INFORMATION DOCUMENT - DWA Home Page
INFORMATION DOCUMENT - DWA Home Page
INFORMATION DOCUMENT - DWA Home Page
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This document is intended as a<br />
means for sharing information<br />
about the process adopted by the<br />
Lesotho Highlands Development<br />
Authority (LHDA) for developing<br />
a policy for the release of water<br />
into downstream river courses<br />
(referred to as instream flow<br />
requirements (IFR)) for the Phase<br />
1 dams of the Lesotho Highlands<br />
Water Project in Lesotho.<br />
It also informs readers as to how<br />
they may participate in the public<br />
consultation process for the<br />
development of the policy.<br />
This document:<br />
❏ Explains the context for and<br />
need for an IFR policy<br />
❏ Gives a brief introduction to the<br />
theory behind IFR and the way in<br />
which scientists go about instream<br />
flow assessments (IFA) and<br />
❏ Indicates where readers may<br />
obtain further information and how<br />
they may participate in the<br />
process.<br />
LESOTHO HIGHLANDS WATER PROJECT<br />
Development of a Policy for Instream Flow Requirements<br />
PURPOSE OF THIS<br />
<strong>DOCUMENT</strong><br />
Senqunyane<br />
<strong>INFORMATION</strong> <strong>DOCUMENT</strong><br />
Republic of South Africa<br />
Republic of South Africa<br />
Senqu<br />
KINGDOM OF LESOTHO<br />
Senqu<br />
Malibamatso<br />
MASERU<br />
Mohale's Hoek<br />
IFR 6 @ Seaka Bridge<br />
IFR 7 @ Marakabei<br />
IFR 8 @ u/s Senqu confluence<br />
Quthing<br />
Matsoku<br />
Butha Butha<br />
IFR 2 @ Katse<br />
Thaba Tseka<br />
IFR 1 @ Seshote<br />
IFR 5 @ Whitehills<br />
IFR 3 @ Paray<br />
IFR 4 @ Sehonghong<br />
Qacha's Nek<br />
IFR Sites<br />
IFR "Super Sites"<br />
North<br />
0 20 40<br />
Kilometres<br />
Republic of South Africa<br />
KEY<br />
LHWP Dams (extant and planned)<br />
Border with RSA<br />
The Lesotho Highlands Water Project (LHWP) was established by Treaty between<br />
the Governments of Lesotho and South Africa in 1986. The purpose of this joint<br />
undertaking was to transfer water from the highlands of Lesotho to the Vaal River<br />
catchment, to augment water supplies to South Africa and to generate hydropower<br />
for Lesotho.<br />
The LHWP, one of the most ambitious water transfer schemes in the world,<br />
was designed to be developed in four phases. If developed in full, the Project<br />
would comprise 5 large dams in the upper catchments of the Orange River system,<br />
with all the project infrastructure, except for part of the transfer tunnels and<br />
discharge facilities, being located in Lesotho.<br />
To date, the implementation of Phase 1 has been virtually completed. Phase<br />
1A, comprising the largest of the dams, Katse on the Malibamats’o River, the<br />
transfer tunnels to RSA, Muela tail pond and the Muela Hydropower Station, was<br />
commissioned in 1998. Phase 1B is due for completion during 2003, with the<br />
inundation of Mohale Dam scheduled to commence in October 2002. Phase 1B<br />
consists of Mohale Dam on the Senqunyane River, Matsoku Weir on the Matsoku<br />
River, and transfer tunnels from Mohale and Matsoku to Katse Dam.<br />
The original demand predictions indicated that Phase 2 development would<br />
follow immediately on completion of Phase 1. However, circumstances, including<br />
a slower rate of growth in demand in South Africa, have conspired to result in the<br />
certain delay of Phase 2. Thus, the process for developing a policy for the release<br />
of water into downstream river courses (referred to as instream flow requirements<br />
(IFR)) concerns only Phase 1.<br />
Rivers<br />
1
❏ Treaty commitments to<br />
environmental management,<br />
maintaining livelihoods and<br />
compensating for losses<br />
❏ The need for a scientific<br />
approach to and policy for<br />
managing releases and<br />
downstream impacts<br />
❏ Lesotho seeks to comply with<br />
the Treaty and protect the interests<br />
of its people<br />
❏ South Africa seeks to comply<br />
with the Treaty and South African<br />
water law<br />
❏ An IFR policy will ensure some<br />
water is reserved for ecosystems<br />
and communities downstream of<br />
control structures<br />
❏ The IFR policy will ensure that<br />
reserved water is made available<br />
to the ecosystem and communities<br />
at appropriate times<br />
❏ The IFR policy will outline<br />
standards or indicators for the<br />
management of the target river<br />
health.<br />
MOTIVATING<br />
FACTORS<br />
Why Do We Need an IFR Policy?<br />
Water Releases: Design and Practice<br />
When the LHWP was designed in the 1970s and 1980s, awareness of environmental<br />
issues in general, and downstream environmental and social impacts of large dams<br />
in particular, was much lower than it is today. Nevertheless, environmental issues<br />
were embedded in the Treaty (see Box below) and the relevant Treaty articles were<br />
given effect through the implementation of Environmental Action Plans (EAPs)<br />
for both Phases 1A and 1B. The difference between 1A and 1B was that Phase 1B<br />
environmental and socio-economic baseline studies were done in advance of<br />
construction/implementation in the case of Mohale Dam, whereas the Phase 1A<br />
baseline studies were being conducted while construction of the Project was already<br />
underway. Thus, the Phase 1B EAP benefited from lessons learnt in implementing<br />
Phase 1A.<br />
The Phase 1 EAPs have, to date, applied only to the dam basins and upstream<br />
catchment areas. It was the Phase 1B environmental impact assessment report in<br />
1994 that identified the need for an instream flow assessment, to investigate<br />
environmental and social impacts downstream of both dams and to design measures<br />
to mitigate them or compensate for them.<br />
As far as management of the downstream environment goes, operation of dam<br />
releases under the Treaty articles (see box below) is the only operational mode<br />
currently approved by Project authorities. The Treaty specified compensation flows<br />
amounting to between 2% and 3% of Mean Annual Runoff (MAR). The Project<br />
was designed and, for the most part, constructed, on the basis of the intended<br />
transfer of approximately 93% of the water yield (MAR) from the rivers above<br />
the LHWP structures. From 1996-2001, releases or flows from Katse were<br />
substantially in excess of these parameters—averaging 32% of MAR, with a low<br />
of 4,2% MAR in 1999 and a high of 61,6% MAR in 2001 (see box below).<br />
Currently, to protect the river until an IFR Policy is in place, Katse Dam and<br />
the Matsoku weir are being operated to release 750 litres per second (l/s) and 600<br />
l/s, respectively.<br />
Other than control of releases, to date no downstream management or mitigation<br />
measures have been undertaken, except for the regular monitoring of water quality<br />
in downstream rivers.<br />
1996 64.0%<br />
1997 30.5%<br />
Katse Releases (% MAR)<br />
1998 27.4%<br />
1999 4.2%<br />
LHWP TREATY ENVIRONMENTAL AND SOCIAL COMMITMENTS<br />
2000 6.5%<br />
2001 61.6%<br />
Environmental considerations were incorporated into the Project from the beginning, notably as legally binding articles in<br />
the Treaty. The main provision for environmental matters in the Treaty (embodied in Article 15) states:<br />
“The Parties agree to take all reasonable measures to ensure that the implementation, operation and maintenance of<br />
the Project are compatible with the protection of the existing quality of the environment and, in particular, shall pay due<br />
regard to the maintenance of the welfare of persons and communities immediately affected by the project”.<br />
Furthermore, Article 7(18) of the Treaty enjoins the Lesotho Highlands Development Authority (LHDA, the body set up<br />
to implement the Project and be responsible for its operation and maintenance), to:<br />
“effect all measures to ensure that members of the local communities in the Kingdom of Lesotho, who will be affected<br />
by flooding, construction works or similar project-related causes, will be able to maintain a standard of living not inferior to<br />
that obtaining at the time of first disturbance, provided that such Authority shall effect compensation for any loss to such<br />
member as a result of such project-related causes not adequately met by such measures”.<br />
The Treaty, in recognition of downstream needs, specified Phase 1 downstream flows (the “Treaty Minimum Releases”)<br />
of not less than 500 l/s and 300 l/s from Katse and Mohale dams, respectively. It made no mention of the Matsoku weir.<br />
2
PUBLIC DISCLOSURE<br />
AND INVOLVEMENT<br />
Public disclosure and input into<br />
policy development is the policy<br />
of the LHDA and a World Bank<br />
requirement. It involves the use of<br />
two-way communication:<br />
❏ May-June 2002: a pilot<br />
consultation process was<br />
conducted, in 16 potentially<br />
affected villages downstream of<br />
Phase 1 structures in a 5 km wide<br />
corridor each side of the river<br />
❏ May-August: meetings with the<br />
Principal Chiefs of Lesotho are an<br />
important matter of protocol<br />
❏ June-August: extension of this<br />
process to all downstream villages<br />
in potentially significantly affected<br />
river reaches in a 5 km wide<br />
corridor each side of the river (IFR<br />
Sites 1, 2, 3 and 7)<br />
❏ Public disclosure: this document<br />
represents the first step in a<br />
process which will inform the<br />
broader interested and/or affected<br />
community about the IFR policy<br />
❏ Public consultation: the posting<br />
of the Draft IFR Policy on websites<br />
and in libraries, in early August<br />
2002 for 30 days, for the purposes<br />
of public comment<br />
❏ Public notification: the posting<br />
of the final IFR Policy and a<br />
Response Report, to notify<br />
stakeholders of the final Policy and<br />
to explain how LHDA has<br />
responded to concerns.<br />
What is an Instream Flow<br />
Requirements Policy?<br />
Instream flow requirements (IFR) refer to the amount, quality and timing of water<br />
released through or over dams and associated structures to meet riverine ecosystem<br />
and social needs in the reaches downstream of dams. The objective is to mitigate<br />
the impacts of such structures on the downstream environment and people.<br />
Downstream affected people have to be consulted about the potential impacts of<br />
the project on their livelihoods and compensated for any losses, in such a way as<br />
to restore those livelihoods.<br />
The approach adopted by LHDA, and endorsed by the Lesotho Highlands<br />
Water Commission and the World Bank, was to focus on the obligations contained<br />
in the Treaty and in the World Bank Loan Agreement to mitigate the adverse effects<br />
of the dam on the downstream environment and people.<br />
The IFR Policy will emphasize the establishment of a pattern of target water<br />
releases—base flows and floods, in wet, average and dry years—that will ensure<br />
that adverse impacts on the downstream environment do not exceed agreed levels<br />
of river health conditions.<br />
In contrast to the impact evaluations undertaken for areas upstream of the<br />
LHWP dams, which typically dealt with largely significant impacts on a relatively<br />
small number of people (a few hundred), downstream evaluation has had to deal<br />
with relatively small impacts on a large number of people (tens of thousands) in<br />
an area that had not previously been studied.<br />
This approach - managing the river rather than managing the dam – makes the<br />
ecological health of the river and the welfare of downstream communities key<br />
elements in decisions regarding the allocation and use of water. It also paves the<br />
way for establishing a firm basis for determining losses of and compensation for<br />
downstream aquatic and riparian resources.<br />
It will lead to an IFR policy that covers the geographic scope of the policy’s<br />
interventions, a monthly release schedule that specifies base flows and flood<br />
releases for wet, normal and dry years, dam operating procedures, monitoring, the<br />
principles of the social mitigation and compensation process, record keeping,<br />
audits, disclosure and consultation and the budget commitments required to operate<br />
the policy.<br />
Senqunyane River. (Photo: George van der Merwe)<br />
3
It is important to note that, given the<br />
scientific state of the art regarding<br />
environmental flow requirement studies<br />
and the forecasting of potential impacts,<br />
the results of the studies should be<br />
interpreted as providing guidance to<br />
inform the formulation of a policy and<br />
not as exact predictions of what may<br />
happen.<br />
Uncertain future rainfall patterns, the<br />
specific way in which the river ecology<br />
may respond to changed hydrological<br />
and hydraulic conditions, and the<br />
adaptation strategies of the downstream<br />
riparian plants and animals, will all<br />
interact to create a new ecology and,<br />
potentially, new socio-economic<br />
patterns.<br />
This is why it is important to design a<br />
policy that is adaptable to the emerging<br />
reality on the ground and to monitor<br />
the environmental and social conditions<br />
as they evolve, in order to do the<br />
maximum to ensure river health and the<br />
livelihoods of the affected people.<br />
The Outcome<br />
The culmination of all these studies<br />
will be the formulation and approval<br />
by the Project Authorities of an IFR<br />
Policy, which will<br />
❏ commit the LHDA to a target<br />
release regime from each of Phase<br />
1’s dams, namely, Katse and Mohale<br />
Dams and Matsoku Weir;<br />
❏ commit the LHDA to specified<br />
principles of mitigation of impacts<br />
and compensation for losses;<br />
❏ establish the basis for the<br />
assessment of environmental and<br />
social losses and procedures for<br />
claiming compensation;<br />
❏ set out the details of a monitoring<br />
program which will support the<br />
release regime, compensation and<br />
mitigation policy; and<br />
❏ establish a regular program to<br />
review the policy in the light of the<br />
results of the monitoring studies.<br />
IFR STUDIES undertaken<br />
by LHDA<br />
Contracts 648 and 678<br />
The decision to appoint a consultant to undertake a thorough assessment of<br />
downstream impacts was taken during 1996. Metsi Consultants, a joint venture<br />
of SMEC International of Australia and Southern Waters Ecological Research and<br />
Consulting of South Africa, was contracted to undertake IFR studies of the Project<br />
under LHDA.<br />
Contract 648, conducted between 1997 and 2000, produced 22 separate reports.<br />
The terms of reference for the study required consideration of the combined effects<br />
of Phases 1 and 2. The study area included the Malibamats’o River downstream<br />
of Katse, the Matsoku River (tributary of the Malibamats’o) downstream of Matsoku<br />
Weir, the Senqunyane River downstream of Mohale, to their respective confluences<br />
with the Senqu River, and the middle and lower reaches of the Senqu River, to the<br />
border with South Africa. The study involved a wide range of specialists, from<br />
physical and biological scientists to human and animal health and socio-economic<br />
specialists.<br />
When it became clear that a significant delay in the implementation of Phase<br />
2 was probable, Metsi Consultants was asked to assess the situation without the<br />
effects of Phase 2. This exercise was undertaken as LHDA Contract 678, the final<br />
reports of which have recently been completed. These studies have analyzed the<br />
downstream rivers’ responses to reduced flows and have predicted a range of<br />
impacts, the overall trends of which are shown in boxes on succeeding pages.<br />
Upstream of Katse Dam. (Photo: George van der Merwe)<br />
4
Instream Flow Requirements: Theory and Practice<br />
The analysis of environmental flow requirements is based on the premise that river flow is the primary determinant of a number<br />
of physical and biological parameters in aquatic and riparian ecosystems. A crucial relationship exists between river flow or<br />
discharge (analyzed as a number of components, notably base flows and floods), hydraulics and geomorphology. The volume<br />
of flow determines the depth and size of the river and a number of ecological processes are linked to this.<br />
An IFR is a description of a modified flow regime, invariably due to the presence of a control structure in the river, such as a<br />
dam or weir, that is linked to a description of the condition or health of the river that this flow might be expected to produce.<br />
Furthermore, because the characteristics of a river change as one moves downstream, flow-ecology relationships change too.<br />
One must, therefore, establish different relationships for each affected river reach. Thus, IFR studies focus their analyses on<br />
carefully selected IFR Sites, representative of particular river reaches (the LHWP IFR Phase 1 Sites are shown in the map on<br />
<strong>Page</strong> 1).<br />
In Southern Africa, the Building Block Methodology (BBM) has been developed and used for the assessment of IFRs. The BBM<br />
requires that a desired future state of the river be identified first; then the scientists<br />
construct the seasonal flow regime, comprising base flows, small and large floods,<br />
required to maintain that desired state. In the case of the LHWP, the in-stream<br />
flow assessment (IFA) was needed to assist in determining a desired future state,<br />
not the other way round, so a different approach was developed. This Downstream<br />
Response to Imposed Flow Transformations (DRIFT) methodology allows the<br />
biophysical and socio-economic consequences of flow changes to be determined<br />
for a number of potential future flow regimes. That is, it is a scenario-based approach.<br />
A Caveat. It is important to bear this in mind when reading the findings of these<br />
studies, that the findings are based on a specific set of conditions defined as<br />
the scenario and not on actual conditions. The findings are, thus, all predictions<br />
and are only as good as the primary information or databases that support them.<br />
For instance, the assessment of changes in riparian vegetation patterns requires<br />
a detailed knowledge of the auto-ecology of individual species, but such data<br />
are not available for the Highlands environment and species specifically, although<br />
experience in other systems will be applicable to some extent. The results of<br />
these studies must, therefore, be interpreted with caution; they must not be viewed<br />
as fact, but rather as the best predictions currently available. Careful monitoring<br />
of the system, after implementation of the IFR Policy, will be essential to establish<br />
the actual system responses, to establish actual losses to resource users and to<br />
permit adaptation as necessary.<br />
The LHWP IFR analysis proceeded on the basis of eight IFR sites in the four rivers<br />
of interest (see Map). Detailed, holistic field characterizations of each site field<br />
were undertaken over a 12-month period to establish a baseline, although a preproject<br />
baseline for the Malibamats’o River could not be established, due to the<br />
presence of Katse Dam. The DRIFT methodology was then used to predict the<br />
effects on different biophysical system components. Four modified flow regimes<br />
were hypothesized, based on design and operational constraints and the nature of<br />
the rivers. Finally, the consequences of the predicted biophysical changes on the<br />
human Population at Risk were analyzed and the costs of potential resource losses<br />
were calculated.<br />
Bringing all the<br />
elements together<br />
The final phase of policy development<br />
will be to assess the trade-offs between<br />
river health, communities and the<br />
implications of different release options<br />
in terms of lost benefits to the two<br />
countries – all within the context of the<br />
Treaty requirement that the project<br />
should “pay due regard to the<br />
maintenance of the welfare of persons<br />
and communities”, and “take all<br />
reasonable measures to ensure…the<br />
protection of the existing quality of the<br />
environment”. If a purely financial<br />
approach were to be taken, the project<br />
would maximize revenue at the expense<br />
of the downstream environment and<br />
communities; if a purely environmental<br />
approach were to be taken, the project<br />
would release as much water as was<br />
necessary to protect the environment<br />
and communities at a high cost in terms<br />
of lost revenue. The policy development<br />
process seeks an intermediate position<br />
that will represent a fair and reasonable<br />
balance between the two extreme<br />
positions.<br />
5
YOUR INVOLVEMENT<br />
Your involvement is very important<br />
to us. While at this stage we seek<br />
to inform, not to solicit comment,<br />
we urge you to submit comments<br />
on the Draft IFR Policy when it is<br />
released.<br />
Details about the venues where<br />
documentation is available, and<br />
where the Draft IFR Policy will<br />
be posted are provided on the<br />
next page.<br />
WHO TO CONTACT<br />
ABOUT THIS PROJECT<br />
Should you wish to submit<br />
comments, please do so to the<br />
following email address<br />
lhwp@lhda.org.ls<br />
Or by fax to +266 325775,<br />
for the attention of<br />
Mr R Maphetla<br />
Chief Executive Officer<br />
LHDA<br />
PO Box 7332<br />
Maseru 100<br />
Lesotho<br />
Should you wish to discuss<br />
anything relating to the IFR policy<br />
process, or to obtain further<br />
information, do not hesitate to<br />
contact the following persons at<br />
LHDA:<br />
Ms. M. Mothepu<br />
Deputy General Manager ESSG<br />
Phone:<br />
+266 835 0825<br />
+266 85 0679 (Cell phone)<br />
Mr. Taole Tesele<br />
IFR Co-ordinator<br />
Phone:<br />
+266 835 0731<br />
+266 85 2143 (Cell phone)<br />
Description of the<br />
Lesotho Highlands<br />
Lesotho is a land-locked country 30 355km 2 in extent. The eastern two-thirds,<br />
called the Highlands, are formed by the rugged Drakensberg and Maloti ranges,<br />
which form a high, dissected plateau with an average elevation of about 2 500<br />
metres above sea level (masl). The narrow river valleys are steep-sided; the<br />
landscape is one of deeply incised valleys and peaks. The Senqu (Orange) River<br />
drains the eastern and southern sectors and has several large tributaries, including<br />
the Malibamats’o, Senqunyane and Matsoku rivers, which are the locations for<br />
LHWP structures (see map).<br />
Highland catchments are characterised by high rainfall, temperate summers<br />
and long, cold winters, and they have high water yields due to rapid runoff from<br />
the steep slopes. Rainfall occurs predominantly as thunderstorms of high intensity<br />
and short duration. The nature of the rainfall and the rapid movement of water off<br />
the steep slopes and thin soil results in a quick drainage reaction time. Highly<br />
variable, but distinct wet, dry and transitional seasons are identifiable from<br />
hydrological records. The wet/rainy season extends from December to March,<br />
while the dry season usually extends from June through September.<br />
Grasslands and shrublands dominate highland vegetation; wetlands occur in<br />
all drainage lines. Vegetation zones along rivers typically have a higher biodiversity<br />
than elsewhere and a higher proportion of woody vegetation, both indigenous and<br />
exotic species. The wild animal communities of Lesotho are distinctive, with<br />
several endemic species, but wildlife densities are very low due to heavy, uncontrolled<br />
exploitation.<br />
The human population along the rivers downstream of the LHWP structures<br />
within Lesotho live in small villages, with a small proportion living in larger<br />
settlements such as Marakabei. It has been estimated that some 8 300 households<br />
in a 5km corridor on each side of the downstream rivers may be significantly<br />
affected by Phase 1 of the LHWP. While foreign employment in South Africa<br />
represents an important, although declining, source of income, rural people are<br />
heavily dependent on local resources for their livelihood. Agriculture is an important<br />
source of livelihood, but agricultural plots are constrained in size by topography<br />
and soil depths. Relatively more and better land is available along the Matsoku<br />
and upper Senqunyane Rivers than along the deeply incised Malibamats’o and<br />
upper Senqu rivers. The nutrition status of local people, especially children, is low,<br />
even by Lesotho rural standards, and there is a high incidence of childhood<br />
infectious diseases as well as water-related diseases. Livestock are abundant in<br />
the area (estimated populations of 68 000 catttle, 78 000 sheep, 131 000 goats and<br />
24 000 horses and donkeys).<br />
IFR Study Scenarios<br />
Minimum Degradation Scenario<br />
This scenario was developed as a hypothetical condition, in which maintenance<br />
of the rivers in a state of minimal degradation from their current condition was the<br />
main objective and only thereafter would water delivery needs be catered for (ie<br />
transferred to SA). It assumed that 60-65% of Mean Annual Runoff would be<br />
released to downstream ecosystems. This scenario allowed specialists to consider<br />
interactively baseline conditions relative to flow levels and to establish the flows<br />
below which significant ecological and physical changes could be anticipated. It<br />
should be noted that this scenario is not technically achievable due to design<br />
constraints on the structures<br />
6
WHERE TO GET<br />
MORE <strong>INFORMATION</strong><br />
The 3 key reports:<br />
❏ Metsi Consultants (2002) Report<br />
678-F-001, Summary of Main<br />
Findings for Phase 1 Development<br />
❏ Metsi Consultants (2002) Report<br />
678-F-002, Additional Scenarios and<br />
Production of a New Final Report<br />
(Vol. II)<br />
❏ S. Klasen (2002) The Costs and<br />
Benefits of Changing Instream Flow<br />
Requirements<br />
are available on the following<br />
websites:<br />
❏ www.lhwp.org.ls.<br />
❏ www.lesotho.gov.ls<br />
❏ www.dwaf.gov.za<br />
❏ www.sametsi.com<br />
Hard copies of these reports are<br />
lodged for public inspection at<br />
the following venues:<br />
❏ LHDA Library, 3rd Floor, Post<br />
Office Building, Kingsway, Maseru,<br />
Lesotho<br />
❏ National Environmental<br />
Secretariat Library, Post Office<br />
Building, Maseru<br />
❏ National University of Lesotho<br />
Library, Roma, Lesotho<br />
❏ <strong>DWA</strong>F Library, 3rd Floor Sedibeng<br />
Bldg, Schoeman St, Pretoria<br />
❏ World Bank office, Pro-Equity<br />
Court, 1250 Pretorius Street,<br />
Pretoria<br />
❏ University of Cape Town Library,<br />
Rondebosch, Cape Town<br />
❏ Public Information Center, World<br />
Bank, 1818 H Street NW,<br />
Washington, DC<br />
Should you wish to read further,<br />
a full set of Metsi Consultants<br />
Contract 648 reports are lodged<br />
at:<br />
❏ LHDA Library, 3rd Floor, Post<br />
Office Building, Kingsway, Maseru,<br />
Lesotho<br />
❏ <strong>DWA</strong>F Library, 3rd Floor,<br />
Sedibeng Bldg, Schoeman St,<br />
Pretoria, South Africa<br />
❏ National University of Lesotho<br />
Library, Roma, Lesotho<br />
Treaty Minimum Release Scenario<br />
This is the scenario generated by application of the minimum release conditions<br />
specified in the Treaty and is at the opposite end of the range from Minimum<br />
Degradation in terms of water requirements. Conceptually, the scenario differs<br />
from that above in that the volumes of delivery water are first specified and<br />
consequential river conditions then assessed.<br />
Design Limitation Scenario<br />
This is a scenario based on the practical limitations of flow releases imposed by<br />
the designs of the Phase 1 structures. In terms of volumes of water releases, it is<br />
between the above two scenarios.<br />
Fourth (Intermediate) Scenario<br />
This scenario was selected to fall between the Treaty Minimum and Design<br />
Limitation scenarios and to provide a reference point between the former (legally<br />
defined and highest water delivery, but most severe environmental and socioeconomic<br />
impacts) and the latter (possible within engineering constraints, but<br />
likely to have high impacts on water and revenues).<br />
Summary of Findings<br />
Hydrological changes<br />
The Table below gives a global picture of the hydrological changes that are predicted<br />
to occur under each of the four scenarios. It is from the changes in the river<br />
hydrology or flow regime that all other predicted changes are derived. This overview<br />
presents the overall amount of water available to downstream ecosystems on an<br />
annual basis, as a proportion of mean annual runoff (MAR), this being an estimate<br />
of the average amount of water draining from the catchment in a year.<br />
Table 1: Historical MAR, the annual volume allocated to the river and the percentage of<br />
historical MAR that this represents, under each of the four scenarios at each IFR site for<br />
LHWP Phase 1 development. Shaded sites represent reaches immediately downstream of<br />
the dams in Phase 1a and 1b<br />
IFR<br />
Site<br />
Historical<br />
MAR<br />
Minimum<br />
Degradation<br />
Scenario<br />
MCM a -l MCM a -l %MAR MCM a -l %MAR MCM a -l %MAR MCM a -l %MAR<br />
1 87 51 59 35 40 35 40 31 36<br />
2 554 366 66 22 4 184 33 97 18<br />
3 774 436 56 128 17 315 41 227 29<br />
4 1572 866 55 831 53 831 53 831 53<br />
5 1924 1194 62<br />
6 3330 2171 65<br />
Treaty<br />
Minimum<br />
Scenario<br />
Design<br />
Limitation<br />
Scenario<br />
Fourth<br />
Scenario<br />
Flows sufficient for Minimum Degradation<br />
7 355 231 65 48 13 126 35 77 22<br />
8 592 397 67 158 27 254 43 195 33<br />
Site 1 = Matsoku R, immediately downstream of Matsoku Weir (30km)<br />
Site 2 = Malibamats’o R, immediately downstream of Katse Dam (20km)<br />
Site 7 = Senqunyane R immediately downstream of Mohale Dam (90km)<br />
Site 3 = Malibamats’o R at Paray, downstream of confluence with Matsoku R (35km)<br />
Site 4 = Senqu R at Sehonghong, representing Senqu between confluences of Malibamats’o and<br />
Tsoelike rivers (125km)<br />
Site 5 = Senqu R at Whitehills, between confluences of Tsoelike and Senqunyane rivers (85km)<br />
Site 6 = Senqu R at Seaka Bridge, from confluence with Senqunyane to South African border (140km)<br />
Site 8 = Senqunyane R upstream of the confluence with the Senqu R, from confluence with Lesobeng<br />
R to the confluence with the Senqu R (40km).<br />
7
PREDICTED IMPACTS<br />
Vegetation (See also Resource Impacts)<br />
❏ Narrower vegetation zones along<br />
rivers<br />
❏ Many riparian species will be less<br />
abundant<br />
❏ Algal blooms will be more frequent<br />
❏ Some species will increase<br />
Aquatic animals<br />
❏ Increases in algal feeding invertebrate<br />
community<br />
❏ Increases in tolerant filter feeding<br />
invertebrate communities; decreases in<br />
sensitive species<br />
❏ Increases in some Simulium,<br />
(significant as stock disease vectors)<br />
❏ Increases in midges<br />
❏ Possible introduction of disease<br />
carrying snails, Planorbidae and<br />
Physidea<br />
❏ Decline of some fish species: trout,<br />
yellowfish<br />
❏ Likely extinction of the Maloti<br />
minnow in some river reaches<br />
Resource impacts<br />
❏ Decreases in shrubs and trees used<br />
for fuel and construction<br />
❏ Decrease in some medicinal plant<br />
species<br />
❏ Decrease in availability and size of<br />
fish<br />
❏ Decrease in availability of river sand<br />
❏ Decreases in availability of wild<br />
edible vegetation<br />
❏ Increase in the availability of reeds<br />
and thatching grass<br />
Socio-economic impacts<br />
❏ Immediately downstream of Katse<br />
and Mohale dams, social impacts may<br />
be critically severe under the Treaty<br />
scenario, due to resource depletion<br />
❏ Social impacts are low, however, for<br />
all sites located two or more reaches<br />
away from the structures<br />
❏ The baseline health status of the<br />
population at risk is relatively poor ;<br />
the Treaty and Fourth scenarios increase<br />
the risks of infection from moderate to<br />
severe for diarrhoeal and skin and eye<br />
diseases.<br />
Summary of findings (continued)<br />
The main significance of hydrological changes will be as follows:<br />
Low flows will be lower, both wet and dry season low flows. Low flows are<br />
important for creating different conditions in different seasons, dictating the<br />
occurrence or emergence and population densities of various species at different<br />
times of the year.<br />
Small floods will be smaller and less frequent in occurrence. They stimulate<br />
spawning in fish, flush out poor quality water, cleanse the riverbed and sort river<br />
stones by size, thereby creating different habitats. They trigger and synchronize<br />
activities as varied as upstream migrations of fish and germination of seedlings<br />
on river banks.<br />
Large floods will be almost eliminated, except for very wet periods when the dams<br />
may overtop. Large floods provide scouring flows that shape the river channel;<br />
they also trigger some of the same responses as small floods. They move and<br />
cleanse cobbles and boulders on the riverbed and deposit silt, nutrients, eggs and<br />
seeds on floodplains; they inundate backwaters, secondary channels and floodplains,<br />
recharge soil moisture levels in the banks and trigger bursts of growth in many<br />
species.<br />
Flow variability will be reduced, in daily, seasonal and annual cycles. Variability<br />
acts as a form of natural disturbance, which effectively creates temporal and spatial<br />
habitat mosaics, of areas inundated and exposed for different periods of time. The<br />
greater the habitat diversity, the greater the species diversity and the greater is<br />
ecosystem stability and resilience against unnatural perturbations.<br />
Overall Impact Rating<br />
The overall significance of the potential biophysical changes flowing from these<br />
hydrological changes was rated by Metsi for each IFR site, under each scenario,<br />
as shown in Table 2.<br />
Table 2: Reach-specific summary of the predicted combined biophysical consequences for<br />
each scenario with Phase 1 dams in place. The levels of impacts are coded as follows:<br />
white – negligible; green – low; yellow – moderate; blue – severe; red – critically severe.<br />
1<br />
2<br />
7<br />
3<br />
4<br />
5<br />
6<br />
8<br />
Reach<br />
Proximal to<br />
dam or weir<br />
Distant from<br />
dam or weir<br />
Minimum<br />
Degrradation<br />
M<br />
M<br />
L<br />
L<br />
L<br />
N<br />
N<br />
N<br />
Design<br />
Limitation<br />
** Site 1 is below Matsoku Weir, and attracts Severe and Critically Severe ratings, despite the relatively<br />
high proportion of MAR (40%) still flowing down the river, due to the extinction in the Matsoku River<br />
of the Maloti minnow. LHDA is establishing a program to protect the minnow in other Lesotho rivers.<br />
Summary Findings<br />
❏ Sites proximal to dam structures have the potential to be severely impacted<br />
under all realistic scenarios (the exception is the Minimum Degradation scenario),<br />
largely on the basis of physical in-stream habitat changes and losses of aquatic<br />
biota.<br />
❏ Consequential changes in riparian biota and resources are much less certain<br />
(see Predicted Impacts), as are changes in human and animal health vectors and<br />
agents.<br />
S**<br />
S<br />
S<br />
M<br />
L<br />
L<br />
N<br />
L<br />
Fourth<br />
S**<br />
S<br />
S<br />
M<br />
L<br />
L<br />
L<br />
L<br />
Treaty<br />
S**<br />
CS<br />
S<br />
S<br />
M<br />
L<br />
L<br />
M<br />
8
RECORDED IMPACTS<br />
Metsi Consultants did their baseline study<br />
field work during 1999, when Katse Dam<br />
was being operated at close to Treaty<br />
minimum releases, so the results gave a<br />
good indication of the kinds of conditions<br />
which might prevail under the Treaty<br />
scenario:<br />
❏ The state of both the instream and<br />
riparian habitat (“habitat integrity”) at site<br />
2 (below Katse) was rated to be less than<br />
50% (of the ‘pristine’ condition). Other<br />
sites – not affected by a dam – got scores<br />
of between 80% and 95%.<br />
❏ Water quality at site 2 was poor, there<br />
were abundant algae in the water<br />
(mountain rivers usually flow clean) and<br />
very few fish.<br />
Monitoring downstream of Katse Dam<br />
(IFR sites 2 and 3) in summer 2000/01<br />
and summer 2001/02 has shown<br />
❏ A reduction in instream river health<br />
indicators at site 2, much less so at site 3,<br />
largely due to the absence at site 2 of<br />
sensitive groups of macro- invertebrates<br />
(only tolerant groups were recorded)<br />
❏ A lack of clear geomorphologic trends<br />
(an important prediction of the IFR studies<br />
was major changes in river<br />
geomorphology), although sedimentation<br />
in some pools was observed;<br />
❏ Woody plant species have increased in<br />
number and distribution, having colonised<br />
boulder beds and sandbars, which would<br />
previously have been often covered with<br />
water. This appears to contradict the study<br />
findings, but it does not mean that the<br />
pattern will not change in the long term.<br />
❏ During summer 2002, however, river<br />
flow was very high and fish were reported<br />
to be abundant below Katse Dam.<br />
Metsi’s pilot community surveys,<br />
conducted in April and May 2002, show<br />
some communities already suffering fuel<br />
wood shortages that are not due to the<br />
project, that is, fuel wood resources are<br />
already depleted in some areas.<br />
They also report on the experience of<br />
communities regarding both reduced flows<br />
and flood conditions. Reduced flows allow<br />
their stock to cross the river, where<br />
previously they couldn’t, and encroach<br />
into other villages’ grazing lands. High<br />
flows, on the other hand, wash away trees<br />
planted by individuals.<br />
The Economics of IFRS<br />
Losses To Downstream Communities<br />
❏ The IFR study finds sizeable economic losses (in terms of use values and<br />
necessary compensation costs) to downstream communities ranging from a total<br />
of M2,9 million to M8 million annually depending on the IFR scenario chosen.<br />
It should be kept in mind, however, that the figures are estimates only, based on<br />
certain biophysical predictions, and are primarily for the purposes of scenario<br />
comparison.<br />
❏ The IFR study also finds that small increases in releases will only have a modest<br />
impact on these losses, although there are differences between the various resources<br />
and sites. Only considerable increases in IFR releases will succeed in sharply<br />
reducing the losses to downstream communities. Even in the Minimum Degradation<br />
Scenario, downstream communities do face losses for which, according to Treaty<br />
rules, they should be entitled to compensation of some form.<br />
❏ A recent pilot consultation process amongst downstream communities revealed<br />
very realistic and clear preferences for mitigation and compensation amongst<br />
potentially affected communities, from programs of assistance to replace lost<br />
resources, to flow releases, to assistance with broader development needs as<br />
mitigation for losses which would be difficult to replace directly.<br />
Revenue and Other Losses<br />
❏ While increasing IFR releases for Lesotho would reduce downstream losses,<br />
Lesotho would also lose variable water royalties and hydropower revenues, which<br />
would have a negative impact on Lesotho’s economy as a whole. For example, if<br />
the Fourth Scenario were to be adopted, the loss to the Lesotho economy would<br />
be some M17,5 million per annum at 1999 prices, or about 6% of the total revenues<br />
from the LHWP. In addition the original objective that Muela HEP would make<br />
Lesotho self sufficient in electricity, would be compromised.<br />
❏ The Klasen study of the economic impacts of the different IFR release scenarios<br />
shows that, from an economic point of view, the economic costs to Lesotho and<br />
South Africa of increasing downstream releases beyond the Treaty minimum level<br />
always outweigh the benefits for downstream communities (and, thus, the costs<br />
of compensation for losses). This is the case from the point of view of the project,<br />
of RSA and of Lesotho.<br />
❏ In other words, the lost royalty and hydropower revenues would always be<br />
greater than the economic losses to downstream communities.<br />
❏ Notwithstanding this, the overall project benefits, over the life of this project,<br />
are so large that the viability of the project is not affected by including these<br />
downstream losses, that previously had not been considered in the economic<br />
assessment of the project.<br />
❏ While the water transfer benefits of the project would be sharply reduced under<br />
the three scenarios with releases in excess of the Treaty Minimum, as would the<br />
already low rate of return of the hydropower component, they remain sizeable<br />
enough that LHWP as a whole remains viable even if IFR releases were increased.<br />
❏ Therefore in setting the IFR policy some difficult decisions and trade-offs have<br />
to be considered, and public consultation is an essential element in this process.<br />
9
PROVISIONAL LIST<br />
OF AUTHORITIES<br />
AND IAPS<br />
NATIONAL AUTHORITIES<br />
❏ Government of Lesotho<br />
❏ Ministry of Natural Resources<br />
❏ National Environmental<br />
Secretariat<br />
❏ Ministry of Finance<br />
❏ South Africa<br />
❏ Department of Water Affairs &<br />
Forestry<br />
TRADITIONAL AUTHORITIES<br />
❏ Principal Chiefs of Lesotho (24)<br />
and their community development<br />
representatives<br />
AFFECTED COMMUNITIES<br />
❏ Some 8,300 households in 338<br />
villages in a 5-km wide corridor on<br />
either side of the affected river<br />
reaches, incorporating IFR Sites 1,<br />
2, 3 and 7.<br />
LENDERS/ DONORS<br />
❏ World Bank<br />
❏ European Investment Bank<br />
❏ Development Bank of South Africa<br />
OTHER INTERESTED PARTIES<br />
❏ Lesotho Council of NGOs<br />
❏ NGOs/civic organizations/<br />
individuals in Lesotho and South<br />
Africa<br />
❏ International NGOs<br />
Should you feel strongly that any<br />
particular organizations should be<br />
made aware of this project, please<br />
do not hesitate to contact us and<br />
give us their contact details (without<br />
their contact details we will not be<br />
able to involve them, due to the tight<br />
program).<br />
Implications for IFR Policy<br />
Mitigation by flow releases: Overall<br />
❏ The Minimum Degradation scenario was always a hypothetical option, since<br />
design limitations in the dams prevent the releases being made which might achieve<br />
it. It is not, therefore, an option that can be considered for operational purposes.<br />
It has, however, been useful as a scenario against which to compare the other<br />
scenarios.<br />
Katse Releases<br />
❏ The IFR studies show that the design limitations on Katse do not allow much<br />
flexibility of release regime and that all three possible scenarios are predicted to<br />
result in “Severe” overall ecological impacts in reaches immediately downstream<br />
of the dam (Site 2).<br />
❏ The Matsoku rating of “Severe” overall impact under all three scenarios is<br />
heavily skewed by the probable extinction of one species from this river, namely<br />
the Maloti minnow. If the Maloti minnow is taken out of the equation, then<br />
Matsoku’s 600 l/s release regime will allow the downstream ecosystem to be<br />
maintained in a reasonable condition, since it will have 40% of MAR available<br />
to it. Recognizing the importance of the species, LHDA will implement a program<br />
to establish the Maloti minnow in other Lesotho rivers.<br />
Mohale Releases<br />
❏ Because of its more flexible release structures and mechanisms, Mohale Dam<br />
holds the greater potential for manipulating releases to meet river health targets<br />
in the Senqunyane River.<br />
❏ Because there is a considerable population living downstream of the Mohale<br />
Dam, important gains in water quality and maintaining riparian vegetation - an<br />
important resource - would result from even moderately increased flows. The<br />
Mohale impacts are predicted to reduce rapidly downstream due to inflows from<br />
tributaries.<br />
Compensation<br />
❏ The degree of uncertainty in predictions/ estimates of potential losses to<br />
communities means that monitoring of socio-economic status and biophysical<br />
status of riverine ecosystems will be of paramount importance in an adaptive<br />
management system.<br />
❏ The geographic extent of measurable impacts on the Population at Risk can be<br />
limited to river reaches represented by IFR Sites 1, 2, 3 and 7. This is the area to<br />
which, it is proposed, the IFR Policy’s compensation programs will apply. Monitoring<br />
will nonetheless extend to reaches 4, 5, 6 and 8 in order to confirm the moderate<br />
or negligable levels of impact predicted for these reaches.<br />
❏ Different principles of compensation and/or mitigation are required for downstream<br />
rivers (compared with upstream of the structures) because of the different nature<br />
of the impacts. The following principles are proposed:<br />
❏ Taking account of national socio-economic trends, communities will not be<br />
worse off after Policy implementation<br />
❏ Compensation will be based on resources affected or lost, not on resources used,<br />
and will generally be directed at communities, not at individuals;<br />
❏ Compensation will be for demonstrated losses, and both direct compensation<br />
(based on replacement of lost resources) and indirect compensation/ mitigation<br />
(other programs) will be considered.<br />
10