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The Groot Letaba River Water Development Project (GLeWaP) is a
major initiative by the DWS in
support of the Limpopo Provincial
Government’s development strategy.
The project will have a positive impact on
the regional economics and on
eradicating poverty, this will mainly be
achieved through:
- Increasing the safe, reliable water
supplies for domestic and industrial use;
- Minimizing the frequency, intensity
and duration of restriction on the use
of water allocated for irrigation of high
value crops;
- An increase in total household income
through stabilising the job market;
- Providing leverage for the equitable
distribution of resources.
The proposed infrastructure will make it
possible to improve the anagement of
water resources so as to stop degradation
of the conservation status of the riverine
ecosystem.
The GLeWaP includes a number of
infrastructure components, as well as a range of other initiatives.
 Non-infrastructure options
The Department is pursuing the following
non-infrastructure options to make more
water available:
 Water conservation and demand
management, as well as water recycling and re-use
The aim is to ensure that increased
efficiency and effectiveness of water use
will help address some of the short- and
long-term water requirements of the area.
Local groundwater resources
During the feasibility studies in the 1990s
and from recent investigations, it was
found that although groundwater cannot
be considered as the only source of water
to satisfy increasing needs, it can be used
to good effect for small-scale domestic
water supplies and food plot irrigation. In
this area with limited water resources the
conjunctive use of ground and surface
water should be promoted. Groundwater
resources should be developed
incrementally to increase yields, but with
ongoing monitoring to ensure good water
quality. The Department will make recommendations to local authorities in
this regard.
Removal of invading alien
vegetation
DWS’s Working for Water Programme is
actively removing invasive alien
vegetation in the Groot Letaba Valley as a
means of improving the yield in the river
system.
Regional economic assessment
This assessment would consider the
developmental impact that construction of
the project infrastructure and making
additional water available will have on the
economy of the region and of the national
Gross Domestic Product (GDP), and to
which sectors water would best be
allocated. It will also evaluate potential
benefits to Mozambique as a spin-off from
the economic development plans for the
project area.
Irrigation efficiencies
Irrigators in the river system, and
particularly those reliant on Tzaneen
Dam, are regularly subject to restrictions
on the water available. Allocations are
currently set at 50% of the annual quota
as a result of the current drought
conditions and low levels of water in
storage. This has a significant impact on
fruit production and on the socio-economy
of the region. The irrigation sector
already relies on modern technology and
has invested heavily in management and
sophisticated equipment to improve water
use efficiency.
Reserve determination
In accordance with the National Water
Act (NWA) [PDF - 240KB], the Reserve is that portion of water
required to meet basic human needs, and
the needs of the aquatic ecosystem. The
DWS undertook a Preliminary Reserve
Determination for the Groot Letaba River
in 2006, and the resulting requirements
will be taken into account in both the yield
analysis and technical design of the
project.
Institutional arrangements
It is foreseen that the DWS will be the
owner of the water resource components
of the project. This will be revisited as and
when new institutions such as the
proposed National Water Resource
Infrastructure Agency and the Catchment
Management Agency have been established. After completion, a regional
water supply entity would be considered
for the management of the new bulk
distribution infrastructure. Any potable water supply systems that will be served
by the bulk distribution system will be the
responsibility of the relevant municipalities.
A high-level Project Steering Committee
has been established by the DWS, and
includes the Limpopo Provincial
Government, Mopani District Municipality,
local municipalities, traditional authorities,
sectors such as conservation, agriculture
and industry to steer the post feasibility
bridging studies.
Cooperative governance
Investigating and implementing such a
major infrastructure project to improve
water management in the area is likely to
give rise to many development
opportunities, lead to change in socioeconomic
circumstances, cause changes
in land use and have other beneficial
effects.
Numerous other government authorities
thus need to be consulted and participate
so to accommodate these proposed
developments in their planning and future
activities. This includes the local
authorities who will be required to include
these proposals in their Integrated
Development Plans (IDPs) in order to
ensure access to potable water for their
communities.
Together with the DWS, they will assist
in ensuring that all the projects and
developments resulting from this initiative
are sustainable, and that as many people
as possible benefit from infrastructure
development now being investigated.
International liaison
The DWS will continue to liaise with the
country’s neighbours during the planning
and implementation of the GLeWaP in
line with international protocols and
agreements.
Dam at Nwamitwa site
The main component of the proposed
project comprises a new major storage
dam at a site in the Groot Letaba River
referred to as the Nwamitwa site,
downstream of the confluence of the
Nwanedzi River. The proposed dam wall could be 36m high and comprise a
concrete structure in the river section
accommodating a spillway and outlet
works, with earth embankments on both
flanks. With a storage capacity of 144
million m³ it would increase the system
yield by about 47 million m³ per year. (By
comparison, the capacity of Tzaneen
Dam is 157,5 million m³).
The final size of the dam will be
determined in a series of technical and
financial investigations, informed by the
findings of the EIA. The dam will be
designed to enable the requirements of
the Reserve in the Groot Letaba River,
particularly in the river reach downstream
of the dam.
The R529 and other important roads in
the area will have to be re-aligned to
accommodate the dam. Local alignments
will be determined in consultation with
landowners and the provincial road
authorities and will take cognisance of the
impacts investigated during the EIA.
Raising of the Tzaneen Dam wall
It was also proposed to increase the
capacity of Tzaneen Dam to
approximately 203 million m³ by raising
the dam wall. This could increase the firm
yield of the dam by about 6% from 60
million m³/a to 64 million m³/a, but more
importantly, the dam could then be
operated so as to minimize the frequency
and intensity of restrictions on water
allocations for the irrigation of permanent
fruit orchards.
Other infrastructure
Bulk water supply infrastructure including
pipelines, a water treatment plant, various
pump stations and reservoirs will be
investigated.
The various reservoirs will be located so
that local authorities will be able to obtain
water for reticulation to individual users.
All infrastructure will be fenced off with
security fencing. Final sizing is still to be
completed but pump stations and
reservoirs could each occupy an area of
about half a football field.
Electricity requirements for the project will
be assessed separately by Eskom.
Construction
Construction activities will take
approximately five years, with several
construction teams working concurrently
in different areas at the proposed dam
site and along the pipeline routes.
Residential accommodation for
construction staff will be established in the
vicinity of the proposed dam or in
established towns. Housing, internal
roads, water and electricity supply, waste
water treatment, solid waste disposal,
emergency facilities and recreational
amenities will be provided.
Funding of the GLeWaP
The construction cost of the infrastructure
components of the project is estimated to
be in excess of R1 500 million. Funding
sources are likely to include a private
sector and a public sector component
funded by the National Treasury.
Construction sites will include offices,
internal roads, water and electricity
supply, waste water treatment, solid
waste disposal, emergency facilities,
areas for the handling of hazardous
substances, workshops, washbays, areas
for the safe storage of explosives, and
communication infrastructure.
The sites will also include facilities for the
bulk storage and dispensing of fuel for
construction vehicles and working areas
for stockpiling construction materials and
concrete batching and bitumen plants.
Running concurrently with the EIA
investigations is the process to obtain
authorisation from the Department of
Minerals and Energy (DME), in terms of
the Minerals and Petroleum Resources
Development Act (Act 28 of 2002), to use various quarry
and borrow pits to provide gravel and
sand for construction.
Location of the borrow pits will be
determined during the study and local
landowners are invited to contribute
information about the occurrence of
material suitable for this purpose.
Scheduling
The target is to commence with the
supply of water from the new dam by
2012, with full yield by around 2013,
should environmental authorisation be
obtained. For this to be achieved
construction of some of the infrastructure
must start in late 2009. The
possibility of starting to abstract water
from the dam during the filling period
is also being considered.
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