566 

2015 443,475 R0 R790,566 

2016 443,475 R0 R790,566 

2017 443,475 R0 R790,566 

2018 443,475 R0 R790,566 

2019 443,475 R0 R790,566 

2020 443,475 R0 R790,566 

2021 443,475 R0 R790,566 

2022 443,475 R0 R790,566 

2023 443,475 R0 R790,566 

2024 443,475 R0 R790,566 

2025 443,475 R0 R790,566 

2026 443,475 R0 R790,566 

2027 443,475 R0 R790,566 

2028 443,475 R0 R790,566 

2029 443,475 R0 R790,566 

2030 443,475 R0 R790,566 

2031 443,475 R0 R790,566 

2032 443,475 R0 R790,566 

2033 443,475 R0 R790,566 

2034 443,475 R0 R790,566 

2035 443,475 R0 R790,566 

2036 443,475 R0 R790,566 

2037 443,475 R0 R790,566 

2038 443,475 R0 R790,566 

2039 443,475 R0 R790,566 

2040 443,475 R0 R790,566 

2041 443,475 R0 R790,566 

2042 443,475 R0 R790,566 

2043 443,475 R0 R790,566 

2044 443,475 R0 R790,566 

2045 443,475 R0 R790,566 

2046 443,475 R0 R790,566 



2047 443,475 R0 R790,566 

2048 443,475 R0 R790,566 

2049 443,475 R0 R790,566 

2050 443,475 R0 R790,566 

2051 443,475 R0 R790,566 

2052 443,475 R0 R790,566 

2053 443,475 R0 R790,566 

2054 443,475 R0 R790,566 

2055 443,475 R0 R790,566 

2056 443,475 R0 R790,566 

2057 443,475 R0 R790,566 

2058 443,475 R0 R790,566 

2059 443,475 R0 R790,566 

2060 443,475 R0 R790,566 


4% 8,955,387 40,528,656 15,964,418 6.31 

6% 6,396,986 39,396,189 11,403,656 7.94 

8% 4,833,270 38,319,033 8,616,082 9.71 



E8b. Lieukop Off-take Chamber 



New Boreholes 

(m 3 /a) 

Capital O&M 

425,736 R43,305,918 R971,562 

2010 0 R21,652,959 R0.00 

2011 212,868 R21,652,959 R485,781 

2012 425,736 R0 R971,562 

2013 425,736 R0 R971,562 

2014 425,736 R0 R971,562 

2015 425,736 R0 R971,562 

2016 425,736 R0 R971,562 

2017 425,736 R0 R971,562 

2018 425,736 R0 R971,562 

2019 425,736 R0 R971,562 

2020 425,736 R0 R971,562 

2021 425,736 R0 R971,562 

2022 425,736 R0 R971,562 

2023 425,736 R0 R971,562 

2024 425,736 R0 R971,562 

2025 425,736 R0 R971,562 

2026 425,736 R0 R971,562 

2027 425,736 R0 R971,562 

2028 425,736 R0 R971,562 

2029 425,736 R0 R971,562 

2030 425,736 R0 R971,562 

2031 425,736 R0 R971,562 

2032 425,736 R0 R971,562 

2033 425,736 R0 R971,562 

2034 425,736 R0 R971,562 

2035 425,736 R0 R971,562 

2036 425,736 R0 R971,562 

2037 425,736 R0 R971,562 

2038 425,736 R0 R971,562 

2039 425,736 R0 R971,562 

2040 425,736 R0 R971,562 

2041 425,736 R0 R971,562 

2042 425,736 R0 R971,562 

2043 425,736 R0 R971,562 

2044 425,736 R0 R971,562 

2045 425,736 R0 R971,562 

2046 425,736 R0 R971,562 



2047 425,736 R0 R971,562 

2048 425,736 R0 R971,562 

2049 425,736 R0 R971,562 

2050 425,736 R0 R971,562 

2051 425,736 R0 R971,562 

2052 425,736 R0 R971,562 

2053 425,736 R0 R971,562 

2054 425,736 R0 R971,562 

2055 425,736 R0 R971,562 

2056 425,736 R0 R971,562 

2057 425,736 R0 R971,562 

2058 425,736 R0 R971,562 

2059 425,736 R0 R971,562 

2060 425,736 R0 R971,562 


4% 8,597,172 40,839,530 19,619,406 7.03 

6% 6,141,106 39,698,376 14,014,476 8.75 

8% 4,639,940 38,612,958 10,588,699 10.60 



G2. Transfer of Mine Water to Bloemfontein 

Year Yield (m3/a) Capital O&M 

20,075,000 R633,000,000 R59,000,000 

1 2010 0.00 R300,000,000 0 

2 2011 0.00 R333,000,000 0 

3 2012 R20,075,000 R0 0 

4 2013 R20,075,000 R0 0 

5 2014 R20,075,000 R0 0 

6 2015 20,075,000 R0 R59,000,000 

7 2016 20,075,000 R0 R59,000,000 

8 2017 20,075,000 R0 R59,000,000 

9 2018 20,075,000 R0 R59,000,000 

10 2019 20,075,000 R0 R59,000,000 

11 2020 20,075,000 R0 R59,000,000 

12 2021 20,075,000 R0 R59,000,000 

13 2022 20,075,000 R0 R59,000,000 

14 2023 20,075,000 R0 R59,000,000 

15 2024 20,075,000 R0 R59,000,000 

16 2025 20,075,000 R0 R59,000,000 

17 2026 20,075,000 R0 R59,000,000 

18 2027 20,075,000 R0 R59,000,000 

19 2028 20,075,000 R0 R59,000,000 

20 2029 20,075,000 R0 R59,000,000 

21 2030 20,075,000 R0 R59,000,000 

22 2031 20,075,000 R0 R59,000,000 

23 2032 20,075,000 R0 R59,000,000 

24 2033 20,075,000 R0 R59,000,000 

25 2034 20,075,000 R0 R59,000,000 

26 2035 20,075,000 R0 R59,000,000 

27 2036 20,075,000 R0 R59,000,000 

28 2037 20,075,000 R0 R59,000,000 

29 2038 20,075,000 R0 R59,000,000 

30 2039 20,075,000 R0 R59,000,000 

31 2040 20,075,000 R0 R59,000,000 

32 2041 20,075,000 R0 R59,000,000 

33 2042 20,075,000 R0 R59,000,000 

34 2043 20,075,000 R0 R59,000,000 



35 2044 20,075,000 R0 R59,000,000 

36 2045 20,075,000 R0 R59,000,000 

37 2046 20,075,000 R0 R59,000,000 

38 2047 20,075,000 R0 R59,000,000 

39 2048 20,075,000 R0 R59,000,000 

40 2049 20,075,000 R0 R59,000,000 

41 2050 20,075,000 R0 R59,000,000 

42 2051 20,075,000 R0 R59,000,000 

43 2052 20,075,000 R0 R59,000,000 

44 2053 20,075,000 R0 R59,000,000 

45 2054 20,075,000 R0 R59,000,000 

46 2055 20,075,000 R0 R59,000,000 

47 2056 20,075,000 R0 R59,000,000 

48 2057 20,075,000 R0 R59,000,000 

49 2058 20,075,000 R0 R59,000,000 

50 2059 20,075,000 R0 R59,000,000 


4% 393,391,506 596,338,757 1,004,791,375 4.07 

6% 279,613,994 579,387,682 681,420,314 4.51 

8% 209,788,164 563,271,605 486,205,702 5.00 





APPENDIX 4 

Groundwater Potential for Small Towns

Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area i 

EXECUTIVE SUMMARY 

GHT Consulting Scientists were appointed to undertake a groundwater potential study for each of the small 

towns (Wepener, Dewetsdorp, Reddersburg, and Edenburg) located within the Greater Bloemfontein study 

area. The purpose of the investigation was to identify local groundwater resources and evaluate the 

potential of utilising groundwater to meet the anticipated future increase in water requirements. Currently, 

all these small towns receive water from Bloem Water and only a small percentage of the bulk water 

requirements are met through groundwater. To date, groundwater supply in the small towns has been 

problematic as most of the local municipalities do not have the technical capacity to manage the well fields 

and it is easier to rely on Bloem Water to supply all potable water requirements. However, in order to meet 

future water requirements, groundwater may be the most feasible source of water, as the bulk water 

infrastructure to the town will limit the supply of water above the design capacity threshold. 

This report details the assessment and results for each of the small towns. For each of the towns, potential 

dolerite dykes have been identified which need to be further investigated. It should be noted that there was 

no information confirming if these structures are water bearing and if so what the true sustainable yields are 

of these structures, not the estimate yields, as well as the associated groundwater qualities. 

The study concluded that it is viable to further investigate the groundwater resources for each of the small 

towns. It is recommended that any future orientated groundwater exploration study at least include the 

following components: 

Geophysical siting of groundwater exploration boreholes; 

Percussion drilling of the boreholes; 

Aquifer test pumping of successfully drilled exploration boreholes according to DWA specifications to 

determine the sustainable yields of the newly drilled boreholes; 

Sampling of all successfully drilled boreholes to determine the groundwater quality of the local site 

aquifer; 

Aquifer test pumping analyses of data to calculate sustainable yields and pump schedules; and 

Compilation of a Geohydrological Report. 

Appendix 4 – Groundwater Potential Study for Small Towns June 2012

Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area ii 

TABLE OF CONTENTS 

Page No 

1. BACKGROUND ................................................................................................................ 1 

1.1 INTRODUCTION ............................................................................................................................ 1 

1.2 OBJECTIVES OF THE STUDY ...................................................................................................... 1 

2. GEOLOGY ......................................................................................................................... 3 

2.1 LITHOSTRATIGRAPHY AND DEPOSITION HISTORY ................................................................. 3 

2.2 INTRUSIVE KAROO DOLERITE ................................................................................................... 4 

2.2.1 Geometry, structure and mechanisms of emplacement of dolerite dykes .......................... 5 

2.3 GEOHYDROLOGICAL IMPLICATIONS OF GEOLOGY ................................................................ 6 

2.3.1 Sediments ......................................................................................................................... 6 

2.3.2 Dolerite intrusions .............................................................................................................. 7 

2.4 HYDROSTRATIGRAPHY OF THE BEAUFORT GROUP .............................................................. 7 

2.5 GENERAL AQUIFER INFORMATION ........................................................................................... 7 

3. WEPENER ....................................................................................................................... 11 

3.1 CLIMATE ..................................................................................................................................... 11 

3.2 GEOLOGY ................................................................................................................................... 11 

3.2.1 General aquifer information of the Wepener District ........................................................ 11 

3.3 GROUNDWATER POTENTIAL INVESTIGATION ....................................................................... 15 

3.3.1 Aerial photo interpretation ................................................................................................ 15 

3.4 AERIAL MAGNETIC DATA INTERPRETATIONS ........................................................................ 15 

3.4.1 The Magnetic Method ...................................................................................................... 15 

3.4.2 The Aerial Magnetic Method ............................................................................................ 15 

3.4.3 Results of the aerial magnetic data interpretation ............................................................ 16 

3.4.4 Geological map interpretations ........................................................................................ 16 

3.5 RECHARGE WATER BUDGET CALCULATIONS AND ESTIMATED THEORETICAL 

YIELDS OF POTENTIAL DYKE STRUCTURES .......................................................................... 19 

3.5.1 Recharge water budget calculations ................................................................................ 19 

3.6 ESTIMATION OF THEORETICAL POTENTIAL YIELD OF THE DOLERITE 

DYKE STRUCTURES .................................................................................................................. 24 

3.7 SUMMARY OF THE RESULTS – GROUNDWATER RESOURCE POTENTIAL OF THE 

INTRUSIVE DOLERITE STRUCTURES ...................................................................................... 25 

3.7.1 Cost estimate of developing the proposed borehole fields ............................................... 25 

3.8 DETERMINATION OF HIGH GROUNDWATER ABSTRACTION AREAS ................................... 26 

3.9 CONCLUSIONS AND RECOMMENDATIONS ............................................................................ 28 

4. DEWETSDORP ............................................................................................................... 33 

4.1 CLIMATE ..................................................................................................................................... 33 

4.2 GEOLOGY ................................................................................................................................... 33 

4.2.1 General aquifer information of the Dewetsdorp District .................................................... 33 

4.3 GROUNDWATER POTENTIAL INVESTIGATIONS ..................................................................... 37 


4.3.2 Results of the aerial magnetic data interpretation ............................................................ 37 



YIELDS OF POTENTIAL DOLERITE STRUCTURES .................................................................. 39 










Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area iii 

5. REDDERSBURG ............................................................................................................. 55 

5.1 CLIMATE ..................................................................................................................................... 55 

5.2 GEOLOGY ................................................................................................................................... 55 

5.2.1 General aquifer information for Reddersburg ................................................................... 55 



5.3.2 Results of the aerial data interpretation ........................................................................... 58 



YIELDS OF POTENTIAL DOLERITE STRUCTURES .................................................................. 62 


5.5 ESTIMATION OF THEORETICAL POTENTIAL YIELD OF THE DOLERITE STRUCTURES ...... 68 






6. EDENBURG .................................................................................................................... 78 

6.1 CLIMATE ..................................................................................................................................... 78 

6.2 GEOLOGY ................................................................................................................................... 78 

6.2.1 General aquifer information of the Edenburg District ....................................................... 78 



6.3.2 Results of the aerial data interpretation ........................................................................... 81 



YIELD OF POTENTIAL DOLERITE DYKE STRUCTURES ......................................................... 85 









7. REFERENCES .............................................................................................................. 101 


Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area iv 

TABLES 

Table 3.1. Summary of the average available recharge to the Dyke Groups. The assumption thus 

made is that the available recharge volume correlates roughly to the sustainable yield 

available from the Dolerite Dyke groups. .............................................................................. 20 

Table 3.2: Recharge Volume Calculation Scenarios for Dyke Group A ................................................. 20 

Table 3.3: Recharge Volume Calculation Scenarios for Dyke Group B ................................................. 21 

Table 3.4: Recharge Volume Calculation Scenarios for Dyke Group C ................................................. 21 

Table 3.5: Recharge Volume Calculation Scenarios for Dyke Group D ................................................. 21 

Table 3.6: Theoretically estimated Dyke Group yields or groundwater resource potential based 

on the geometric mean of sustainable yields of Karoo Borehole Fields, see assumption 

section below the table for further information regarding the calculations ............................. 25 

Table 3.7: Estimation of the Borehole Field Development Cost for the Dyke Groups. Note that 

the costing does not make provision for Surface Infrastructure such as Electrical 

Supply Lines and Pipeline Networks etc. .............................................................................. 26 

Table 3.8: Coordinates of the Identified Irrigation Pivots ....................................................................... 26 

Table 4.1: Summary of the Average Available Recharge to the Dyke Groups. The assumption 

thus made is that the Available Recharge Volume correlates roughly to the Sustainable 

Yield available from the Dolerite Dyke Groups...................................................................... 40 



Table 4.4. Recharge Volume Calculation Scenarios for Dyke Group C ................................................. 41 


Table 4.6: Recharge Volume Calculation Scenarios for Dyke Group E ................................................. 42 

Table 4.7: Recharge Volume Calculation Scenarios for Dyke Group F ................................................. 42 

Table 4.8: Theoretically Estimated Dyke Group Yields or Groundwater Resource Potential 

based on the Geometric Mean of Sustainable Yields of Karoo Borehole Fields, see 

assumption section below the table for further information regarding the calculations .......... 46 



Supply Lines and Pipeline Networks etc ............................................................................... 47 




Yield Available from the Dolerite Dyke Groups ..................................................................... 63 



Table 5.4: Recharge Volume Calculation Scenarios for Dyke Group C ................................................. 64 





based on the Geometric Mean of Sustainable Yields of Karoo Borehole Fields, 

see assumption section below the table for further information regarding the calculations ... 69 

Table 5.9: Estimation of the Borehole Field Development Cost for the Dyke Groups. 

Note that the Costing does not make provision for Surface Infrastructure 

such as Electrical Supply Lines and Pipeline Networks etc .................................................. 70 




Yield available from the Dolerite Dyke Groups...................................................................... 86 



Table 6.4: Recharge Volume Calculation Scenarios for Dyke Group C1 & C2 ...................................... 87 




Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area v 


Table 6.8: Theoretically Estimated Dyke Group Yields or Groundwater Resource Potential based 

on the Geometric Mean of Sustainable Yields of Karoo Borehole Fields, see 

assumption section below the table for further information regarding the calculations .......... 92 

Table 6.9: Estimation of the Borehole Field Development Cost for the Dyke Groups. Note that the 

Costing does not make provision for Surface Infrastructure such as Electrical 

Supply Lines and Pipeline Networks etc ............................................................................... 93 


FIGURES 

Figure 2.1: Schematic Areal Distribution of Lithostratigraphic Units in the Main Karoo Basin 

(after Johnson et al., 1997) ..................................................................................................... 3 

Figure 2.2: Generalised Stratigraphy and Lithology of the Karoo Supergroup of the Main Karoo Basin 

(Johnson et al., 1997) ............................................................................................................. 4 

Figure 2.3: Groundwater Component of River Flow (base flow), Groundwater Resources of 

South Africa, DWAF, 1995 ...................................................................................................... 8 

Figure 2.4: Depth of Groundwater Level, Groundwater Resources of South Africa, DWAF, 1995 ............ 9 

Figure 2.5: Mean Annual Recharge, Groundwater Resources of South Africa, DWAF, 1995 ................. 10 

Figure 2.6: Groundwater Recharge Estimation Map (Vegter, 1995) ....................................................... 10 

Figure 3.1: Locality Map of the Wepener Study Area .............................................................................. 12 

Figure 3.2: Geological Map of the Wepener Study Area ......................................................................... 13 

Figure 3.3: Locality Map of the Aerial Photo Interpretations of the Wepener Study Area ........................ 14 

Figure 3.4: Aerial Magnetic Data Contour Map for the Wepener Area. Note that the red and yellow 

areas denote areas of Higher Magnetic Intensity that are associated with Dolerite Sill 

Intrusions. The green and blue areas refer to Sedimentary Rocks of the Beaufort Group 

(Karoo Supergroup) .............................................................................................................. 17 

Figure 3.5: Geological Map of the Wepener Study Area. The Geological Map confirms the 

presence of at least 31 Potential Dolerite Dykes as determined by the Aerial 

Photo Interpretations ............................................................................................................ 18 

Figure 3.6: Locality Map of the Delineated Dolerite Dyke Groups near Wepener as utilised for the 

Groundwater Resource Potential Estimation ........................................................................ 22 

Figure 3.7: Locality Map of the Estimated Mini-Catchments of the Dyke Groups near Wepener ............ 23 

Figure 3.8: Locality Map of the Potential High Groundwater Abstraction Areas in the vicinity of 

Wepener. Note that the Irrigation Pivots are situated next to the Caledon River. 

Therefore it is more likely that these pivots utilised Surface Water than Groundwater. 

It is recommended that these areas be investigated to confirm the observation ................... 27 

Figure 4.1: Locality Map of the Dewetsdorp Study Area ......................................................................... 34 

Figure 4.2: Geological Map of the Dewetsdorp Study Area .................................................................... 35 

Figure 4.3: Locality Map of the Aerial Photo Interpretations of the Dewetsdorp Study Area ................... 36 

Figure 4.4: Aerial Magnetic Data Contour Map for the Dewetsdorp Area. Note that the red and yellow 

areas denote areas of Higher Magnetic Intensity that are associated with Dolerite Sill 

Intrusions. The green and blue areas refer to Sedimentary Rocks of the Beaufort Group 

(Karoo Supergroup) .............................................................................................................. 38 

Figure 4.5: Locality Map of the Delineated Dolerite Dyke Groups near Dewetsdorp as utilised for the 


Figure 4.6: Locality Map of the Estimated Mini-Catchments of the Dyke Groups near Dewetsdorp ........ 44 


Dewetsdorp. Note that the Irrigation Pivots are situated next to Non-Perennial Streams 

and Small Dams. Therefore it is more likely that these Pivots utilised Surface Water 

than Groundwater. It is recommended that these areas be investigated to confirm 

the observation ..................................................................................................................... 49 

Figure 5.1: Locality Map of the Reddersburg Study Area ....................................................................... 56 

Figure 5.2: Geological Map of the Reddersburg Study Area ................................................................... 57 

Figure 5.3: Locality Map of the Aerial Photo Interpretations of the Reddersburg Study Area .................. 59 


Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area vi 

Figure 5.4: Aerial Magnetic Data Contour Map for the Reddersburg Area. Note that the red 

and pinkish / purple areas denote areas of Higher Nagnetic Intensity that are associated 

with Dolerite Sill Intrusions. The green and blue areas refer to Sedimentary Rocks 

of the Beaufort Group (Karoo Supergroup) ........................................................................... 60 

Figure 5.5: Geological Map of the Reddersburg Study Area. The Geological Map confirms the 

presence of at least 52 Potential Dolerite Dykes as determined by the Aerial Photo 

Interpretations ....................................................................................................................... 61 

Figure 5.6: Locality Map of the Delineated Dolerite Dyke Groups near Reddersburg as utilised 

for the Groundwater Resource Potential Estimation ............................................................. 66 

Figure 5.7: Locality Map of the estimated Mini-Catchments of the Dyke Groups near Reddersburg ...... 67 


Reddersburg. Note that the Irrigation Pivots are situated next to the Riet River and 

other Non-Perennial Streams. Therefore it is more likely that these Pivots utilised Surface 

Water than Groundwater. It is recommended that these areas be investigated to confirm 

the observation ..................................................................................................................... 72 

Figure 6.1: Locality Map of the Edenburg Study Area ............................................................................. 79 

Figure 6.2: Geological Map of the Edenburg Study Area ........................................................................ 80 

Figure 6.3: Locality Map of the Aerial Photo Interpretations of the Edenburg Study Area ....................... 82 

Figure 6.4: Aerial Magnetic Data Contour Map for the Edenburg Area. Note that the yellow, red 

and pinkish / purple areas denote areas of higher magnetic intensity that are associated 

with Dolerite Sill Intrusions. The light green and blue areas refer to sedimentary 

rocks of the Adelaide Subgroup of the Beaufort Group (Karoo Supergroup) ........................ 83 

Figure 6.5: Geological Map of the Edenburg Study Area. The Geological Map confirms the 

Presence of at least 36 Potential Dolerite Dykes as determined by the Aerial Photo 

Interpretations ....................................................................................................................... 84 

Figure 6.6: Locality Map of the Delineated Dolerite Dyke Groups near Edenburg as utilised for the 


Figure 6.7: Locality Map of the Estimated Mini-Catchments of the Dyke Groups near Edenburg ........... 90 

Figure 6.8: Locality Map of the Potential High Groundwater Abstraction Areas in the Vicinity of 

Edenburg. Note that the Irrigation Pivots are situated next to the Riet River and other 

Non-Perennial Streams. Therefore it is more likely that these Pivots utilised Surface 

Water than Groundwater. It is recommended that these areas be investigated to 

confirm the observation ........................................................................................................ 95 


Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area vii 

GLOSSARY OF TERMS 

GEOHYDROLOGICAL TERMS DEFINITIONS 

Aquiclude, 

Aquitards, 

Confined Aquifer, 

Diffusivity (KD/S), 

Hydrocensus, 

Hydraulic Conductivity (K), 

Leaky Aquifer, 

Porosity, 

Specific Yield (Sy), 

Storativity (S), 

Storativity Ratio, 

Sustainable Yield, 

Transmissivity (KD or T), 

Unconfined Aquifer, 

Recharge, 

An aquiclude is an impermeable geological unit that does not transmit water at all. Dense 

unfractured igneous or metamorphic rocks are typical aquicludes. 

An aquitard is a geological unit that is permeable enough to transmit water in significant 

quantities when viewed over large and long periods, but its permeability is not sufficient to 

justify production boreholes being placed in it. Clays, loams and shales are typical aquitards. 

A confined aquifer is bounded above and below by an aquiclude. In a confined aquifer, the 

pressure of the water is usually higher than thatt of the atmosphere, so that if a borehole taps 

the aquifer, the water in it stands above the top of the aquifer, or even above the ground 

surface. We then speak of a free-flowing or artesian borehole. 

The hydraulic diffusivity is the ratio of the transmissivity and the storativity of a saturated 

aquifer. It governs the propagation of chances an hydraulic head in the aqiufer. Diffusivity 

has the dimension of Length 2 /Time. 

A field survey by which all relevant information regarding groundwater is amassed. This 

typically includes yields, borehole equipment, groundwater levels, casing height / diameter, 

WGS84 coordinates, potential pollution risks, photos etc. 

The hydraulic conductivity is the constant of proportionality in Darcy’s law. It is defined as 

the volume of water that will move through a porous meduim in a unit time under a unit 

hydraulic gradient through a unit area measured at right angles to the direction of flow. 

A leaky aquifer, also known as a semi-confined aquifer, is an aquifer whose upper and lower 

boundaries is aquitards, or one boundary is an aquitard and the other is an aquiclude. Water 

is free to move through the aquitards, either upwards or downwards. If a leaky aquifer is in 

hydrological equilibrium, the waterlevel in a borehole tapping it may coincide with the water 

table. 

The porosity of a rock is its property of containing pores or voids. With consolidated rocks 

and hardrocks, a distinction is usually made between primary porosity, which is present when 

the rock is formed and secondary porosity, which develops later as a result of solution or 

fracturing. 

The specific yield is the volume of water that an unconfined aquifer releases from storage per 

unit surface area of aquifer per unit decline of the water table. The values of the specific yield 

range from 0.01 to 0.3 and are much higher than the storativities of confined aquifers. 

The storativity of a saturated confined aquifer of thickness D is the volume of water released 

from storage per unit surface area of the aquifer per unit decline in the component of hydraulic 

head normal to that surface. 

The storativity ratio is a parameter that controls the flow from the aquifer matrix blocks into 

the fractures of a confined fractured aquifer of the double-porosity type. 

This usually refers to a yield calcualted from aquifer test pumping by a professional 

geohydrologist. The yield refers to the recommended abstraction rate and pumping schedule 

for continues use. 

Transmissivity is the product of the average hydraulic conductivity K and the saturated 

thickness of the aquifer D. Consequently, transmissivity is the rate of flow under a unit 

hydraulic gradient throught a cross-section of unit width over the whole saturated thickness 

of the aquifer. 

An unconfined aquifer, also known as a water table aquifer, is bounded below by a aquiclude, 

but is not restricted by any confining layer above it. Its upper boundary is the water table 

and is free to rise and fall. 

Groundwater recharge or deep drainage or deep percolation is a hydrologic process where 

water moves downward from surface water to groundwater. This process usually occurs in 

the vadose zone below plant roots and is often expressed as a flux to the water table surface. 

Recharge occurs both naturally (through the water cycle) and anthropologically (i.e., "artificial 

groundwater recharge"), where rainwater and or reclaimed water is routed to the subsurface. 


Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area viii 

Acronym / Abbreviation Definition 

CRD Cumulative Rainfall Departure. 

DWAF Department of Water Affairs and Forestry. 

GHT Geo-Hydro Technologies. 

magl Metres Above Ground Level. 

MAP Mean Annual Precipitation. 

mbgl Metres Below Ground Level. 

mamsl Metres Above Mean Sea level. 

SVF Saturated Volume Fluctuation. 

TOR Terms of Reference. 

VIP’s Ventilated In-Pit Latrines. 

WRC Water Research Commission. 

P:\Projects\402992 Bloem Recon\FINAL REPORTS\Appendix 4 - Groundwater Potential for Small Towns.docx 


Water Reconciliation Strategy Study for the Bulk Water Supply Systems: Greater Bloemfontein Area 1 

1. BACKGROUND 

1.1 INTRODUCTION 

GHT Consulting was appointed by Aurecon and the Department of Water Affairs to perform a groundwater 

potential study for the small towns located within the study area. Groundwater potential for urban use was 

considered in the following towns: 

Wepener 

Dewetsdorp 

Reddersburg 

Edenburg 

Excelsior 

1.2 OBJECTIVES OF THE STUDY 

The objectives of the groundwater potential study are as follows: 

GIS geological maps (Geological Survey) will be employed to determine possible water bearing 

structures / lineaments for a 10 - 15 km radius around the towns 

Aerial photo interpretations to determine possible water bearing structures / lineaments for a 10 - 15 

km radius around the towns; 

GIS Ortho photos or will be employed to identify potential dolerite dykes structures, which 

are the primary drilling targets for groundwater resource development in the Karoo Super 

Group geology. 

Aerial magnetic interpretations to determine potential water bearing structures / lineaments for a 10 - 

15 km radius around the towns. 

GIS aerial magnetic data obtained from the Council for Geosciences will be employed to 

identify potential intrusive dolerite structures such as sills and dykes, which are the primary 

drilling targets for groundwater resource development in the Karoo Super Group geology. 

GIS map compilation wherein the identified potential water bearing structures are geo-referenced 

and denoted spatially; 

The Map Info Professional 7.5 GIS Packaged will be utilised in the compilation of the 

necessary locality maps. 

Determination of high groundwater abstraction areas in the vicinity of the identified town by means of 

a hydrocensus; and 

High groundwater abstraction areas will be determined around the towns by means aerial 

photographs, which include Google Earth Images and Ortho Photos. The typical features 

that will be observed are large scale irrigation in the absence of perennial rivers. Note that 

no field surveys will be employed due to budget constraints. 

Recharge volume estimation will be calculated based on a surface area approach assuming a 2%, 

3% as well as the Vegter Map recharge percentage and DWAF estimates maps of 1995. Mini subcatchments 

will be identified in the areas of the observed potential structures by means of 

topographical contours. The surface area of these mini sub-catchments will be incorporated to 

calculate the recharge volume to the potential structure(s). The water demand for each town will be 

obtained from Aurecon to determine the recharge area needed to address demand. 



Compilation of a Geohydrological Report, which will contain all the information generated during the 

study as well as conclusions and recommendations regarding the groundwater potential of the area. 

Note that this is a desktop study and that no fieldwork is included in the terms of reference or in the 

costing. 



2. GEOLOGY 

This section contains the general geology, geological logging and soil characteristics information collected 

during the completion of the project. 

2.1 LITHOSTRATIGRAPHY AND DEPOSITION HISTORY 

This section has been adapted from the Hydrogeology of the Main Karoo Basin, WRC Report No. 

TT179/02. The lithostratigraphy of the Arlington / Leratswana district consists of the following: 

Karoo Supergroup (refer to Figure 2.1); 

Beaufort Group (Upper Stage, which comprises of sedimentary rocks such as purple and green shale 

and mudstone). 

Figure 2.1: Schematic Areal Distribution of Lithostratigraphic Units in the Main Karoo Basin 

(after Johnson et al., 1997) 



Figure 2.2: Generalised Stratigraphy and Lithology of the Karoo Supergroup of the Main Karoo 

Basin (Johnson et al., 1997) 

2.2 INTRUSIVE KAROO DOLERITE 

Towards the end of the Cape Orogeny a thermal dome uplift developed beneath almost the entire South 

African continent. Dolerite intrusions represent the roots of the volcanic system and are presumed to be of 

the same age as the extrusive lavas (Fitch and Miller, 1984). Extensive magmatic activity lead to dolerite 

dykes, inclined sheets and sills to intrude the sedimentary rocks of the Karoo Supergroup during the 

Jurassic period to the north of the compressional sphere of the Cape Fold Belt. The level of erosion that 

affected the Main Karoo basin has revealed the deep portions of the intrusive system, which displays a high 

degree of tectonic complexity. The Karoo intrusives can either occur as dykes (linear features), sills 

(horizontal or inclined sheets) or ring-complexes. The Karoo dolerite, which includes a wide range of 

petrological facies, consists of an interconnected network of dykes and sills and it is nearly impossible to 

single out any particular intrusive or tectonic event. It would, however, appear that a very large number of 

fractures were intruded simultaneously by magma and that the dolerite intrusive network acted as a shallow 

stockwork-like reservoir. 

Early mapping of the dolerite intrusives was carried out by Rogers and Du Toit (1903) in the Western Cape 

and Du Toit (1905) in the Eastern Cape. Further contributions on their tectonic and structural aspects 

include Du Toit (1920), Mask (1966) and Walker and Poldervaart (1949). More recently the Geological 

Survey has published most of the 1:250 000 maps of the entire Karoo Basin. Detailed mapping of dolerite 

occurrences at specific localities in the southern Free State were conducted by Burger et al., (1981) and in 

the Western Karoo by Chevallier and Woodford (1999). 



In the study areas sills are the most abundant dolerite appearance and may be horizontal or slightly 

inclined. Geophysical data indicated also the presence of dyke structure although very few in number. 

2.2.1 Geometry, structure and mechanisms of emplacement of dolerite dykes 

Dolerite dykes are the primary targets for groundwater exploration and it is therefore important to 

understand the geometry, structure and mechanisms of emplacement. 

Emplacement Mode: Dolerite dykes, like many other magmatic intrusions, develop by rapid hydraulic 

fracturing via the propagation of a fluid-filled open fissure, resulting in a massive magmatic intrusion with a 

neat and transgressive contact with country rock. This fracturing mechanism is in contrast to the slow 

mode of hydraulic fracturing responsible for breccia-intrusions (i.e. kimberlite). For the intrusion to develop 

the magma pressure at the tip of the fissure must overcome the tensile strength of the surrounding rock. 

Dykes can develop vertically upwards or lateral along-strike over very long distances, as long as the 

magma pressure at the tip of the fissure is maintained. The intrusion of dolerite and basaltic dykes are 

therefore never accompanied by brecciation, deformation or shearing of the host-rock, at least during their 

propagation. 

Dyke Attitude: All the dykes are sub-vertical with a dip rarely below 70 degrees. Kruger and Kok (1976) 

reports dips of dykes in the north eastern Free State varying between 65 to 90 degrees. The attitude of 

dykes often change with depth (i.e. are curved or dislocated), as observed from many detailed borehole 

logs. This phenomenon can be attributed to vertical offsetting as a result of vertical en-échelon 

segmentation or due to interconnecting of dykes between sediment layers. 

Dyke Width: The average thickness of Karoo dolerite dykes ranges between 2 and 10 m (Woodford and 

Chevallier, 2001). In general, the width of a dyke is a function of its length. In other words, the wider a 

dyke is, the longer it will be (this probably also applies to the vertical extension of the feature). For 

example, the major E-W dykes of Western Karoo Domain can attain widths of up to 70 m, while the 

Middelburg dyke is 80 m wide. The radiating E-W dykes of Eastern Karoo have widths of up to 300 m in 

places. No relationship has been found between trend and thickness (Woodford and Chevallier, 2001). 

En-échelon Pattern: Dolerite dykes often exhibit an en-échelon pattern along strike, which are clearly 

detected by mapping. This is especially the case with the E-W shear dykes and their associated riedelshears. 

Displacements in the vertical section also occur, often associated with horizontal, transgressive 

fracturing. These offsets are often observed, except through drilling. 

Dyke Related Fracturing: The country rock is often fractured during and after dyke emplacement. These 

fractures form a set of master joints parallel to its strike over a distance that does not vary greatly with the 

thickness of the dyke (between 5 and 15 m). The dolerite dykes are also affected by thermal- or columnar- 

jointing perpendicular to their margins. These thermal joints also ex tends into the host rock over a 

distance not exceeding 0.3 to 0.5 m from the contact. Van Wyk (1963) observed two types of jointing 

associated with dyke intrusions in a number of coal mines in the Vryheid Dundee area, namely: 

Three sets of pervasive-thermal, columnar joints that are approximately 120 degrees apart; and 

Joints parallel to the contact, confined mainly to the host rock alongside the dyke. 

Many cases of tectonic reactivation of the dolerite have been observed in the Loxton-Victoria West area 

(Woodford and Chevallier, 2001), especially on the N-S dykes that have been reactivated by cretaceous 

kimberlite activity or by more recent master jointing. Reactivation often results in sub-vertical fissures within 

the country rock and/or dyke itself, which are commonly highly weathered and filled with secondary 

calcite/calcrete (width of up to 150 mm) uplifting or brecciation of the sediment along the dyke contact. 

Deformation and Contact Metamorphism of Host Rock: Localised upwarping of the country rock is often 



observed adjacent to dipping dykes. Hydraulic fissure propagation, as mentioned above, cannot be 

responsible for this phenomena, as the magma would have to be cool and become viscous in order cause 

such deformation. This upwarping of the country rock is commonly a near-surface phenomenon related to 

supergene formation of clays with a high expansion coefficient resulting in the ‘swelling’ of rock mass. In 

nearly every case, the dolerite magma shows marked chilling against the sediments into which it has been 

injected. The chill zone generally exhibits the effects of contact metamorphism, where argillites are altered 

to hornfels or lydianite and arenaceous units are crystallised to quartzite. Enslin (1951) and Van Wyk 

(1963) state that the jointed contact zone is less than 30 c wide, irrespectively of dyke thickness. 

Petrography and Dyke Weathering: The effect of variable cooling of dykes following intrusion is also 

apparent in the way which dykes weather in the Western Karoo, namely: 

Thick dykes (>8 m) generally exhibit a prominent chill-margin containing a fine grained, porphyritic, 

melanocratic dolerite that weathers to produce well-rounded, small, white-speckled boulders (i.e. 

spheroidal weathering). This zone is normally only 0.5 to 1.5 m wide and exhibits well-developed 

thermal-shrinkage joints. The central portion of such dykes consist of medium to coarse grained, 

mesocratic and occasionally leucocratic dolerite that decomposes to a uniform ‘gravely’ material, 

which exhibits an exfoliation type of pattern. Sporadic fractures or meta-sedimentary veins are 

encountered in this zone and they often do not extend into the country rock. Magnetic traverses 

across these features normally produce two distinctive peaks. 

Thin dykes (


2.3.2 Dolerite intrusions 

Extensive weathered zones often develop in dolerite sills that are situated in low lying and well drained 

areas – ‘similar to weathered basins’ described in other crystalline basement rocks (Enslin, 1943; Wright 

and Burgess, 1992). These localised, shallow intergranular aquifers are capable of storing large volumes 

of groundwater. Although abstraction from these dense-massive structures are only possible where 

extensive weathering has occurred at depth (below the aquifer water table). 

Dolerite ring-dykes and inclined sheets seldom form negative features of the landscape, as they are more 

resistant to weathering. The hydrological properties weathered dolerite rings and inclined sheets seem 

very variable. Vegter (1995) states that the upper or lower contact sills located within the weathered zone, 

i.e. 20 to 50 mbgl, are favourable zones for striking groundwater. Recent extensive exploration drilling 

along dolerite inclined sheets and ring dykes in the Victoria West area (Chevallier et al., 2001), shows that 

the contact between the sediment and the dolerite within the first 50 m below surface did not yield 

significant volumes of groundwater. 

The contact between dolerite dykes and the host rock, within the weathered zone, remains the most 

important target for groundwater exploration (Vegter, 1995 & Smart, 1998). 

2.4 HYDROSTRATIGRAPHY OF THE BEAUFORT GROUP 

The main sediment source area for the Beaufort rocks lay along the high-lying, southern margin of the 

Basin. The coarser grained rocks are, therefore, found near the Cape Fold Belt (alluvial fan and braided 

stream environments), while mudstone, shale and fine-grained sandstones dominate the more distal central 

and northern portion (meandering river and floodplain environment) of the Basin. The sedimentary units in 

the Group therefore usually have very low primary permeabilities. The geometry of these aquifers is 

complicated by the lateral migration of meandering streams over a floodplain. Aquifers in the Beaufort 

Group will thus not only be multi-layered, but also multi-porous with variable thicknesses. 

The contact plane between two different sedimentary layers will cause a discontinuity in the hydraulic 

properties of the composite aquifer. The pumping of a multi-layered aquifer will thus cause the piezometric 

pressure in the more permeable layers to drop faster than in the less permeable layers. It is therefore 

possible to completely extract the more permeable layers of the multi-layered Beaufort aquifers, without 

materially affecting the piezometric pressure in the less permeable layers. This complex behaviour of 

aquifers in the Beaufort Group is further complicated by the fact that many of the coarser, and thus more 

permeable, sedimentary bodies are lens-shaped. The life-span of a high-yielding borehole in the Beaufort 

Group may therefore be limited, if the aquifer is not recharged frequently. 

2.5 GENERAL AQUIFER INFORMATION 

The following section is based on the Groundwater Resources of South Africa Maps, DWAF, 1995. The 

groundwater component of river flow (base flow) is 0 – 10 mm/a in the Wepener district (refer to Figure 

2.3). The groundwater depth in the study area is approximately 10 – 20 mbgl (standard deviation range 

from mean is between 8 – 15 m), refer to Figure 2.4. The mean annual recharge of the area are between 

25 - 37 mm/a (refer to Figure 2.5). In general the recommended drilling depths are 20 to 30 metres or 

deeper for the study area. The storage types of the aquifer quantified as fractures restricted principally to a 

zone below the groundwater level. Pores in disintegrated / decomposed, partly decomposed rock and 

fractures which are principally restricted to a zone directly below the groundwater level. Storage coefficient 

in order of magnitude for the study area is 0.001 to 0.01. 



Figure 2.3: Groundwater Component of River Flow (base flow), Groundwater Resources of 

South Africa, DWAF, 1995 



Figure 2.4: Depth of Groundwater Level, Groundwater Resources of South Africa, DWAF, 1995 



Figure 2.5: Mean Annual Recharge, Groundwater Resources of South Africa, DWAF, 1995 

Figure 2.6: Groundwater Recharge Estimation Map (Vegter, 1995) 



3. WEPENER 

The study area is located in the north eastern part of the Free State Province in Water Management Area 

13. The study area is also located in Drainage Area D, Quaternary sub-catchment D23G and D23J 

(Surface Water Resources of South Africa, First Edition, 1994). The locality map of the Wepener study area 

can be viewed in Figure 3.1. 

3.1 CLIMATE 

The investigated area has hot summers and cool winters, and a predominantly summer rainfall. The air 

temperatures range from an average maximum of 30 to 32 o C in January to an average minimum of 0 to 2 

o C in July, meaning conditions with hot summers and cold winters (South African Atlas of Agrohydrology 

and –Climatology, 1997). 

Wepener has no rainfall station, therefore the rainfall for Dewetsdorp is assumed for Wepener. Dewetsdorp 

is located approximately 35 km away from Wepener in a north westerly direction. The mean annual rainfall 

is 592.7 mm/a, which occurs mainly as thunderstorms but soft rains also do occur (Rainfall Station Gauge 

No.: 0232 275, Dewetsdorp Police Station, Surface Water Resources of South Africa, 1990). 

3.2 GEOLOGY 

3.2.1 General aquifer information of the Wepener District 

The following section is based on the Groundwater Resources of South Africa Maps, DWAF, 1995. 

The groundwater component of river flow (base flow) is 0 – 10 mm/a in the Wepener district (refer to 

Figure 2.3). The groundwater depth in the study area is approximately 10 – 20 mbgl (standard deviation 

range from mean is between 8 – 15 m), refer to Figure 2.4. The mean annual recharge of the area are 

between 25 - 37 mm/a (refer to Figure 2.5). 

In general the recommended drilling depths are 20 to 30 metres or deeper for the study area. The storage 

types of the aquifer quantified as fractures restricted principally to a zone below the groundwater level. 

Pores in disintegrated / decomposed, partly decomposed rock and fractures which are principally restricted 

to a zone directly below the groundwater level. Storage coefficient in order of magnitude for the study area 

is 0.001 to 0.01. 



Figure 3.1: Locality Map of the Wepener Study Area 



Figure 3.2: Geological Map of the Wepener Study Area 



Figure 3.3: Locality Map of the Aerial Photo Interpretations of the Wepener Study Area 



3.3 GROUNDWATER POTENTIAL INVESTIGATION 

This section includes the geophysical information obtained during the survey to detect possible geological 

features and structures, which may act as preferential pathways for groundwater flow, which may act as 

target areas for groundwater exploration for water supply purposes. 

3.3.1 Aerial photo interpretation 

The aerial photo interpretation of the Wepener study area revealed 31 potential dolerite dyke structures that 

can be verified by means of geophysical methods and percussion drilling. The dolerite dyke structures are 

considered the primary targets for groundwater exploration in the Karoo Supergroup geology. The aerial 

photo map of the study area can be viewed in Figure 3.3. 

3.4 AERIAL MAGNETIC DATA INTERPRETATIONS 

3.4.1 The Magnetic Method 

The magnetic geophysical method proved an effective method for the detection of dolerite structures, which 

includes dykes and sills. 

The normal magnetic field of the earth can be visualised as a field of a bar magnet placed at the centre of 

the earth. Any changes in this "normal" magnetic field superimposed by dykes, for example, can be 

measured by a magnetometer. These measurements (changes) in magnetism can then, through the 

process of modelling, be interpreted in terms of the dip, strike, depth and width of the body that causes the 

anomaly. Since these geological magnetic features might be remnant (i.e. permanently) magnetised, a 

feature, which is normally not known to the modeller, no unique solution of the model exists. By making 

certain reasonable assumptions about the geology, restrictions can be placed on some of the geological 

features of the body. The magnetic method is an extremely useful method to map of dykes, which are good 

groundwater exploration targets. 

3.4.2 The Aerial Magnetic Method 

Airborne magnetic surveys can encompass large areas in a relatively short period of time, using helicopters 

or low flying aircraft trailing a magnetometer. Although these surveys do not have the same spatial 

resolution of ground surveys, they are invaluable for tracing larger structural features, and especially major 

dyke intrusions into the Karoo sediments. The entire Karoo basin has been covered by aeromagnetic 

surveys, which were carried out on behalf of the Council for Geoscience and are available on digital format. 

Airborne magnetometers all measure the total magnetic field and are of two main types, fluxgate 

magnetometers and proton magnetometers. The fluxgate magnetometer which measures the field relative 

to a selected datum uses two systems of coils, one, much as in ground magnetometers, measures the 

relative field, while the second system of coils together with associate electronics and motor driven gimbals 

maintains the measuring coil in the direction of the total magnetic field irrespective of aircraft heading and 

attitude. The proton magnetometer measures the absolute value of the total field and needs no 

sophisticated orient mechanism. Proton magnetometers are favoured in most recent installations. There 

are other more sensitive magnetometers used in petroleum surveys. 

The sensing head of the magnetometer is either carried in an extended “stinger” on the tail, mounted on the 

wingtip or is towed in a “bird” to keep the measuring elements away from the magnetic influence of the 

aircraft. 

Magnetic data is recorded continuously during flight on a paper recorder, magnetic tape or electronically. 

The flight path of the aircraft is recorded by photographing the ground traversed with a special 35 mm 



camera. Numbered timing marks, known as fiducials, are recorded on both the film and on the paper 

record (or magnetic tape) on which the magnetic data appears. A radio altimeter records the aircraft height 

above ground and feeds height information to the pilot. The aircraft is navigated with the aid of existing 

aerial photographs, large scale maps or by using electronic navigational aids. The sensitivity of the 

airborne magnetometers is in the order of 0.5 to 1 nT. 

3.4.3 Results of the aerial magnetic data interpretation 

The aerial magnetic map revealed numerous dolerite sill intrusions in the study area (refer to Figure 3.4). 

The study area is located on the sedimentary rocks of the Beaufort Group of the Karoo Supergroup. The 

green and blue areas on the aerial magnetic contour map denote sedimentary rocks. Dolerite intrusives 

such as dykes and sill structures are denoted as the red and yellow areas of the aerial magnetics map. 

The available aerial magnetic data available for the study area are of a low resolution, which brings about 

that the smaller dolerite dyke structures occurring within the area cannot be detected due to the spacing of 

the flight lines for the aerial magnetic survey. The potential dolerite dykes denoted on the aerial magnetics 

map was determined by means of aerial photo interpretations as well as geological maps. 

3.4.4 Geological map interpretations 

The geological map interpretation of the Wepener study area revealed 31 potential dolerite dyke structures, 

which confirms the aerial photo interpretations, which also indicated the potential presence of these dolerite 

structures. The aerial photo map of the study area can be viewed in Figure 3.5. 



Figure 3.4: Aerial Magnetic Data Contour Map for the Wepener Area. Note that the red and yellow areas denote areas of Higher Magnetic Intensity that are associated with Dolerite Sill Intrusions. The green and blue areas 

refer to Sedimentary Rocks of the Beaufort Group (Karoo Supergroup) 



Figure 3.5: Geological Map of the Wepener Study Area. The Geological Map confirms the presence of at least 31 Potential Dolerite Dykes as determined by the Aerial Photo Interpretations 



3.5 RECHARGE WATER BUDGET CALCULATIONS AND ESTIMATED 

THEORETICAL YIELDS OF POTENTIAL DYKE STRUCTURES 

The following section evaluates the theoretical groundwater resource potential of the identified potential 

dolerite dyke structures by means of recharge water budget calculations based on potential minicatchments 

of dolerite dyke groups as well as theoretical yields of the structures based on average 

sustainable yield calculations by means of aquifer test pumping of borehole fields in the Karoo Super Group 

geology. 

Note that these resource potential calculations are only rough approximations of the potential sustainable 

yield volumes. The only method of determining the sustainable yield volume of a dolerite structure(s) is by 

geophysical siting, percussion drilling and aquifer test pumping of the borehole(s). Long-term groundwater 

monitoring is also important to observed and understand the aquifer dynamics. After sufficient data is 

generated a numerical model flow may be constructed to determine the capture zones of the individual 

boreholes as well as the capture zone of the well field as a whole. 

3.5.1 Recharge water budget calculations 

The estimate recharge volume scenarios are based on a 2% and a 3% recharge percentages of the annual 

mean rainfall (592.7 mm/a, Surface Water Resources of South Africa, 1990) as well as recharge 

estimations according to the Groundwater Resources of South Africa (DWAF, 1995) and the Vegter 

Recharge Map (1995). The recharge maps can be viewed in Figure 2.5 and Figure 2.6. 

It must be noted that the recharge volume calculations are only estimates of recharge to the estimated minicatchments 

of the dyke groups as delineated in Figure 3.6 and Figure 3.7. The aim of the recharge 

volume calculations is to estimate the available recharge volume available to the dyke groups in the study 

area. The assumption thus made is that the available recharge volume correlates roughly to the 

sustainable yield available from the dolerite dyke groups. This method is only a rough approximation of 

potential sustainable yields due to that the sustainability of the intrusive structure is a function of the capture 

zone, which in turn entails the dynamics of the aquifer system (The Water budget Myth Revisited; Why 

Hydrogeologists Model, Bredehoeft, 2002). The main tool for investigating the capture zone and aquifer 

dynamics is the numerical groundwater model. Unfortunately not enough geohydrological information 

exists in terms of aquifer parameters to construct such a model. Therefore only rough estimation can be 

made regarding the groundwater resource potential. 

The results of the groundwater resource potential estimations based on recharge volume scenarios are as 

follows (the summary of the recharge volumes can be studied in Table 3.1): 

Estimated groundwater resource potential is estimated for Dyke Group A as approximately 658 m 3 /d 

(refer to Table 3.2). 

Estimated groundwater resource potential is estimated for Dyke Group B as approximately 7 651 

m 3 /d (refer to Table 3.3). 

Estimated groundwater resource potential is estimated for Dyke Groups C as approximately 743 m 3 /d 


Estimated groundwater resource potential is estimated for Dyke Group D as approximately 1 370 


The estimated high growth scenario for the average annual daily water demand for Wepener was 

obtained from Aurecon and is 2 871 m 3 /d or kl/d. The estimated recharge area needed to address 

the above demand is approximately 30.4 km 2 . 



Table 3.1. Summary of the average available recharge to the Dyke Groups. The assumption 

thus made is that the available recharge volume correlates roughly to the 

sustainable yield available from the Dolerite Dyke groups. 

Dyke Group Name 

Average Recharge Available To Dyke Groups 

Estimation of Recharge Volume 

(m 3 /a) 


(m 3 /d) 

Dyke Group A 240 186 658 

Dyke Group B 2 792 741 7 651 

Dyke Group C 271 132 743 

Dyke Group D 499 899 1 370 

Total 3 803 959 10 422 

Assumptions: 

* Note that the recharge volume calculations are a function of the mean annual rainfall of the area, 

recharge percentage assigned and the surface area of the dyke group catchment. Also note that the 

estimated available recharge to the aquifer is only available for abstraction purposes if sufficient 

dolerite dykes structures and associated fractures are available in geology of the site aquifer. 

* Note the average recharge volumes in this table are based on the recharge percentages as obtained 

from the Vegter Maps and DWAF Groundwater Resources of South Africa Maps. 

Table 3.2: Recharge Volume Calculation Scenarios for Dyke Group A 

Dyke Group 

Name 

Dyke Group A 

Assumptions: 

Recharge Scenario 

Estimation of Dyke 

Group Catchment Area 

(m 2 ) 

Average Rainfall 

(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Estimation of 

Recharge Volume 

(m 3 /a) 

Estimation of 


(m 3 /d) 

2% Recharge 6 962 000 592.7 2.0 12 82 528 226 

3% Recharge 6 962 000 592.7 3.0 18 123 791 339 

Vegter Map Recharge, 

(32 mm/a) 

DWAF, Groundwater 

Resources of SA Recharge (37 mm/a) 

6 962 000 592.7 5.4 32.00 222 762 610 

6 962 000 592.7 6.2 37.00 257 610 706 

Average: 

(Vegter Map & DWAF, SA GW Resources) 

* Note that the recharge volume calculations are a function of the mean annual rainfall of the area, recharge percentage assigned and the surface area of the dyke group 

catchment. Also note that the estimated available recharge to the aquifer is only available for abstraction purposes if sufficient dolerite dykes structures and associated 

fractures are available in geology of the site aquifer. 

Appendix 4 – Groundwater Potential Study for Small Towns June 2012 

658


Table 3.3: Recharge Volume Calculation Scenarios for Dyke Group B 

Dyke Group 

Name 

Dyke Group B 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Table 3.4: Recharge Volume Calculation Scenarios for Dyke Group C 

Table 3.5: Recharge Volume Calculation Scenarios for Dyke Group D 

Estimation of 


(m 3 /a) 

Estimation of 


(m 3 /d) 

2% Recharge 80 950 000 592.7 2.0 12 959 581 2 629 

3% Recharge 80 950 000 592.7 3.0 18 1 439 372 3 943 


(32 mm/a) 



80 950 000 592.7 5.4 32 2 590 150 7 096 

80 950 000 592.7 6.2 37 2 995 333 8 206 

Average: 


Assumptions: 




Dyke Group 

Name 

Dyke Group C 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Estimation of 


(m 3 /a) 


7 651 

Estimation of 


(m 3 /d) 

2% Recharge 7 859 000 592.7 2.0 12 93 161 255 

3% Recharge 7 859 000 592.7 3.0 18 139 741 383 


(32 mm/a) 



7 859 000 592.7 5.4 32 251 464 689 

7 859 000 592.7 6.2 37 290 801 797 

Average: 


Assumptions: 




Dyke Group 

Name 

Dyke Group D 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Estimation of 


(m 3 /a) 

743 

Estimation of 


(m 3 /d) 

2% Recharge 14 490 000 592.7 2.0 12 171 764 471 

3% Recharge 14 490 000 592.7 3.0 18 257 647 706 


(32 mm/a) 



14 490 000 592.7 5.4 32 463 635 1 270 

14 490 000 592.7 6.2 37 536 163 1 469 

Average: 


Assumptions: 




1 370


Figure 3.6: Locality Map of the Delineated Dolerite Dyke Groups near Wepener as utilised for the Groundwater Resource Potential Estimation 



Figure 3.7: Locality Map of the Estimated Mini-Catchments of the Dyke Groups near Wepener 




DYKE STRUCTURES 

The theoretical potential yield or groundwater resource potential estimation of the dolerite dyke structure in 

this section is based on the geometric mean of sustainable yield calculations of borehole fields in the Karoo 

Super Group geology. The aquifer test data for the geometric mean utilised were taken from the borehole 

fields of Petrusburg, Philipstown, Edenville, Colesberg, Igomotseng, Winburg, Brandfort and the Drie 

Susters Area 

The groundwater resource potential is calculated by utilising the above mentioned geometric mean of 60.48 

m 3 /d per borehole or 2.1 L/s per borehole based on an 8-hour pump cycle and 16-hour recovery period per 

day. The lengths of the potential structures were taken into account whereby a borehole was spaced on 

the structure every 250 metres. Therefore the number of the boreholes that can be spaced on the structure 

multiplied by the geometric mean (2.1 L/s over 8-hours a day) is equal to the estimated groundwater 

resource potential of the dolerite dyke structure. 

The assumptions of the method are as follows: 

That potential dolerite dykes are water bearing. 

An average geometric mean sustainable yield of 60.48 m3/d or 2.1 L/s with an 8-hour pump schedule 

and a 16 hour recovery period per borehole (Geometric mean average obtained from borehole fields 

of Petrusburg, Philipstown, Edenville, Colesberg, Igomotseng, Winburg, Brandfort and the Drie 

Susters Area). 

Spacing of the boreholes every 250 m along the strike of the dolerite dyke structure (note that no 

boreholes are placed at the end points of the structures). 

The results of the potential yields of the dolerite dyke groups based on the geometric mean of sustainable 

yield calculations are as follows (refer to Figure 3.6 as well as Table 3.6): 

The groundwater resource potential for Dyke Group A is estimated at 847 m 3 /d. The number of 

dykes of the dolerite group is 3 with a combined length of 5.0 km upon, which 14 potential boreholes 

are spaced for calculation purposes. 

The groundwater resource potential for Dyke Group B is estimated at 12 761 m 3 /d. The number of 

dykes of the dolerite group is 17 with a combined length of 62.60 km upon, which 211 potential 

boreholes are spaced for calculation purposes. 

The groundwater resource potential for Dyke Group C is estimated at 1 210 m 3 /d. The number of 



The groundwater resource potential for Dyke Group D is estimated at 1 331 m 3 /d. The number of 





Table 3.6: Theoretically estimated Dyke Group yields or groundwater resource potential based 

on the geometric mean of sustainable yields of Karoo Borehole Fields, see 

assumption section below the table for further information regarding the 

calculations 

Dyke Group 

Name 

Theoretically Estimated Dyke Group Yields (Geomean) 

Number of 

Dykes 

Total Length 

of Dykes 

(km) 

Number of Potential 

Boreholes 

(250 m Spacing) 

Estimated Yield 

of Dyke Groups 

(m 3 /d) 

A 3 5.00 14 847 

B 17 62.60 211 12 761 

C 4 7.00 20 1 210 

D 5 8.00 22 1 331 

Total 29 82.6 267 16 148 

Assumptions: 

* That potential dolerite dykes are water bearing. 

* An average geomean sustainable yield of 60.48 m 

* Refer to Dyke Group Map for the spatial localities. 

3 /d base on a 2.1 L/s with a 8-hour 

pump schedule and a 14 recovery period per borehole (Geomean average obtained from 

borehole fields of Petrusburg, Philipstown, Edenville, Colesberg, Igomotseng, Winburg, 

Brandfort and the Drie Susters Area). 

* Spacing of the boreholes every 250 m along the strike of the dolerite dyke structure 

(note that no boreholes are placed at the end points of the structures). 

3.7 SUMMARY OF THE RESULTS – GROUNDWATER RESOURCE POTENTIAL 

OF THE INTRUSIVE DOLERITE STRUCTURES 

This section combines the groundwater potential estimation, which includes the recharge based approach 

as the lower boundary and the geometric mean approach as the upper boundary of the estimated 

groundwater potential range. The summary of the estimated groundwater resource potential for the 

delineated dyke groups are as follows (refer to Figure 3.6): 

The groundwater resource potential for Dyke Group A is estimated in the order of between 658 to 

847 m 3 /d. 

The groundwater resource potential for Dyke Group B is estimated in the order of between 7 651 to 

12 761 m 3 /d. 

The groundwater resource potential for Dyke Group C is estimated in the order of between 743 to 

1 210 m 3 /d. 

The groundwater resource potential for Dyke Group D is estimated in the order of between 1 331 to 

1 370 m 3 /d. 

3.7.1 Cost estimate of developing the proposed borehole fields 

The estimated costing for developing the proposed borehole fields only includes the cost for the 

geophysical siting, percussion drilling, aquifer test pumping, pump equipment and pump house structure 

costs of the proposed borehole fields and does not include the cost of the surface infrastructure such as the 

electrical supply lines and pipeline networks and associated reservoirs etc. The estimated costs for 

developing the borehole fields are as follows (refer to Table 3.7): 

The estimated cost for the development of the borehole field for Dyke Group A is R 2 576 000 

The estimated cost for the development of the borehole field for Dyke Group B is R 37 769 000 



The estimated cost for the development of the borehole field for Dyke Group C is R 3 580 000 

The estimated cost for the development of the borehole field for Dyke Group D is R 3 938 000 



Supply Lines and Pipeline Networks etc. 

Dyke Group 

Name 

Number of 

Boreholes to be 

Developed 

Estimated 

Potential Yield 

(m 3 /d) 

Estimation of the Borehole Field Development Cost for the Dyke Groups 

Geophysical & 

Geohydrological 

Activity Costs 

Cost of Percussion 

Drilling of the 

Boreholes 

3.8 DETERMINATION OF HIGH GROUNDWATER ABSTRACTION AREAS 

A high groundwater abstraction area hydrocensus was conducted to determine if groundwater is utilised 

extensively in a 10 -15 km radius around the community of Wepener. The hydrocensus was undertaken by 

means of aerial photographs. Five irrigation pivots were identified to the north east of Wepener (refer to 

Figure 3.8). The coordinates of the irrigation pivots can be viewed in Table 3.8. 

Table 3.8: Coordinates of the Identified Irrigation Pivots 

Aquifer Test 

Pumping Cost of 

Boreholes 

Pumping 

Equ i pm e n t C ost 

Pump House 

Structure Cost 

It is important to note that the irrigation pivots are situated next to the Caledon River (refer to Figure 3.8). 

Therefore it is more likely that these irrigation pivots utilised surface water than groundwater. It is 

recommended that these areas be investigated to confirm the observation. Groundwater is also utilised by 

many farmers for domestic purposes at their farmsteads. Groundwater uses may include, drinking water 

purposes, washing of clothes and food preparation as well as watering of the farmstead gardens. 


Total C ost of 

Borehole Field 

(Excl. Vat) 

Dyke Group A 14 658 - 847 R 308 000.00 R 700 000.00 R 308 000.00 R 350 000.00 R 910 000.00 R 2 576 000.00 

Dyke Group B 211 7 651 - 12 761 R 4 642 000.00 R 10 550 000.00 R 4 642 000.00 R 4 220 000.00 R 13 715 000.00 R 37 769 000.00 

Dyke Group C 20 743 - 1 210 R 440 000.00 R 1 000 000.00 R 440 000.00 R 400 000.00 R 1 300 000.00 R 3 580 000.00 

Dyke Group D 22 1 331 - 1 370 R 484 000.00 R 1 100 000.00 R 484 000.00 R 440 000.00 R 1 430 000.00 R 3 938 000.00 

Total Cost R 47 863 000.00 

* Note that the above costing only includes the geophysical siting, percussion drilling, aquifer test pumping, pump equipment and pump house structure costs of the proposed 

borehole fields and do not include the cost of the surface infrastructure such as the electrical supply lines and pipeline networks etc. 

Coordinates (WGS84) 

Pivot Site Name 

Eas t S ou th 

Pivot A 27.04588 -29.62038 

Pivot B 27.05359 -29.61798 

Pivot C 27.05518 -29.62396 

Pivot D 27.04953 -29.62707 

Pivot E 27.05570 -29.63004


Figure 3.8: Locality Map of the Potential High Groundwater Abstraction Areas in the vicinity of Wepener. Note that the Irrigation Pivots are situated next to the Caledon River. Therefore it is more likely that these pivots 

utilised Surface Water than Groundwater. It is recommended that these areas be investigated to confirm the observation 



3.9 CONCLUSIONS AND RECOMMENDATIONS 

The following conclusions and recommendations are based on the information supplied in this report: 

CATCHMENT 

The study area is located in north eastern part of the Free State Province in Water Management Area 13. 

The study area is also located in Drainage Area D, Quaternary sub-catchment D23G and D23J (Surface 

Water Resources of South Africa, First Edition, 1994). 

CLIMATE 


temperatures range from an average maximum of 30 to 32 o C in January to an average minimum of 0 to 2 o C 

in July, meaning conditions with hot summers and cold winters (South African Atlas of Agrohydrology and – 

Climatology, 1997). 

Wepener has no rainfall station, therefore the rainfall for Dewetsdorp is assumed for Wepener. Dewetsdorp 

is located approximately 35 km away from Wepener in a north westerly direction. The mean annual rainfall 

is 592.7 mm/a, which occurs mainly as thunderstorms but soft rains also do occur (Rainfall Station Gauge 

No.: 0232 275, Dewetsdorp Police Station, Surface Water Resources of South Africa, 1990). 

GEOLOGY 

The geology of the Wepener district consists of the Karoo Super Group geology and more specifically of the 

Beaufort Group Upper Stage, which comprises of sedimentary rocks such as purple and green shale and 

mudstone 

The whole sedimentary sequence has been intruded by dolerite dyke and sill structures. The dolerite dykes 

are the primary targets for groundwater resource development. 

GENERAL AQUIFER INFORMATION OF THE WEPENER DISTRICT 


The groundwater component of river flow (base flow) is 0 – 10 mm/a in the Wepener district. The 

groundwater depth in the study area is approximately 10 – 20 mbgl (standard deviation range from mean is 

between 8 – 15 m). The mean annual recharge of the area are between 25 - 37 mm/a. 





is 0.001 to 0.01. 

GROUNDWATER POTENTIAL INVESTIGATION 




Aerial Photo Interpretation 

The aerial photo interpretation of the Wepener study area revealed 31 potential dolerite dyke structures that 

can be verified by means of geophysical methods and percussion drilling. The dolerite dyke structures are 

considered the primary targets for groundwater exploration in the Karoo Supergroup geology. 



Aerial Magnetic Data Interpretation 

The aerial magnetic map revealed numerous dolerite sill intrusions in the study area. The study area is 

located on the sedimentary rocks of the Beaufort Group of the Karoo Supergroup. The green and blue 

areas on the aerial magnetic contour map denote sedimentary rocks. Dolerite intrusives such as dykes and 

sill structures are denoted as the red and yellow areas of the aerial magnetics map. 





Geological Map Interpretation 

The geological map interpretation of the Wepener study area revealed 31 potential dolerite dyke structures, 

which confirms the aerial photo interpretations, which also indicated the potential presence of these dolerite 

structures. 

RECHARGE WATER BUDGET CALCULATIONS AND ESTIMATED THEORETICAL YIELDS OF 

POTENTIAL DOLERITE DYKE STRUCTURES 





geology. 







Recharge Water Budget Calculations 




Recharge Map (1995). 


of the dyke groups. The aim of the recharge volume calculations is to estimate the available 

recharge volume available to the dyke groups in the study area. The assumption thus made is that the 

available recharge volume correlates roughly to the sustainable yield available from the dolerite dyke 

groups. This method is only a rough approximation of potential sustainable yields due to that the 

sustainability of the intrusive structure is a function of the capture zone, which in turn entails the dynamics 

of the aquifer system (The Water budget Myth Revisited; Why Hydrogeologist Model, Bredehoeft, 2002). 

The main to tool for investigating the capture zone and aquifer dynamics is the numerical groundwater 

model. Unfortunately not enough geohydrological information exists in terms of aquifer parameters to 

construct such a model. Therefore only rough estimation can be made regarding the groundwater resource 

potential. 




follows: 

Estimated groundwater resource potential is estimated for Dyke Group A as approximately 658 m 3 /d. 


m 3 /d. 

Estimated groundwater resource potential is estimated for Dyke Groups C as approximately 

743 m 3 /d. 

Estimated groundwater resource potential is estimated for Dyke Group D as approximately 1 370 

m 3 /d. 

The estimated high growth scenario for the average annual daily water demand for Wepener was obtained 

from Aurecon and is 2 871 m 3 /d or kl/d. The estimated recharge area needed to address the above 

demand is approximately 30.4 km 2 . 

Estimation of Theoretical Potential Yield of the Dolerite Dyke Structures 





Susters Area 



day. The length of the potential structures were taken into account whereby a borehole was spaced on the 

structure every 250 metres. Therefore the number of the boreholes that can be spaced on the structure 





An average geometric mean sustainable yield of 60.48 m 3 /d or 2.1 L/s with an 8-hour pump schedule 

and a 14 recovery period per borehole (Geometric mean average obtained from borehole fields of 

Petrusburg, Philipstown, Edenville, Colesberg, Igomotseng, Winburg, Brandfort and the Drie Susters 

Area). 




yield calculations are as follows: 

The groundwater resource potential for Dyke Group A is estimated at 847 m 3 /d. The number of 











The groundwater resource potential for Dyke Group D is estimated at 1 331 m 3 /d. The number of 



Summary of the Results Groundwater Resource Potential of the Intrusive Dolerite Structures 




delineated dyke groups are as follows: 


847 m 3 /d. 


12 761 m 3 /d. 

The groundwater resource potential for Dyke Group C is estimated in the order of between 743 to 

1 210 m 3 /d. 

The groundwater resource potential for Dyke Group D is estimated in the order of between 1 331 to 

1 370 m 3 /d. 



costs of the proposed borehole fields and do not include the cost of the surface infrastructure such as the 

electrical supply lines and pipeline networks and associated reservoirs etc. 

The estimated costing for developing the borehole fields are as follows: 





DETERMINATION OF HIGH GROUNDWATER ABSTRACTION AREAS 


extensively in a 10 -15 km radius around the community of Wepener. The hydrocensus was undertaken by 

means of aerial photographs. Five irrigation pivots were identified to the north east of Wepener. 

It is important to note that the irrigation pivots are situated next to the Caledon River. Therefore it is more 

likely that these irrigation pivots utilised surface water than groundwater. It is recommended that these 

areas be investigated to confirm the observation. Groundwater is also utilised by many farmers for 

domestic purposes at their farmsteads. Groundwater uses may include, drinking water purposes, washing 

of clothes and food preparation as well as watering of the farmstead gardens. 

FINAL CONCLUSIONS AND RECOMMENDATIONS 

It is concluded that 31 potential dolerite dykes was observed that can be further investigated. Information 

absent regarding the observed dolerite structures are that it is currently unknown if these structures are 

water bearing. If so what the true sustainable yields are of these structures, not the estimate yields, as well 

as the associated groundwater qualities. 

The desktop study indicate that it is viable to further investigate the groundwater resources of Wepener 

based on the numerous potential dolerite dykes observed in the vicinity of Wepener. It is recommended 

that any future orientated groundwater exploration study at least include the following components: 








aquifer; 

Aquifer test pumping analyses of data to calculate sustainable yields and pump schedules. 




4. DEWETSDORP 


The study area is also located in Drainage Area C and D, Quaternary sub-catchment C52A and D23H 

(Surface Water Resources of South Africa, First Edition, 1994). The locality map of the Dewetsdorp study 

area can be viewed in Figure 4.1. 

4.1 CLIMATE 





The mean annual rainfall is 592.7 mm/a, which occurs mainly as thunderstorms but soft rains also do occur 

(Rainfall Station Gauge No.: 0232 275, Dewetsdorp Police Station, Surface Water Resources of South 

Africa, 1990). 

4.2 GEOLOGY 

4.2.1 General aquifer information of the Dewetsdorp District 


The groundwater component of river flow (base flow) is negligible in the Dewetsdorp district (refer to Figure 



15 - 25 mm/a (refer to Figure 2.3). 





is 0.001 to 0.01. 



Figure 4.1: Locality Map of the Dewetsdorp Study Area 



Figure 4.2: Geological Map of the Dewetsdorp Study Area 



Figure 4.3: Locality Map of the Aerial Photo Interpretations of the Dewetsdorp Study Area 



4.3 GROUNDWATER POTENTIAL INVESTIGATIONS 





The aerial photo interpretation of the Dewetsdorp study area revealed 26 potential dolerite dyke structures 

that can be verified by means of geophysical methods and percussion drilling. The dolerite dyke structures 

are considered the primary targets for groundwater exploration in the Karoo Supergroup geology. The 

aerial photo map of the study area can be viewed in Figure 4.3. 

4.3.2 Results of the aerial magnetic data interpretation 



green and blue areas on the aerial magnetic contour map denote sedimentary rocks. Dolerite intrusives 

such as dykes and sill structures are denoted as the red and yellow areas of the aerial magnetics map. 






The geological map interpretation of the Dewetsdorp study area revealed 26 potential dolerite dyke 

structures, which confirms the aerial photo interpretations, which also indicated the potential presence of 

these dolerite structures. The aerial photo map of the study area can be viewed in Figure 4.5. 



Figure 4.4: Aerial Magnetic Data Contour Map for the Dewetsdorp Area. Note that the red and yellow areas denote areas of Higher Magnetic Intensity that are associated with Dolerite Sill Intrusions. The green and blue 

areas refer to Sedimentary Rocks of the Beaufort Group (Karoo Supergroup) 




THEORETICAL YIELDS OF POTENTIAL DOLERITE STRUCTURES 





geology. 













of the dyke groups as delineated in Figure 4.5 and Figure 4.6. The aim of the recharge volume 

calculations is to estimate the available recharge volume available to the dyke groups in the study area. 

The assumption thus made is that the available recharge volume correlates roughly to the sustainable yield 

available from the dolerite dyke groups. This method is only a rough approximation of potential sustainable 

yields because the sustainability of the intrusive structure is a function of the capture zone, which in turn 

entails the dynamics of the aquifer system (The Water budget Myth Revisited; Why Hydrogeologist Model, 

Bredehoeft, 2002). The main to tool for investigating the capture zone and aquifer dynamics is the 

numerical groundwater model. Unfortunately not enough geohydrological information exists in terms of 

aquifer parameters to construct such a model. Therefore only rough estimation can be made regarding the 

groundwater resource potential. 



Estimated groundwater resource potential is estimated for Dyke Group A as approximately 1 845 




Estimated groundwater resource potential is estimated for Dyke Groups C as approximately 1 057 


Estimated groundwater resource potential is estimated for Dyke Group D as approximately 647 m 3 /d 


Estimated groundwater resource potential is estimated for Dyke Group E as approximately 1 072 


Estimated groundwater resource potential is estimated for Dyke Group F as approximately 2 469 




The estimated high growth scenario for the average annual daily water demand for Dewetsdorp was 

obtained from Aurecon and is 3 203 m 3 /d or kl/d. The estimated recharge area needed to address the 

above demand is approximately 52.0 km 2 . 


thus made is that the Available Recharge Volume correlates roughly to the 

Sustainable Yield available from the Dolerite Dyke Groups 




(m 3 /a) 


(m 3 /d) 

Dyke Group A 673 344 1 845 

Dyke Group B 938 226 2 570 

Dyke Group C 385 733 1 057 

Dyke Group D 236 076 647 

Dyke Group E 391 134 1 072 

Dyke Group F 901 318 2 469 

Total 3 525 830 9 660 

Assumptions: 








Dyke Group 

Name 

Dyke Group A 

Assumptions: 


Es ti m ati on of Dyk e 


(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Esti m ati on of 


(m 3 /a) 

Es ti m ati on of 


(m 3 /d) 

2% Recharge 29 920 000 592.7 2.0 12 354 672 972 

3% Recharge 29 920 000 592.7 3.0 18 532 008 1 458 


(20 mm/a) 



29 920 000 592.7 3.4 20.00 598 331 1 639 

29 920 000 592.7 4.2 25.01 748 357 2 050 

Average: 






1 845



Dyke Group 

Name 

Dyke Group B 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Table 4.4. Recharge Volume Calculation Scenarios for Dyke Group C 




(m 3 /a) 



(m 3 /d) 

2% Recharge 41 690 000 592.7 2.0 12 494 193 1 354 

3% Recharge 41 690 000 592.7 3.0 18 741 290 2 031 


(20 mm/a) 



41 690 000 592.7 3.4 20 833 704 2 284 

41 690 000 592.7 4.2 25 1 042 748 2 857 

Average: 


Assumptions: 




Dyke Group 

Name 

Dyke Group C 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 



(m 3 /a) 


2 570 



(m 3 /d) 

2% Recharge 17 140 000 592.7 2.0 12 203 178 557 

3% Recharge 17 140 000 592.7 3.0 18 304 766 835 


(20 mm/a) 



17 140 000 592.7 3.4 20 342 761 939 

17 140 000 592.7 4.2 25 428 705 1 175 

Average: 


Assumptions: 




Dyke Group 

Name 

Dyke Group D 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 



(m 3 /a) 

1 057 



(m 3 /d) 

2% Recharge 10 490 000 592.7 2.0 12 124 348 341 

3% Recharge 10 490 000 592.7 3.0 18 186 523 511 


(20 mm/a) 



10 490 000 592.7 3.4 20 209 776 575 

10 490 000 592.7 4.2 25 262 375 719 

Average: 


Assumptions: 




647


Table 4.6: Recharge Volume Calculation Scenarios for Dyke Group E 

Dyke Group 

Name 

Dyke Group E 

Assumptions: 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Table 4.7: Recharge Volume Calculation Scenarios for Dyke Group F 



(m 3 /a) 



(m 3 /d) 

2% Recharge 17 380 000 592.7 2.0 12 206 023 564 

3% Recharge 17 380 000 592.7 3.0 18 309 034 847 


(20 mm/a) 



17 380 000 592.7 3.4 20 347 560 952 

17 380 000 592.7 4.2 25 434 708 1 191 

Average: 





Dyke Group 

Name 

Dyke Group F 

Assumptions: 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 



(m 3 /a) 


1 072 



(m 3 /d) 

2% Recharge 40 050 000 592.7 2.0 12 474 753 1 301 

3% Recharge 40 050 000 592.7 3.0 18 712 129 1 951 


(20 mm/a) 



40 050 000 592.7 3.4 20 800 908 2 194 

40 050 000 592.7 4.2 25 1 001 728 2 744 

Average: 





2 469


Figure 4.5: Locality Map of the Delineated Dolerite Dyke Groups near Dewetsdorp as utilised for the Groundwater Resource Potential Estimation 



Figure 4.6: Locality Map of the Estimated Mini-Catchments of the Dyke Groups near Dewetsdorp 









Susters Area 










and a 16 hour recovery period per borehole (Geometric mean average obtained from borehole fields 

of Petrusburg, Philipstown, Edenville, Colesberg, Igomotseng, Winburg, Brandfort and the Drie 

Susters Area). 





The groundwater resource potential for Dyke Group A is estimated at 5 867 m 3 /d. The number of 









The groundwater resource potential for Dyke Group D is estimated at 786 m 3 /d. The number of 



The groundwater resource potential for Dyke Group E is estimated at 1 452 m 3 /d. The number of 



The groundwater resource potential for Dyke Group F is estimated at 4 657 m 3 /d. The number of 








calculations 

Dyke Group 

Name 


Number of 

Dykes 

Total Length 

of Dykes 

(km) 


Boreholes 




(m 3 /d) 

A 8 27.45 97 5 867 

B 4 27.80 102 6 169 

C 3 10.60 36 2 177 

D 5 5.30 13 786 

E 3 8.00 24 1 452 

F 7 22.90 77 4 657 

Total 30 102.05 349 21 108 

Assumptions: 
















The groundwater resource potential for Dyke Group A is estimated in the order of between 1 845 to 

5 867 m 3 /d. 


6 169 m 3 /d. 

The groundwater resource potential for Dyke Group C is estimated in the order of between 1 057 to 

2 177 m 3 /d. 

The groundwater resource potential for Dyke Group D is estimated in the order of between 647 to 

786 m 3 /d. 

The groundwater resource potential for Dyke Group E is estimated in the order of between 1 072 to 

1 452 m 3 /d. 

The groundwater resource potential for Dyke Group F is estimated in the order of between 2 469 to 

4 657 m 3 /d. 








The estimated costing for developing the borehole fields are as follows (refer to Table 4.9): 

The estimated cost for the development of the borehole field for Dyke Group A is R 17 848 000. 

The estimated cost for the development of the borehole field for Dyke Group B is R 18 258 000. 

The estimated cost for the development of the borehole field for Dyke Group C is R 6 444 000. 

The estimated cost for the development of the borehole field for Dyke Group D is R 2 327 000. 

The estimated cost for the development of the borehole field for Dyke Group E is R 4 296 000. 

The estimated cost for the development of the borehole field for Dyke Group F is R 13 783 000. 



Supply Lines and Pipeline Networks etc 

Dyke Group 

Name 

Number of 


Developed 

Estimated 

Potential 

Yield 

(m 3 /d) 


Geophysical & 





Boreholes 

Aquifer Test 


Boreholes 

Pumping 


Pump House 



Total C os t of 


(Excl. Vat) 

Dyke Group A 97 1 845 - 5 867 R 2 134 000.00 R 4 850 000.00 R 2 134 000.00 R 2 425 000.00 R 6 305 000.00 R 17 848 000.00 

Dyke Group B 102 2 570 - 6 169 R 2 244 000.00 R 5 100 000.00 R 2 244 000.00 R 2 040 000.00 R 6 630 000.00 R 18 258 000.00 

Dyke Group C 36 1 057 - 2 177 R 792 000.00 R 1 800 000.00 R 792 000.00 R 720 000.00 R 2 340 000.00 R 6 444 000.00 

Dyke Group D 13 647 - 786 R 286 000.00 R 650 000.00 R 286 000.00 R 260 000.00 R 845 000.00 R 2 327 000.00 

Dyke Group E 24 1 072 - 1 452 R 528 000.00 R 1 200 000.00 R 528 000.00 R 480 000.00 R 1 560 000.00 R 4 296 000.00 

Dyke Group F 77 2 469 - 4 657 R 1 694 000.00 R 3 850 000.00 R 1 694 000.00 R 1 540 000.00 R 5 005 000.00 R 13 783 000.00 

Total Cost R 62 956 000.00 




extensively in a 10 -15 km radius around the community of Dewetsdorp. The hydrocensus was undertaken 

by means of aerial photographs. Ten irrigation pivots were identified to the west of Dewetsdorp (refer to 

Figure 4.7). The coordinates of the irrigation pivots can be viewed in Table 4.10. 






Eas t S ou th 

Pivot A 26.54402 -29.48199 

Pivot B 26.54858 -29.48227 

Pivot C 26.55435 -29.48978 

Pivot D 26.54140 -29.49546 

Pivot E 26.55916 -29.49497 

Pivot F 26.56265 -29.50297 

Pivot G 26.55991 -29.50591 

Pivot H 26.58353 -29.55913 

Pivot I 26.58354 -29.56270 

Pivot J 26.52174 -29.64466 

It is important to note that the irrigation pivots are situated next to non-perennial streams and dams (refer to 

Figure 4.7). Therefore it is more likely that these irrigation pivots utilised surface water than groundwater. 

It is recommended that these areas be investigated to confirm the observation. Groundwater is also utilised 

by many farmers for domestic purposes at their farmsteads. Groundwater uses may include, drinking water 




Figure 4.7: Locality Map of the Potential High Groundwater Abstraction Areas in the vicinity of Dewetsdorp. Note that the Irrigation Pivots are situated next to Non-Perennial Streams and Small Dams. Therefore it is more 

likely that these Pivots utilised Surface Water than Groundwater. It is recommended that these areas be investigated to confirm the observation 





CATCHMENT 


The study area is also located in Drainage Area C and D, Quaternary sub-catchment C52A and D23H 

(Surface Water Resources of South Africa, First Edition, 1994). 

CLIMATE 






(Rainfall Station Gauge No.: 0232 275, Dewetsdorp Police Station, Surface Water Resources of South 


GEOLOGY 

The geology of the Dewetsdorp district consists of the Karoo Super Group geology and more specifically of 

the Beaufort Group Upper Stage, which comprises of sedimentary rocks such as purple and green shale 

and mudstone. 



GENERAL AQUIFER INFORMATION OF THE DEWETSDORP DISTRICT 


The groundwater component of river flow (base flow) is negligible in the Dewetsdorp district. The 







is 0.001 to 0.01. 






The aerial photo interpretation of the Dewetsdorp study area revealed 26 potential dolerite dyke structures 


are considered the primary targets for groundwater exploration in the Karoo Supergroup geology. 



located on the sedimentary rocks of the Beaufort Group of the Karoo Supergroup. The green and blue 



areas on the aerial magnetic contour map denote sedimentary rocks. Dolerite intrusives such as dykes and 

sill structures are denoted as the red and yellow areas of the aerial magnetics map. 






The geological map interpretation of the Dewetsdorp study area revealed 26 potential dolerite dyke 


these dolerite structures. 







geology. 






















potential. 


follows: 

Estimated groundwater resource potential is estimated for Dyke Group A as approximately 

1 845 m 3 /d. 

Estimated groundwater resource potential is estimated for Dyke Group B as approximately 

2 570 m 3 /d. 




m 3 /d. 

Estimated groundwater resource potential is estimated for Dyke Group D as approximately 647 m 3 /d. 


m 3 /d. 

Estimated groundwater resource potential is estimated for Dyke Group F as approximately 2 469 

m 3 /d. 

The estimated high growth scenario for the average annual daily water demand for Dewetsdorp was 








Susters Area 












Area). 






























The groundwater resource potential for Dyke Group A is estimated in the order of between 1 845 to 

5 867 m 3 /d. 


6 169 m 3 /d. 


2 177 m 3 /d. 


786 m 3 /d. 


1 452 m 3 /d. 

The groundwater resource potential for Dyke Group F is estimated in the order of between 2 469 to 

4 657 m 3 /d. 










The estimated cost for the development of the borehole field for Dyke Group E is R 4 296 000 

The estimated cost for the development of the borehole field for Dyke Group F is R 13 783 000 



extensively in a 10 -15 km radius around the community of Dewetsdorp. The hydrocensus was undertaken 

by means of aerial photographs. Ten irrigation pivots were identified to the west of Dewetsdorp. 

It is important to note that the irrigation pivots are situated next to non-perennial streams and dams. 

Therefore it is more likely that these irrigation pivots utilised surface water than groundwater. It is 











The desktop study indicate that it is viable to further investigate the groundwater resources of Dewetsdorp 

based on the numerous potential dolerite dykes observed in the vicinity of Dewetsdorp. It is recommended 







aquifer; 





5. REDDERSBURG 


The study area is also located in Drainage Area C, Quaternary sub-catchment C51A and to a lesser extent 

in C51B (Surface Water Resources of South Africa, First Edition, 1994). 

5.1 CLIMATE 






(Rainfall Station Gauge No.: 0231 279, Reddersburg Police Station, Surface Water Resources of South 


5.2 GEOLOGY 

5.2.1 General aquifer information for Reddersburg 


The groundwater component of river flow (base flow) is negligible in the Reddersburg district (refer to 

Figure 2.3). The groundwater depth in the study area is approximately 10 – 20 mbgl (standard deviation 

range from mean is between 8 – 15 m), refer to Figure 2.4. The mean annual recharge of the area are 

between 15 - 25 mm/a (refer to Figure 2.5). 





is 0.001 to 0.01. 



Figure 5.1: Locality Map of the Reddersburg Study Area 



Figure 5.2: Geological Map of the Reddersburg Study Area 








The aerial photo interpretation of the Reddersburg study area revealed 52 potential dolerite dyke structures 




5.3.2 Results of the aerial data interpretation 



green and blue area on the aerial magnetic contour map denotes sedimentary rocks. Dolerite intrusives 

such as dykes and sill structures are denoted as the red and pinkish / purple areas of the aerial magnetics 

map. 






The geological map interpretation of the Reddersburg study area revealed 52 potential dolerite dyke 





Figure 5.3: Locality Map of the Aerial Photo Interpretations of the Reddersburg Study Area 



Figure 5.4: Aerial Magnetic Data Contour Map for the Reddersburg Area. Note that the red and pinkish / purple areas denote areas of Higher Magnetic Intensity that are associated with Dolerite Sill Intrusions. The green 

and blue areas refer to Sedimentary Rocks of the Beaufort Group (Karoo Supergroup) 



Figure 5.5: Geological Map of the Reddersburg Study Area. The Geological Map confirms the presence of at least 52 Potential Dolerite Dykes as determined by the Aerial Photo Interpretations 




THEORETICAL YIELDS OF POTENTIAL DOLERITE STRUCTURES 





geology. 



















Hydrogeologist Model, Bredehoeft, 2002). The main to tool for investigating the capture zone and aquifer 
















Estimated groundwater resource potential is estimated for Dyke Group F as approximately 597 m 3 /d 




The estimated high growth scenario for the average annual daily water demand for Reddersburg was 





Sustainable Yield Available from the Dolerite Dyke Groups 




(m 3 /a) 


(m 3 /d) 


Dyke Group B 441 914 1 211 

Dyke Group C 706 748 1 936 


Dyke Group E 881 128 2 414 

Dyke Group F 218 032 597 

Total 2 829 466 7 752 

Assumptions: 








Dyke Group 

Name 

Dyke Group A 

Assumptions: 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Estimation of 


(m 3 /a) 

Estimation of 


(m 3 /d) 

2% Recharge 15 670 000 490.8 2.0 10 153 817 421 

3% Recharge 15 670 000 490.8 3.0 15 230 725 632 


(20 mm/a) 



15 670 000 490.8 4.1 20 313 325 858 

15 670 000 490.8 5.1 25 391 848 1 074 

Average: 






966



Dyke Group 

Name 

Dyke Group B 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Table 5.4: Recharge Volume Calculation Scenarios for Dyke Group C 


Estimation of 


(m 3 /a) 

Estimation of 


(m 3 /d) 

2% Recharge 19 640 000 490.8 2.0 10 192 786 528 

3% Recharge 19 640 000 490.8 3.0 15 289 179 792 


(20 mm/a) 



19 640 000 490.8 4.1 20 392 706 1 076 

19 640 000 490.8 5.1 25 491 123 1 346 

Average: 


Assumptions: 




Dyke Group 

Name 

Dyke Group C 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Estimation of 


(m 3 /a) 


1 211 

Estimation of 


(m 3 /d) 

2% Recharge 31 410 000 490.8 2.0 10 308 321 845 

3% Recharge 31 410 000 490.8 3.0 15 462 481 1 267 


(20 mm/a) 



31 410 000 490.8 4.1 20 628 049 1 721 

31 410 000 490.8 5.1 25 785 447 2 152 

Average: 


Assumptions: 




Dyke Group 

Name 

Dyke Group D 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Estimation of 


(m 3 /a) 

1 936 

Estimation of 


(m 3 /d) 

2% Recharge 10 180 000 490.8 2.0 10 99 927 274 

3% Recharge 10 180 000 490.8 3.0 15 149 890 411 


(20 mm/a) 



10 180 000 490.8 4.1 20 203 551 558 

10 180 000 490.8 5.1 25 254 564 697 

Average: 


Assumptions: 




628



Dyke Group 

Name 

Dyke Group E 

Assumptions: 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 


Estimation of 


(m 3 /a) 

Estimation of 


(m 3 /d) 

2% Recharge 39 160 000 490.8 2.0 10 384 395 1 053 

3% Recharge 39 160 000 490.8 3.0 15 576 592 1 580 


(20 mm/a) 



39 160 000 490.8 4.1 20 783 012 2 145 

39 160 000 490.8 5.1 25 979 245 2 683 

Average: 





Dyke Group 

Name 

Dyke Group F 

Assumptions: 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Estimation of 


(m 3 /a) 


2 414 

Estimation of 


(m 3 /d) 

2% Recharge 9 690 000 490.8 2.0 10 95 117 261 

3% Recharge 9 690 000 490.8 3.0 15 142 676 391 


(20 mm/a) 



9 690 000 490.8 4.1 20 193 753 531 

9 690 000 490.8 5.1 25 242 311 664 

Average: 





597


Figure 5.6: Locality Map of the Delineated Dolerite Dyke Groups near Reddersburg as utilised for the Groundwater Resource Potential Estimation 



Figure 5.7: Locality Map of the estimated Mini-Catchments of the Dyke Groups near Reddersburg 




STRUCTURES 





Susters Area. 












Area). 




























calculations 

Dyke Group 

Name 


Number of 

Dykes 

Total Length 

of Dykes 

(km) 


Boreholes 




(m 3 /d) 

A 2 9.17 27 1 633 

B 3 10.78 25 1 512 

C 3 23.90 77 4 657 

D 6 6.44 16 968 

E 4 20.00 60 3 629 

F 2 8.91 20 1 210 

Total 20 79.204 225 13 608 

Assumptions: 

















1 633 m 3 /d. 


1 512 m 3 /d. 


4 657 m 3 /d. 


968 m 3 /d. 


3 629 m 3 /d. 

The groundwater resource potential for Dyke Group F is estimated in the order of between 597 to 

1 210 m 3 /d. 
















the Costing does not make provision for Surface Infrastructure such as Electrical 


Dyke Group 

Name 

Number of 


Developed 

Es ti m ate d 

Potential 

Yield 

(m 3 /d) 


Geophysical & 





Boreholes 

Aquifer Test 


Boreholes 

Pumping 

Equ i pm e n t C os t 

Pump House 



Total C os t of 


(Excl. Vat) 

Dyke Group A 27 966 - 1 633 R 594 000.00 R 1 350 000.00 R 594 000.00 R 675 000.00 R 1 755 000.00 R 4 968 000.00 

Dyke Group B 25 1 211 - 1 512 R 550 000.00 R 1 250 000.00 R 550 000.00 R 500 000.00 R 1 625 000.00 R 4 475 000.00 

Dyke Group C 77 1 936 - 4 657 R 1 694 000.00 R 3 850 000.00 R 1 694 000.00 R 1 540 000.00 R 5 005 000.00 R 13 783 000.00 

Dyke Group D 16 628 - 968 R 352 000.00 R 800 000.00 R 352 000.00 R 320 000.00 R 1 040 000.00 R 2 864 000.00 

Dyke Group E 60 2 414 - 3 629 R 1 320 000.00 R 3 000 000.00 R 1 320 000.00 R 1 200 000.00 R 3 900 000.00 R 10 740 000.00 

Dyke Group F 20 597 - 1 210 R 440 000.00 R 1 000 000.00 R 440 000.00 R 400 000.00 R 1 300 000.00 R 3 580 000.00 

Total Cost R 40 410 000.00 




extensively in a 10 -15 km radius around the community of Reddersburg. The hydrocensus was 

undertaken by means of aerial photographs. Nine irrigation pivots were identified to the east of 

Reddersburg (refer to Figure 5.8). The coordinates of the irrigation pivots can be viewed in Table 5.10. 






Eas t S ou th 

Pivot A 26.23138 -29.65522 

Pivot B 26.23431 -29.65539 

Pivot C 26.23269 -29.65776 

Pivot D 26.23411 -29.66012 

Pivot E 26.23664 -29.66160 

Pivot F 26.23755 -29.66327 

Pivot G 26.30232 -29.67022 

Pivot H 26.31555 -29.63979 

Pivot I 26.29655 -29.58655 

It is important to note that the irrigation pivots are situated next to the Riet River and other non-perennial 

streams (refer to Figure 5.8). Therefore it is more likely that these irrigation pivots utilised surface water 

than groundwater. It is recommended that these areas be investigated to confirm the observation. 

Groundwater is also utilised by many farmers for domestic purposes at their farmsteads. Groundwater 

uses may include, drinking water purposes, washing of clothes and food preparation as well as watering of 

the farmstead gardens. 



Figure 5.8: Locality Map of the Potential High Groundwater Abstraction Areas in the vicinity of Reddersburg. Note that the Irrigation Pivots are situated next to the Riet River and other Non-Perennial Streams. Therefore it 

is more likely that these Pivots utilised Surface Water than Groundwater. It is recommended that these areas be investigated to confirm the observation 





CATCHMENT 


The study area is also located in Drainage Area C, Quaternary sub-catchment C51A and to a lesser extent 

in C51B. 

CLIMATE 






(Rainfall Station Gauge No.: 0231 279, Reddersburg Police Station, Surface Water Resources of South 


GEOLOGY 

The geology of the Reddersburg district consists of the Karoo Super Group geology and more specifically 

of the Beaufort Group. 



GENERAL AQUIFER INFORMATION OF THE REDDERSBURG DISTRICT 


The groundwater component of river flow (base flow) is negligible in the Reddersburg district. The 







is 0.001 to 0.01. 






The aerial photo interpretation of the Reddersburg study area revealed 52 potential dolerite dyke structures 





located on the sedimentary rocks of the Beaufort Group of the Karoo Supergroup. The green and blue area 



on the aerial magnetic contour map denotes sedimentary rocks. Dolerite intrusives such as dykes and sill 

structures are denoted as the red and pinkish / purple areas of the aerial magnetics map. 






The geological map interpretation of the Reddersburg study area revealed 52 potential dolerite dyke 









geology. 






















potential. 


follows: 



m 3 /d. 


m 3 /d. 





m 3 /d. 

Estimated groundwater resource potential is estimated for Dyke Group F as approximately 597 m 3 /d. 

The estimated high growth scenario for the average annual daily water demand for Reddersburg was 








Susters Area 












Area). 































1 633 m 3 /d. 


1 512 m 3 /d. 


4 657 m 3 /d. 


968 m 3 /d. 


3 629 m 3 /d. 


1 210 m 3 /d. 













A high groundwater abstraction area hydrocensus was conducted by GHT Consulting to determine if 

groundwater is utilised extensively in a 10 -15 km radius around the community of Reddersburg. The 

hydrocensus was undertaken by means of aerial photographs. Nine irrigation pivots were identified to the 

east of Reddersburg. 


streams. Therefore it is more likely that these irrigation pivots utilised surface water than groundwater. It is 











The desktop study indicate that it is viable to further investigate the groundwater resources of Reddersburg 

based on the numerous potential dolerite dykes observed in the vicinity of Reddersburg. It is 

recommended that any future orientated groundwater exploration study at least include the following 

components: 






aquifer; 





6. EDENBURG 

6.1 CLIMATE 






(Rainfall Station Gauge No.: 0230 764, Edenburg Police Station, Surface Water Resources of South Africa, 

1990). 

6.2 GEOLOGY 

6.2.1 General aquifer information of the Edenburg District 


The groundwater component of river flow (base flow) is negligible in the Edenburg district (refer to Figure 



15 - 25 mm/a (refer to Figure 2.3). 





is 0.001 to 0.01. 



Figure 6.1: Locality Map of the Edenburg Study Area 



Figure 6.2: Geological Map of the Edenburg Study Area 





The aerial photo interpretation of the Edenburg study area revealed 36 potential dolerite dyke structures 




6.3.2 Results of the aerial data interpretation 


The study area is located on the sedimentary rocks of the Adelaide Subgroup (Beaufort Group) of the 

Karoo Supergroup. The green and blue area on the aerial magnetic contour map denotes sedimentary 

rocks. Dolerite intrusives such as dykes and sill structures are denoted as the yellow, red and pinkish / 

purple areas of the aerial magnetics map. 






The geological map interpretation of the Edenburg study area revealed 36 potential dolerite dyke 





Figure 6.3: Locality Map of the Aerial Photo Interpretations of the Edenburg Study Area 



Figure 6.4: Aerial Magnetic Data Contour Map for the Edenburg Area. Note that the yellow, red and pinkish / purple areas denote areas of higher magnetic intensity that are associated with Dolerite Sill Intrusions. The light 

green and blue areas refer to sedimentary rocks of the Adelaide Subgroup of the Beaufort Group (Karoo Supergroup) 



Figure 6.5: Geological Map of the Edenburg Study Area. The Geological Map confirms the Presence of at least 36 Potential Dolerite Dykes as determined by the Aerial Photo Interpretations 




THEORETICAL YIELD OF POTENTIAL DOLERITE DYKE STRUCTURES 





geology. 



















Hydrogeologist Model, Bredehoeft, 2002). The main to tool for investigating the capture zone and aquifer 










Estimated groundwater resource potential is estimated for Dyke Groups C1 & C2 as approximately 

1 708 m 3 /d (refer to Table 6.4). 





Estimated groundwater resource potential is estimated for Dyke Group F as approximately 395 m 3 /d 




The estimated high growth scenario for the average annual daily water demand for Edenburg was obtained 





Sustainable Yield available from the Dolerite Dyke Groups 



(m 3 /a) 


(m 3 /d) 


Dyke Group B 405 158 1 110 

Dyke Group C1 & C2 623 492 1 708 


Dyke Group E 414 161 1 135 

Dyke Group F 144 056 395 

Total 2 073 056 5 680 

Assumptions: 









Dyke Group 

Name 

Dyke Group A 

Assumptions: 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 



(m 3 /a) 



(m 3 /d) 

2% Recharge 9 200 000 440.7 2.0 9 81 089 222 

3% Recharge 9 200 000 440.7 3.0 13 121 633 333 


(20 mm/a) 



9 200 000 440.7 4.5 20 184 112 504 

9 200 000 440.7 5.7 25 230 049 630 

Average: 






567



Dyke Group 

Name 

Dyke Group B 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 

Table 6.4: Recharge Volume Calculation Scenarios for Dyke Group C1 & C2 




(m 3 /a) 



(m 3 /d) 

2% Recharge 18 000 000 440.7 2.0 9 158 652 435 

3% Recharge 18 000 000 440.7 3.0 13 237 978 652 


(20 mm/a) 



18 000 000 440.7 4.5 20 360 219 987 

18 000 000 440.7 5.7 25 450 096 1 233 

Average: 


Assumptions: 




Dyke Group 

Name 

Dyke Group C1 & C2 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 



(m 3 /a) 


1 110 



(m 3 /d) 

2% Recharge 27 700 000 440.7 2.0 9 244 148 669 

3% Recharge 27 700 000 440.7 3.0 13 366 222 1 003 


(20 mm/a) 



27 700 000 440.7 4.5 20 554 338 1 519 

27 700 000 440.7 5.7 25 692 647 1 898 

Average: 


Assumptions: 




Dyke Group 

Name 

Dyke Group D 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 



(m 3 /a) 

1 708 



(m 3 /d) 

2% Recharge 12 400 000 440.7 2.0 9 109 294 299 

3% Recharge 12 400 000 440.7 3.0 13 163 940 449 


(20 mm/a) 



12 400 000 440.7 4.5 20 248 151 680 

12 400 000 440.7 5.7 25 310 066 849 

Average: 


Assumptions: 




765



Dyke Group 

Name 

Dyke Group E 

Assumptions: 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 




(m 3 /a) 



(m 3 /d) 

2% Recharge 18 400 000 440.7 2.0 9 162 178 444 

3% Recharge 18 400 000 440.7 3.0 13 243 266 666 


(20 mm/a) 



18 400 000 440.7 4.5 20 368 224 1 009 

18 400 000 440.7 5.7 25 460 098 1 261 

Average: 





Dyke Group 

Name 

Dyke Group F 

Assumptions: 




(m 2 ) 


(mm/a) 

Recharge 

Percentage 

(%) 

Recharge 

(mm/a) 



(m 3 /a) 


1 135 



(m 3 /d) 

2% Recharge 6 400 000 440.7 2.0 9 56 410 155 

3% Recharge 6 400 000 440.7 3.0 13 84 614 232 


(20 mm/a) 



6 400 000 440.7 4.5 20 128 078 351 

6 400 000 440.7 5.7 25 160 034 438 

Average: 





395


Figure 6.6: Locality Map of the Delineated Dolerite Dyke Groups near Edenburg as utilised for the Groundwater Resource Potential Estimation 



Figure 6.7: Locality Map of the Estimated Mini-Catchments of the Dyke Groups near Edenburg 









Susters Area. 

The groundwater resource potential is calculated by utilising the above mentioned geometric mean of 

60.48 m 3 /d per borehole or 2.1 L/s per borehole based on an 8-hour pump cycle and 16-hour recovery 

period per day. The length of the potential structures were taken into account whereby a borehole was 

spaced on the structure every 250 metres. Therefore the number of the boreholes that can be spaced on 

the structure multiplied by the geometric mean (2.1 L/s over 8-hours a day) is equal to the estimated 

groundwater resource potential of the dolerite dyke structure. 






Area). 











The groundwater resource potential for Dyke Group C1 & C2 is estimated at 2 964 m 3 /d. The 

number of dykes of the dolerite group is 10 with a combined length of 15.96 km upon, which 49 

potential boreholes are spaced for calculation purposes. 







The groundwater resource potential for Dyke Group F is estimated at 544 m 3 /d. The number of 








calculations 

Dyke Group 

Name 


Number of 

Dykes 

Total Length 

of Dykes 

(km) 


Boreholes 




(m 3 /d) 

A 2 6.28 21 1 270 

B 3 7.40 23 1 391 

C1 7 9.56 29 1 754 

C2 3 6.40 20 1 210 

D 6 6.29 16 968 

E 4 10.67 35 2 117 

F 2 3.34 9 544 

Total 27 49.94 153 9 253 

Assumptions: 

















1 270 m 3 /d. 


1 391 m 3 /d. 

The groundwater resource potential for Dyke Group C1 & C2 is estimated in the order of between 

1 708 to 2 964 m 3 /d. 


986 m 3 /d. 


2 217 m 3 /d. 


544 m 3 /d. 
















the Costing does not make provision for Surface Infrastructure such as Electrical 


Dyke Group 

Name 

Number of 


Developed 

Esti m ate d 

Potential 

Yield 

(m 3 /d) 


Geophysical & 





Boreholes 

Aquifer Test 


Boreholes 

Pumping 


Pump House 




extensively in a 10 -15 km radius around the community of Edenburg. The hydrocensus was undertaken 

by means of aerial photographs. Nine irrigation pivots were identified to the north and north east of 

Edenburg (refer to Figure 6.8). The coordinates of the irrigation pivots can be viewed in Table 6.10. 


Total C ost of 


(Excl. Vat) 

Dyke Group A 21 567 - 1 270 R 462 000.00 R 1 050 000.00 R 462 000.00 R 525 000.00 R 1 365 000.00 R 3 864 000.00 

Dyke Group B 23 1 110 - 1 391 R 506 000.00 R 1 150 000.00 R 506 000.00 R 460 000.00 R 1 495 000.00 R 4 117 000.00 

Dyke Group C 49 1 708 - 2 964 R 1 078 000.00 R 2 450 000.00 R 1 078 000.00 R 980 000.00 R 3 185 000.00 R 8 771 000.00 

Dyke Group D 16 765 - 968 R 352 000.00 R 800 000.00 R 352 000.00 R 320 000.00 R 1 040 000.00 R 2 864 000.00 

Dyke Group E 35 1 135 - 2 117 R 770 000.00 R 1 750 000.00 R 770 000.00 R 700 000.00 R 2 275 000.00 R 6 265 000.00 

Dyke Group F 9 395 - 544 R 198 000.00 R 450 000.00 R 198 000.00 R 180 000.00 R 585 000.00 R 1 611 000.00 

Total Cost R 27 492 000.00 


borehole fields and do not include the cost of the surface infrastructure such as the electrical supply lines and pipeline networks etc.





Eas t S ou th 

Pivot A 25.84994 -29.59282 

Pivot B 25.85691 -29.59724 

Pivot C 25.87338 -29.59809 

Pivot D 25.87781 -29.60397 

Pivot E 25.86964 -29.60240 

Pivot F 25.88190 -29.60658 

Pivot G 25.97311 -29.66183 

Pivot H 25.97112 -29.67044 

Pivot I 25.96603 -29.67324 


streams (refer to Figure 6.8). Therefore it is more likely that these irrigation pivots utilised surface water 

than groundwater. It is recommended that these areas be investigated to confirm the observation. 

Groundwater is also utilised by many farmers for domestic purposes at their farmsteads. Groundwater 

uses may include, drinking water purposes, washing of clothes and food preparation as well as watering of 

the farmstead gardens. 



Figure 6.8: Locality Map of the Potential High Groundwater Abstraction Areas in the Vicinity of Edenburg. Note that the Irrigation Pivots are situated next to the Riet River and other Non-Perennial Streams. Therefore it is 

more likely that these Pivots utilised Surface Water than Groundwater. It is recommended that these areas be investigated to confirm the observation 





CATCHMENT 


The study area is also located in Drainage Area C, Quaternary sub-catchment C51C. 

CLIMATE 






(Rainfall Station Gauge No.: 0230 764, Edenburg Police Station, Surface Water Resources of South Africa, 

1990). 

GEOLOGY 

The geology of the Edenburg district consists of the Karoo Super Group geology and more specifically of 

the Beaufort Group and Adelaide Subgroup. In general the sedimentary rocks are classified as blue-grey 

and purple mudstone interbedded with yellow sandstone and siltstone. 



GENERAL AQUIFER INFORMATION OF THE EDENBURG DISTRICT 


The groundwater component of river flow (base flow) is negligible in the Edenburg district. The 


between 8 – 15 m. The mean annual recharge of the area are between 15 - 20 mm/a. 

In general the recommended drilling depths are 20 to 30 metres or deeper (50 m) for the study area. The 

storage types of the aquifer quantified as fractures restricted principally to a zone below the groundwater 

level. Pores in disintegrated / decomposed, partly decomposed rock and fractures which are principally 

restricted to a zone directly below the groundwater level. Storage coefficient in order of magnitude for the 

study area is 0.001 to 0.01. 






The aerial photo interpretation of the Edenburg study area revealed 36 potential dolerite dyke structures 





located on the sedimentary rocks of the Adelaide Subgroup (Beaufort Group) of the Karoo Supergroup. 



The green and blue area on the aerial magnetic contour map denotes sedimentary rocks. Dolerite 

intrusives such as dykes and sill structures are denoted as the yellow, red and pinkish / purple areas of the 

aerial magnetics map. 






The geological map interpretation of the Edenburg study area revealed 36 potential dolerite dyke 









geology. 
















groups. This method is only a rough estimation of potential sustainable yields due to that the sustainability 

of the intrusive structure is a function of the capture zone, which in turn entails the dynamics of the aquifer 

system (The Water budget Myth Revisited; Why Hydrogeologist Model, Bredehoeft, 2002). The main to 

tool for investigating the capture zone and aquifer dynamics is the numerical groundwater model. 

Unfortunately not enough geohydrological information exists in terms of aquifer parameters to construct 

such a model. Therefore only rough estimation can be made regarding the groundwater resource potential. 


follows: 

Estimated groundwater resource potential is estimated for Dyke Group A as approximately 567 m 3 /d. 


m 3 /d. 



Estimated groundwater resource potential is estimated for Dyke Groups C1 & C2 as approximately 

1 708 m 3 /d. 



m 3 /d. 

Estimated groundwater resource potential is estimated for Dyke Group F as approximately 395 m 3 /d. 

The estimated high growth scenario for the average annual daily water demand for Edenburg was obtained 








Susters Area. 


L/s per borehole based on 8-hour pump cycle and 16-hour recovery period per day. The length of the 

potential structures were taken into account whereby a borehole was spaced on the structure every 250 

metres. Therefore the number of the boreholes that can be spaced on the structure multiplied by the 

geometric mean (2.1 L/s over 8-hours a day) is equal to the estimated groundwater resource potential of 

the dolerite dyke structure. 



An average geometric mean sustainable yield of 2.1 L/s with an 8-hour pump schedule and a 14 

recovery period per borehole (Geometric mean average obtained from borehole fields of Petrusburg, 

Philipstown, Edenville, Colesberg, Igomotseng, Winburg, Brandfort and the Drie Susters Area). 











The groundwater resource potential for Dyke Group C1 & C2 is estimated at 2 964 m 3 /d. The 

number of dykes of the dolerite group is 10 with a combined length of 15.96 km upon, which 49 

potential boreholes are spaced for calculation purposes. 









The groundwater resource potential for Dyke Group F is estimated at 544 m 3 /d. The number of 









1 270 m 3 /d. 


1 391 m 3 /d. 

The groundwater resource potential for Dyke Group C1 & C2 is estimated in the order of between 

1 708 to 2 964 m 3 /d. 


986 m 3 /d. 


2 217 m 3 /d. 

The groundwater resource potential for Dyke Group F is estimated in the order of between 395 to 544 

m 3 /d. 













A high groundwater abstraction area hydrocensus was conducted by GHT Consulting to determine if 

groundwater is utilised extensively in a 10 -15 km radius around the community of Edenburg. The 

hydrocensus was undertaken by means of aerial photographs. Nine irrigation pivots were identified to the 

north and north east of Edenburg. 


streams. Therefore it is more likely that these irrigation pivots utilised surface water than groundwater. It is 











The desktop study indicate that it is viable to further investigate the groundwater resources of Edenburg 

based on the numerous potential dolerite dykes observed in the vicinity of Edenburg. It is recommended 







aquifer; 





7. REFERENCES 

BREDEHOEFT, JD (2002) The Water Budget Myth Revisited: Why Hydrogeologist Model, Vol. 40, No. 4 – 

Groundwater – July – August 2002 on pages 340 – 345. 

MIDGLEY DC, PITMAN WV & MIDDLETON BJ (1994) Surface Water Resources of South Africa, Volume II 

Appendices, WRC Report No. 298/2.1/94 and the Department of Water Affairs and Forestry (DWAF). 

MIDGLEY DC, PITMAN WV & MIDDLETON BJ (1994) Surface Water Resources of South Africa, Volume II 

Book of Maps, WRC Report No. 298/2.2/94 and the Department of Water Affairs and Forestry (DWAF). 

ROUX AT, Geophysical Field Manual for Technicians, No. 1, The Magnetic Method, South African 

Geophysical Association. 

SCHULZE RE, MAHARAJ M, LYNCH SD, HOWE BJ & MELVIN-THOMSON B (1997) South African Atlas 

of Agrohydrology and –Climatology. WRC Report No. TT82/96. 

WOODFORD AC & CHEVALLIER (Editors) (2002) Hydrology of the Main Karoo Basin: Current Knowledge 

and Future Research Needs. WRC Report No. TT179/02.

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