INFORMATION DOCUMENT - DWA Home Page

This document is intended as a
means for sharing information
about the process adopted by the
Lesotho Highlands Development
Authority (LHDA) for developing
a policy for the release of water
into downstream river courses
(referred to as instream flow
requirements (IFR)) for the Phase
1 dams of the Lesotho Highlands
Water Project in Lesotho.
It also informs readers as to how
they may participate in the public
consultation process for the
development of the policy.
This document:
❏ Explains the context for and
need for an IFR policy
❏ Gives a brief introduction to the
theory behind IFR and the way in
which scientists go about instream
flow assessments (IFA) and
❏ Indicates where readers may
obtain further information and how
they may participate in the
process.
LESOTHO HIGHLANDS WATER PROJECT
Development of a Policy for Instream Flow Requirements
PURPOSE OF THIS
DOCUMENT
Senqunyane
INFORMATION DOCUMENT
Republic of South Africa
Republic of South Africa
Senqu
KINGDOM OF LESOTHO
Senqu
Malibamatso
MASERU
Mohale's Hoek
IFR 6 @ Seaka Bridge
IFR 7 @ Marakabei
IFR 8 @ u/s Senqu confluence
Quthing
Matsoku
Butha Butha
IFR 2 @ Katse
Thaba Tseka
IFR 1 @ Seshote
IFR 5 @ Whitehills
IFR 3 @ Paray
IFR 4 @ Sehonghong
Qacha's Nek
IFR Sites
IFR "Super Sites"
North
0 20 40
Kilometres
Republic of South Africa
KEY
LHWP Dams (extant and planned)
Border with RSA
The Lesotho Highlands Water Project (LHWP) was established by Treaty between
the Governments of Lesotho and South Africa in 1986. The purpose of this joint
undertaking was to transfer water from the highlands of Lesotho to the Vaal River
catchment, to augment water supplies to South Africa and to generate hydropower
for Lesotho.
The LHWP, one of the most ambitious water transfer schemes in the world,
was designed to be developed in four phases. If developed in full, the Project
would comprise 5 large dams in the upper catchments of the Orange River system,
with all the project infrastructure, except for part of the transfer tunnels and
discharge facilities, being located in Lesotho.
To date, the implementation of Phase 1 has been virtually completed. Phase
1A, comprising the largest of the dams, Katse on the Malibamats’o River, the
transfer tunnels to RSA, Muela tail pond and the Muela Hydropower Station, was
commissioned in 1998. Phase 1B is due for completion during 2003, with the
inundation of Mohale Dam scheduled to commence in October 2002. Phase 1B
consists of Mohale Dam on the Senqunyane River, Matsoku Weir on the Matsoku
River, and transfer tunnels from Mohale and Matsoku to Katse Dam.
The original demand predictions indicated that Phase 2 development would
follow immediately on completion of Phase 1. However, circumstances, including
a slower rate of growth in demand in South Africa, have conspired to result in the
certain delay of Phase 2. Thus, the process for developing a policy for the release
of water into downstream river courses (referred to as instream flow requirements
(IFR)) concerns only Phase 1.
Rivers
1

❏ Treaty commitments to
environmental management,
maintaining livelihoods and
compensating for losses
❏ The need for a scientific
approach to and policy for
managing releases and
downstream impacts
❏ Lesotho seeks to comply with
the Treaty and protect the interests
of its people
❏ South Africa seeks to comply
with the Treaty and South African
water law
❏ An IFR policy will ensure some
water is reserved for ecosystems
and communities downstream of
control structures
❏ The IFR policy will ensure that
reserved water is made available
to the ecosystem and communities
at appropriate times
❏ The IFR policy will outline
standards or indicators for the
management of the target river
health.
MOTIVATING
FACTORS
Why Do We Need an IFR Policy?
Water Releases: Design and Practice
When the LHWP was designed in the 1970s and 1980s, awareness of environmental
issues in general, and downstream environmental and social impacts of large dams
in particular, was much lower than it is today. Nevertheless, environmental issues
were embedded in the Treaty (see Box below) and the relevant Treaty articles were
given effect through the implementation of Environmental Action Plans (EAPs)
for both Phases 1A and 1B. The difference between 1A and 1B was that Phase 1B
environmental and socio-economic baseline studies were done in advance of
construction/implementation in the case of Mohale Dam, whereas the Phase 1A
baseline studies were being conducted while construction of the Project was already
underway. Thus, the Phase 1B EAP benefited from lessons learnt in implementing
Phase 1A.
The Phase 1 EAPs have, to date, applied only to the dam basins and upstream
catchment areas. It was the Phase 1B environmental impact assessment report in
1994 that identified the need for an instream flow assessment, to investigate
environmental and social impacts downstream of both dams and to design measures
to mitigate them or compensate for them.
As far as management of the downstream environment goes, operation of dam
releases under the Treaty articles (see box below) is the only operational mode
currently approved by Project authorities. The Treaty specified compensation flows
amounting to between 2% and 3% of Mean Annual Runoff (MAR). The Project
was designed and, for the most part, constructed, on the basis of the intended
transfer of approximately 93% of the water yield (MAR) from the rivers above
the LHWP structures. From 1996-2001, releases or flows from Katse were
substantially in excess of these parameters—averaging 32% of MAR, with a low
of 4,2% MAR in 1999 and a high of 61,6% MAR in 2001 (see box below).
Currently, to protect the river until an IFR Policy is in place, Katse Dam and
the Matsoku weir are being operated to release 750 litres per second (l/s) and 600
l/s, respectively.
Other than control of releases, to date no downstream management or mitigation
measures have been undertaken, except for the regular monitoring of water quality
in downstream rivers.
1996 64.0%
1997 30.5%
Katse Releases (% MAR)
1998 27.4%
1999 4.2%
LHWP TREATY ENVIRONMENTAL AND SOCIAL COMMITMENTS
2000 6.5%
2001 61.6%
Environmental considerations were incorporated into the Project from the beginning, notably as legally binding articles in
the Treaty. The main provision for environmental matters in the Treaty (embodied in Article 15) states:
“The Parties agree to take all reasonable measures to ensure that the implementation, operation and maintenance of
the Project are compatible with the protection of the existing quality of the environment and, in particular, shall pay due
regard to the maintenance of the welfare of persons and communities immediately affected by the project”.
Furthermore, Article 7(18) of the Treaty enjoins the Lesotho Highlands Development Authority (LHDA, the body set up
to implement the Project and be responsible for its operation and maintenance), to:
“effect all measures to ensure that members of the local communities in the Kingdom of Lesotho, who will be affected
by flooding, construction works or similar project-related causes, will be able to maintain a standard of living not inferior to
that obtaining at the time of first disturbance, provided that such Authority shall effect compensation for any loss to such
member as a result of such project-related causes not adequately met by such measures”.
The Treaty, in recognition of downstream needs, specified Phase 1 downstream flows (the “Treaty Minimum Releases”)
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.
2

PUBLIC DISCLOSURE
AND INVOLVEMENT
Public disclosure and input into
policy development is the policy
of the LHDA and a World Bank
requirement. It involves the use of
two-way communication:
❏ May-June 2002: a pilot
consultation process was
conducted, in 16 potentially
affected villages downstream of
Phase 1 structures in a 5 km wide
corridor each side of the river
❏ May-August: meetings with the
Principal Chiefs of Lesotho are an
important matter of protocol
❏ June-August: extension of this
process to all downstream villages
in potentially significantly affected
river reaches in a 5 km wide
corridor each side of the river (IFR
Sites 1, 2, 3 and 7)
❏ Public disclosure: this document
represents the first step in a
process which will inform the
broader interested and/or affected
community about the IFR policy
❏ Public consultation: the posting
of the Draft IFR Policy on websites
and in libraries, in early August
2002 for 30 days, for the purposes
of public comment
❏ Public notification: the posting
of the final IFR Policy and a
Response Report, to notify
stakeholders of the final Policy and
to explain how LHDA has
responded to concerns.
What is an Instream Flow
Requirements Policy?
Instream flow requirements (IFR) refer to the amount, quality and timing of water
released through or over dams and associated structures to meet riverine ecosystem
and social needs in the reaches downstream of dams. The objective is to mitigate
the impacts of such structures on the downstream environment and people.
Downstream affected people have to be consulted about the potential impacts of
the project on their livelihoods and compensated for any losses, in such a way as
to restore those livelihoods.
The approach adopted by LHDA, and endorsed by the Lesotho Highlands
Water Commission and the World Bank, was to focus on the obligations contained
in the Treaty and in the World Bank Loan Agreement to mitigate the adverse effects
of the dam on the downstream environment and people.
The IFR Policy will emphasize the establishment of a pattern of target water
releases—base flows and floods, in wet, average and dry years—that will ensure
that adverse impacts on the downstream environment do not exceed agreed levels
of river health conditions.
In contrast to the impact evaluations undertaken for areas upstream of the
LHWP dams, which typically dealt with largely significant impacts on a relatively
small number of people (a few hundred), downstream evaluation has had to deal
with relatively small impacts on a large number of people (tens of thousands) in
an area that had not previously been studied.
This approach - managing the river rather than managing the dam – makes the
ecological health of the river and the welfare of downstream communities key
elements in decisions regarding the allocation and use of water. It also paves the
way for establishing a firm basis for determining losses of and compensation for
downstream aquatic and riparian resources.
It will lead to an IFR policy that covers the geographic scope of the policy’s
interventions, a monthly release schedule that specifies base flows and flood
releases for wet, normal and dry years, dam operating procedures, monitoring, the
principles of the social mitigation and compensation process, record keeping,
audits, disclosure and consultation and the budget commitments required to operate
the policy.
Senqunyane River. (Photo: George van der Merwe)
3

It is important to note that, given the
scientific state of the art regarding
environmental flow requirement studies
and the forecasting of potential impacts,
the results of the studies should be
interpreted as providing guidance to
inform the formulation of a policy and
not as exact predictions of what may
happen.
Uncertain future rainfall patterns, the
specific way in which the river ecology
may respond to changed hydrological
and hydraulic conditions, and the
adaptation strategies of the downstream
riparian plants and animals, will all
interact to create a new ecology and,
potentially, new socio-economic
patterns.
This is why it is important to design a
policy that is adaptable to the emerging
reality on the ground and to monitor
the environmental and social conditions
as they evolve, in order to do the
maximum to ensure river health and the
livelihoods of the affected people.
The Outcome
The culmination of all these studies
will be the formulation and approval
by the Project Authorities of an IFR
Policy, which will
❏ commit the LHDA to a target
release regime from each of Phase
1’s dams, namely, Katse and Mohale
Dams and Matsoku Weir;
❏ commit the LHDA to specified
principles of mitigation of impacts
and compensation for losses;
❏ establish the basis for the
assessment of environmental and
social losses and procedures for
claiming compensation;
❏ set out the details of a monitoring
program which will support the
release regime, compensation and
mitigation policy; and
❏ establish a regular program to
review the policy in the light of the
results of the monitoring studies.
IFR STUDIES undertaken
by LHDA
Contracts 648 and 678
The decision to appoint a consultant to undertake a thorough assessment of
downstream impacts was taken during 1996. Metsi Consultants, a joint venture
of SMEC International of Australia and Southern Waters Ecological Research and
Consulting of South Africa, was contracted to undertake IFR studies of the Project
under LHDA.
Contract 648, conducted between 1997 and 2000, produced 22 separate reports.
The terms of reference for the study required consideration of the combined effects
of Phases 1 and 2. The study area included the Malibamats’o River downstream
of Katse, the Matsoku River (tributary of the Malibamats’o) downstream of Matsoku
Weir, the Senqunyane River downstream of Mohale, to their respective confluences
with the Senqu River, and the middle and lower reaches of the Senqu River, to the
border with South Africa. The study involved a wide range of specialists, from
physical and biological scientists to human and animal health and socio-economic
specialists.
When it became clear that a significant delay in the implementation of Phase
2 was probable, Metsi Consultants was asked to assess the situation without the
effects of Phase 2. This exercise was undertaken as LHDA Contract 678, the final
reports of which have recently been completed. These studies have analyzed the
downstream rivers’ responses to reduced flows and have predicted a range of
impacts, the overall trends of which are shown in boxes on succeeding pages.
Upstream of Katse Dam. (Photo: George van der Merwe)
4

Instream Flow Requirements: Theory and Practice
The analysis of environmental flow requirements is based on the premise that river flow is the primary determinant of a number
of physical and biological parameters in aquatic and riparian ecosystems. A crucial relationship exists between river flow or
discharge (analyzed as a number of components, notably base flows and floods), hydraulics and geomorphology. The volume
of flow determines the depth and size of the river and a number of ecological processes are linked to this.
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
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.
Furthermore, because the characteristics of a river change as one moves downstream, flow-ecology relationships change too.
One must, therefore, establish different relationships for each affected river reach. Thus, IFR studies focus their analyses on
carefully selected IFR Sites, representative of particular river reaches (the LHWP IFR Phase 1 Sites are shown in the map on
Page 1).
In Southern Africa, the Building Block Methodology (BBM) has been developed and used for the assessment of IFRs. The BBM
requires that a desired future state of the river be identified first; then the scientists
construct the seasonal flow regime, comprising base flows, small and large floods,
required to maintain that desired state. In the case of the LHWP, the in-stream
flow assessment (IFA) was needed to assist in determining a desired future state,
not the other way round, so a different approach was developed. This Downstream
Response to Imposed Flow Transformations (DRIFT) methodology allows the
biophysical and socio-economic consequences of flow changes to be determined
for a number of potential future flow regimes. That is, it is a scenario-based approach.
A Caveat. It is important to bear this in mind when reading the findings of these
studies, that the findings are based on a specific set of conditions defined as
the scenario and not on actual conditions. The findings are, thus, all predictions
and are only as good as the primary information or databases that support them.
For instance, the assessment of changes in riparian vegetation patterns requires
a detailed knowledge of the auto-ecology of individual species, but such data
are not available for the Highlands environment and species specifically, although
experience in other systems will be applicable to some extent. The results of
these studies must, therefore, be interpreted with caution; they must not be viewed
as fact, but rather as the best predictions currently available. Careful monitoring
of the system, after implementation of the IFR Policy, will be essential to establish
the actual system responses, to establish actual losses to resource users and to
permit adaptation as necessary.
The LHWP IFR analysis proceeded on the basis of eight IFR sites in the four rivers
of interest (see Map). Detailed, holistic field characterizations of each site field
were undertaken over a 12-month period to establish a baseline, although a preproject
baseline for the Malibamats’o River could not be established, due to the
presence of Katse Dam. The DRIFT methodology was then used to predict the
effects on different biophysical system components. Four modified flow regimes
were hypothesized, based on design and operational constraints and the nature of
the rivers. Finally, the consequences of the predicted biophysical changes on the
human Population at Risk were analyzed and the costs of potential resource losses
were calculated.
Bringing all the
elements together
The final phase of policy development
will be to assess the trade-offs between
river health, communities and the
implications of different release options
in terms of lost benefits to the two
countries – all within the context of the
Treaty requirement that the project
should “pay due regard to the
maintenance of the welfare of persons
and communities”, and “take all
reasonable measures to ensure…the
protection of the existing quality of the
environment”. If a purely financial
approach were to be taken, the project
would maximize revenue at the expense
of the downstream environment and
communities; if a purely environmental
approach were to be taken, the project
would release as much water as was
necessary to protect the environment
and communities at a high cost in terms
of lost revenue. The policy development
process seeks an intermediate position
that will represent a fair and reasonable
balance between the two extreme
positions.
5

YOUR INVOLVEMENT
Your involvement is very important
to us. While at this stage we seek
to inform, not to solicit comment,
we urge you to submit comments
on the Draft IFR Policy when it is
released.
Details about the venues where
documentation is available, and
where the Draft IFR Policy will
be posted are provided on the
next page.
WHO TO CONTACT
ABOUT THIS PROJECT
Should you wish to submit
comments, please do so to the
following email address
lhwp@lhda.org.ls
Or by fax to +266 325775,
for the attention of
Mr R Maphetla
Chief Executive Officer
LHDA
PO Box 7332
Maseru 100
Lesotho
Should you wish to discuss
anything relating to the IFR policy
process, or to obtain further
information, do not hesitate to
contact the following persons at
LHDA:
Ms. M. Mothepu
Deputy General Manager ESSG
Phone:
+266 835 0825
+266 85 0679 (Cell phone)
Mr. Taole Tesele
IFR Co-ordinator
Phone:
+266 835 0731
+266 85 2143 (Cell phone)
Description of the
Lesotho Highlands
Lesotho is a land-locked country 30 355km 2 in extent. The eastern two-thirds,
called the Highlands, are formed by the rugged Drakensberg and Maloti ranges,
which form a high, dissected plateau with an average elevation of about 2 500
metres above sea level (masl). The narrow river valleys are steep-sided; the
landscape is one of deeply incised valleys and peaks. The Senqu (Orange) River
drains the eastern and southern sectors and has several large tributaries, including
the Malibamats’o, Senqunyane and Matsoku rivers, which are the locations for
LHWP structures (see map).
Highland catchments are characterised by high rainfall, temperate summers
and long, cold winters, and they have high water yields due to rapid runoff from
the steep slopes. Rainfall occurs predominantly as thunderstorms of high intensity
and short duration. The nature of the rainfall and the rapid movement of water off
the steep slopes and thin soil results in a quick drainage reaction time. Highly
variable, but distinct wet, dry and transitional seasons are identifiable from
hydrological records. The wet/rainy season extends from December to March,
while the dry season usually extends from June through September.
Grasslands and shrublands dominate highland vegetation; wetlands occur in
all drainage lines. Vegetation zones along rivers typically have a higher biodiversity
than elsewhere and a higher proportion of woody vegetation, both indigenous and
exotic species. The wild animal communities of Lesotho are distinctive, with
several endemic species, but wildlife densities are very low due to heavy, uncontrolled
exploitation.
The human population along the rivers downstream of the LHWP structures
within Lesotho live in small villages, with a small proportion living in larger
settlements such as Marakabei. It has been estimated that some 8 300 households
in a 5km corridor on each side of the downstream rivers may be significantly
affected by Phase 1 of the LHWP. While foreign employment in South Africa
represents an important, although declining, source of income, rural people are
heavily dependent on local resources for their livelihood. Agriculture is an important
source of livelihood, but agricultural plots are constrained in size by topography
and soil depths. Relatively more and better land is available along the Matsoku
and upper Senqunyane Rivers than along the deeply incised Malibamats’o and
upper Senqu rivers. The nutrition status of local people, especially children, is low,
even by Lesotho rural standards, and there is a high incidence of childhood
infectious diseases as well as water-related diseases. Livestock are abundant in
the area (estimated populations of 68 000 catttle, 78 000 sheep, 131 000 goats and
24 000 horses and donkeys).
IFR Study Scenarios
Minimum Degradation Scenario
This scenario was developed as a hypothetical condition, in which maintenance
of the rivers in a state of minimal degradation from their current condition was the
main objective and only thereafter would water delivery needs be catered for (ie
transferred to SA). It assumed that 60-65% of Mean Annual Runoff would be
released to downstream ecosystems. This scenario allowed specialists to consider
interactively baseline conditions relative to flow levels and to establish the flows
below which significant ecological and physical changes could be anticipated. It
should be noted that this scenario is not technically achievable due to design
constraints on the structures
6

WHERE TO GET
MORE INFORMATION
The 3 key reports:
❏ Metsi Consultants (2002) Report
678-F-001, Summary of Main
Findings for Phase 1 Development
❏ Metsi Consultants (2002) Report
678-F-002, Additional Scenarios and
Production of a New Final Report
(Vol. II)
❏ S. Klasen (2002) The Costs and
Benefits of Changing Instream Flow
Requirements
are available on the following
websites:
❏ www.lhwp.org.ls.
❏ www.lesotho.gov.ls
❏ www.dwaf.gov.za
❏ www.sametsi.com
Hard copies of these reports are
lodged for public inspection at
the following venues:
❏ LHDA Library, 3rd Floor, Post
Office Building, Kingsway, Maseru,
Lesotho
❏ National Environmental
Secretariat Library, Post Office
Building, Maseru
❏ National University of Lesotho
Library, Roma, Lesotho
❏ DWAF Library, 3rd Floor Sedibeng
Bldg, Schoeman St, Pretoria
❏ World Bank office, Pro-Equity
Court, 1250 Pretorius Street,
Pretoria
❏ University of Cape Town Library,
Rondebosch, Cape Town
❏ Public Information Center, World
Bank, 1818 H Street NW,
Washington, DC
Should you wish to read further,
a full set of Metsi Consultants
Contract 648 reports are lodged
at:
❏ LHDA Library, 3rd Floor, Post
Office Building, Kingsway, Maseru,
Lesotho
❏ DWAF Library, 3rd Floor,
Sedibeng Bldg, Schoeman St,
Pretoria, South Africa
❏ National University of Lesotho
Library, Roma, Lesotho
Treaty Minimum Release Scenario
This is the scenario generated by application of the minimum release conditions
specified in the Treaty and is at the opposite end of the range from Minimum
Degradation in terms of water requirements. Conceptually, the scenario differs
from that above in that the volumes of delivery water are first specified and
consequential river conditions then assessed.
Design Limitation Scenario
This is a scenario based on the practical limitations of flow releases imposed by
the designs of the Phase 1 structures. In terms of volumes of water releases, it is
between the above two scenarios.
Fourth (Intermediate) Scenario
This scenario was selected to fall between the Treaty Minimum and Design
Limitation scenarios and to provide a reference point between the former (legally
defined and highest water delivery, but most severe environmental and socioeconomic
impacts) and the latter (possible within engineering constraints, but
likely to have high impacts on water and revenues).
Summary of Findings
Hydrological changes
The Table below gives a global picture of the hydrological changes that are predicted
to occur under each of the four scenarios. It is from the changes in the river
hydrology or flow regime that all other predicted changes are derived. This overview
presents the overall amount of water available to downstream ecosystems on an
annual basis, as a proportion of mean annual runoff (MAR), this being an estimate
of the average amount of water draining from the catchment in a year.
Table 1: Historical MAR, the annual volume allocated to the river and the percentage of
historical MAR that this represents, under each of the four scenarios at each IFR site for
LHWP Phase 1 development. Shaded sites represent reaches immediately downstream of
the dams in Phase 1a and 1b
IFR
Site
Historical
MAR
Minimum
Degradation
Scenario
MCM a -l MCM a -l %MAR MCM a -l %MAR MCM a -l %MAR MCM a -l %MAR
1 87 51 59 35 40 35 40 31 36
2 554 366 66 22 4 184 33 97 18
3 774 436 56 128 17 315 41 227 29
4 1572 866 55 831 53 831 53 831 53
5 1924 1194 62
6 3330 2171 65
Treaty
Minimum
Scenario
Design
Limitation
Scenario
Fourth
Scenario
Flows sufficient for Minimum Degradation
7 355 231 65 48 13 126 35 77 22
8 592 397 67 158 27 254 43 195 33
Site 1 = Matsoku R, immediately downstream of Matsoku Weir (30km)
Site 2 = Malibamats’o R, immediately downstream of Katse Dam (20km)
Site 7 = Senqunyane R immediately downstream of Mohale Dam (90km)
Site 3 = Malibamats’o R at Paray, downstream of confluence with Matsoku R (35km)
Site 4 = Senqu R at Sehonghong, representing Senqu between confluences of Malibamats’o and
Tsoelike rivers (125km)
Site 5 = Senqu R at Whitehills, between confluences of Tsoelike and Senqunyane rivers (85km)
Site 6 = Senqu R at Seaka Bridge, from confluence with Senqunyane to South African border (140km)
Site 8 = Senqunyane R upstream of the confluence with the Senqu R, from confluence with Lesobeng
R to the confluence with the Senqu R (40km).
7

PREDICTED IMPACTS
Vegetation (See also Resource Impacts)
❏ Narrower vegetation zones along
rivers
❏ Many riparian species will be less
abundant
❏ Algal blooms will be more frequent
❏ Some species will increase
Aquatic animals
❏ Increases in algal feeding invertebrate
community
❏ Increases in tolerant filter feeding
invertebrate communities; decreases in
sensitive species
❏ Increases in some Simulium,
(significant as stock disease vectors)
❏ Increases in midges
❏ Possible introduction of disease
carrying snails, Planorbidae and
Physidea
❏ Decline of some fish species: trout,
yellowfish
❏ Likely extinction of the Maloti
minnow in some river reaches
Resource impacts
❏ Decreases in shrubs and trees used
for fuel and construction
❏ Decrease in some medicinal plant
species
❏ Decrease in availability and size of
fish
❏ Decrease in availability of river sand
❏ Decreases in availability of wild
edible vegetation
❏ Increase in the availability of reeds
and thatching grass
Socio-economic impacts
❏ Immediately downstream of Katse
and Mohale dams, social impacts may
be critically severe under the Treaty
scenario, due to resource depletion
❏ Social impacts are low, however, for
all sites located two or more reaches
away from the structures
❏ The baseline health status of the
population at risk is relatively poor ;
the Treaty and Fourth scenarios increase
the risks of infection from moderate to
severe for diarrhoeal and skin and eye
diseases.
Summary of findings (continued)
The main significance of hydrological changes will be as follows:
Low flows will be lower, both wet and dry season low flows. Low flows are
important for creating different conditions in different seasons, dictating the
occurrence or emergence and population densities of various species at different
times of the year.
Small floods will be smaller and less frequent in occurrence. They stimulate
spawning in fish, flush out poor quality water, cleanse the riverbed and sort river
stones by size, thereby creating different habitats. They trigger and synchronize
activities as varied as upstream migrations of fish and germination of seedlings
on river banks.
Large floods will be almost eliminated, except for very wet periods when the dams
may overtop. Large floods provide scouring flows that shape the river channel;
they also trigger some of the same responses as small floods. They move and
cleanse cobbles and boulders on the riverbed and deposit silt, nutrients, eggs and
seeds on floodplains; they inundate backwaters, secondary channels and floodplains,
recharge soil moisture levels in the banks and trigger bursts of growth in many
species.
Flow variability will be reduced, in daily, seasonal and annual cycles. Variability
acts as a form of natural disturbance, which effectively creates temporal and spatial
habitat mosaics, of areas inundated and exposed for different periods of time. The
greater the habitat diversity, the greater the species diversity and the greater is
ecosystem stability and resilience against unnatural perturbations.
Overall Impact Rating
The overall significance of the potential biophysical changes flowing from these
hydrological changes was rated by Metsi for each IFR site, under each scenario,
as shown in Table 2.
Table 2: Reach-specific summary of the predicted combined biophysical consequences for
each scenario with Phase 1 dams in place. The levels of impacts are coded as follows:
white – negligible; green – low; yellow – moderate; blue – severe; red – critically severe.
1
2
7
3
4
5
6
8
Reach
Proximal to
dam or weir
Distant from
dam or weir
Minimum
Degrradation
M
M
L
L
L
N
N
N
Design
Limitation
** Site 1 is below Matsoku Weir, and attracts Severe and Critically Severe ratings, despite the relatively
high proportion of MAR (40%) still flowing down the river, due to the extinction in the Matsoku River
of the Maloti minnow. LHDA is establishing a program to protect the minnow in other Lesotho rivers.
Summary Findings
❏ Sites proximal to dam structures have the potential to be severely impacted
under all realistic scenarios (the exception is the Minimum Degradation scenario),
largely on the basis of physical in-stream habitat changes and losses of aquatic
biota.
❏ Consequential changes in riparian biota and resources are much less certain
(see Predicted Impacts), as are changes in human and animal health vectors and
agents.
S**
S
S
M
L
L
N
L
Fourth
S**
S
S
M
L
L
L
L
Treaty
S**
CS
S
S
M
L
L
M
8

RECORDED IMPACTS
Metsi Consultants did their baseline study
field work during 1999, when Katse Dam
was being operated at close to Treaty
minimum releases, so the results gave a
good indication of the kinds of conditions
which might prevail under the Treaty
scenario:
❏ The state of both the instream and
riparian habitat (“habitat integrity”) at site
2 (below Katse) was rated to be less than
50% (of the ‘pristine’ condition). Other
sites – not affected by a dam – got scores
of between 80% and 95%.
❏ Water quality at site 2 was poor, there
were abundant algae in the water
(mountain rivers usually flow clean) and
very few fish.
Monitoring downstream of Katse Dam
(IFR sites 2 and 3) in summer 2000/01
and summer 2001/02 has shown
❏ A reduction in instream river health
indicators at site 2, much less so at site 3,
largely due to the absence at site 2 of
sensitive groups of macro- invertebrates
(only tolerant groups were recorded)
❏ A lack of clear geomorphologic trends
(an important prediction of the IFR studies
was major changes in river
geomorphology), although sedimentation
in some pools was observed;
❏ Woody plant species have increased in
number and distribution, having colonised
boulder beds and sandbars, which would
previously have been often covered with
water. This appears to contradict the study
findings, but it does not mean that the
pattern will not change in the long term.
❏ During summer 2002, however, river
flow was very high and fish were reported
to be abundant below Katse Dam.
Metsi’s pilot community surveys,
conducted in April and May 2002, show
some communities already suffering fuel
wood shortages that are not due to the
project, that is, fuel wood resources are
already depleted in some areas.
They also report on the experience of
communities regarding both reduced flows
and flood conditions. Reduced flows allow
their stock to cross the river, where
previously they couldn’t, and encroach
into other villages’ grazing lands. High
flows, on the other hand, wash away trees
planted by individuals.
The Economics of IFRS
Losses To Downstream Communities
❏ The IFR study finds sizeable economic losses (in terms of use values and
necessary compensation costs) to downstream communities ranging from a total
of M2,9 million to M8 million annually depending on the IFR scenario chosen.
It should be kept in mind, however, that the figures are estimates only, based on
certain biophysical predictions, and are primarily for the purposes of scenario
comparison.
❏ The IFR study also finds that small increases in releases will only have a modest
impact on these losses, although there are differences between the various resources
and sites. Only considerable increases in IFR releases will succeed in sharply
reducing the losses to downstream communities. Even in the Minimum Degradation
Scenario, downstream communities do face losses for which, according to Treaty
rules, they should be entitled to compensation of some form.
❏ A recent pilot consultation process amongst downstream communities revealed
very realistic and clear preferences for mitigation and compensation amongst
potentially affected communities, from programs of assistance to replace lost
resources, to flow releases, to assistance with broader development needs as
mitigation for losses which would be difficult to replace directly.
Revenue and Other Losses
❏ While increasing IFR releases for Lesotho would reduce downstream losses,
Lesotho would also lose variable water royalties and hydropower revenues, which
would have a negative impact on Lesotho’s economy as a whole. For example, if
the Fourth Scenario were to be adopted, the loss to the Lesotho economy would
be some M17,5 million per annum at 1999 prices, or about 6% of the total revenues
from the LHWP. In addition the original objective that Muela HEP would make
Lesotho self sufficient in electricity, would be compromised.
❏ The Klasen study of the economic impacts of the different IFR release scenarios
shows that, from an economic point of view, the economic costs to Lesotho and
South Africa of increasing downstream releases beyond the Treaty minimum level
always outweigh the benefits for downstream communities (and, thus, the costs
of compensation for losses). This is the case from the point of view of the project,
of RSA and of Lesotho.
❏ In other words, the lost royalty and hydropower revenues would always be
greater than the economic losses to downstream communities.
❏ Notwithstanding this, the overall project benefits, over the life of this project,
are so large that the viability of the project is not affected by including these
downstream losses, that previously had not been considered in the economic
assessment of the project.
❏ While the water transfer benefits of the project would be sharply reduced under
the three scenarios with releases in excess of the Treaty Minimum, as would the
already low rate of return of the hydropower component, they remain sizeable
enough that LHWP as a whole remains viable even if IFR releases were increased.
❏ Therefore in setting the IFR policy some difficult decisions and trade-offs have
to be considered, and public consultation is an essential element in this process.
9

PROVISIONAL LIST
OF AUTHORITIES
AND IAPS
NATIONAL AUTHORITIES
❏ Government of Lesotho
❏ Ministry of Natural Resources
❏ National Environmental
Secretariat
❏ Ministry of Finance
❏ South Africa
❏ Department of Water Affairs &
Forestry
TRADITIONAL AUTHORITIES
❏ Principal Chiefs of Lesotho (24)
and their community development
representatives
AFFECTED COMMUNITIES
❏ Some 8,300 households in 338
villages in a 5-km wide corridor on
either side of the affected river
reaches, incorporating IFR Sites 1,
2, 3 and 7.
LENDERS/ DONORS
❏ World Bank
❏ European Investment Bank
❏ Development Bank of South Africa
OTHER INTERESTED PARTIES
❏ Lesotho Council of NGOs
❏ NGOs/civic organizations/
individuals in Lesotho and South
Africa
❏ International NGOs
Should you feel strongly that any
particular organizations should be
made aware of this project, please
do not hesitate to contact us and
give us their contact details (without
their contact details we will not be
able to involve them, due to the tight
program).
Implications for IFR Policy
Mitigation by flow releases: Overall
❏ The Minimum Degradation scenario was always a hypothetical option, since
design limitations in the dams prevent the releases being made which might achieve
it. It is not, therefore, an option that can be considered for operational purposes.
It has, however, been useful as a scenario against which to compare the other
scenarios.
Katse Releases
❏ The IFR studies show that the design limitations on Katse do not allow much
flexibility of release regime and that all three possible scenarios are predicted to
result in “Severe” overall ecological impacts in reaches immediately downstream
of the dam (Site 2).
❏ The Matsoku rating of “Severe” overall impact under all three scenarios is
heavily skewed by the probable extinction of one species from this river, namely
the Maloti minnow. If the Maloti minnow is taken out of the equation, then
Matsoku’s 600 l/s release regime will allow the downstream ecosystem to be
maintained in a reasonable condition, since it will have 40% of MAR available
to it. Recognizing the importance of the species, LHDA will implement a program
to establish the Maloti minnow in other Lesotho rivers.
Mohale Releases
❏ Because of its more flexible release structures and mechanisms, Mohale Dam
holds the greater potential for manipulating releases to meet river health targets
in the Senqunyane River.
❏ Because there is a considerable population living downstream of the Mohale
Dam, important gains in water quality and maintaining riparian vegetation - an
important resource - would result from even moderately increased flows. The
Mohale impacts are predicted to reduce rapidly downstream due to inflows from
tributaries.
Compensation
❏ The degree of uncertainty in predictions/ estimates of potential losses to
communities means that monitoring of socio-economic status and biophysical
status of riverine ecosystems will be of paramount importance in an adaptive
management system.
❏ The geographic extent of measurable impacts on the Population at Risk can be
limited to river reaches represented by IFR Sites 1, 2, 3 and 7. This is the area to
which, it is proposed, the IFR Policy’s compensation programs will apply. Monitoring
will nonetheless extend to reaches 4, 5, 6 and 8 in order to confirm the moderate
or negligable levels of impact predicted for these reaches.
❏ Different principles of compensation and/or mitigation are required for downstream
rivers (compared with upstream of the structures) because of the different nature
of the impacts. The following principles are proposed:
❏ Taking account of national socio-economic trends, communities will not be
worse off after Policy implementation
❏ Compensation will be based on resources affected or lost, not on resources used,
and will generally be directed at communities, not at individuals;
❏ Compensation will be for demonstrated losses, and both direct compensation
(based on replacement of lost resources) and indirect compensation/ mitigation
(other programs) will be considered.
10