Overview of the Lesotho Highlands Water Project (LHWP) <<..back [continuation]
The bi-national, Lesotho Highlands Water Project (LHWP), between the Kingdom of Lesotho (KOL) and the Republic of South Africa (RSA), is one of the most comprehensive engineering projects of its kind in the world, aimed at harnessing the water resources of the highlands of Lesotho to the mutual advantage of South Africa and Lesotho. The whole concept of the LHWP can be traced as far back as around the 1930s§, in which the idea of capturing the Lesotho high summer rainfalls by dams and transferring to parts of RSA, enthused South Africa.
The initial survey of the water potential of Lesotho was first introduced by the then British High Commissioner to Lesotho Sir Evelyn Baring around the 1950s. Ninham Shand of South Africa was appointed as consulting engineer to study the potential of harnessing the water of the Maluti Mountains for economic benefit of the Basotho people.
Joint Preliminary Feasibility Study
A joint preliminary feasibility study of the project with each government appointing its own consultants to assist in the study was carried out in 1978. A preliminary Feasibility report (Olivier, Binnie, 1979) concluded that a constant flow of some 35m³/s could be transferred to South Africa using a phased construction of five reservoirs at Oxbow, Pelaneng, Soai, Polihali and Taung on the Malibamats'o and Senqu (Orange) rivers and approximately 102km of tunnel to transfer water to South Africa. The generation of hydroelectric power in Lesotho was an integral part of the project proposal.
Joint Detailed Feasibility Study
The detailed feasibility studies to suit the requirements of the two governments were carried out from August 1983 to December 1985 by Lahmeyer MacDonald Consortium (comprising Lahmeyer International of Germany and Sir Malcolm Macdonald of U.K.) for GOL and Olivier Shand Consortium (comprising Henry Olivier and Ninham Shand Inc.) for RSA. The government of Lesotho's interests were looked after by the LHWP Unit (LHDA's and JPTC-GOL's predecessor) who were assisted by TAMS Pty. (Ltd.) of the U.S.A. in the technical review field. The LHWP unit and TAMS together formed the Study Supervisor for GOL on the Feasibility Study from 1983 to 1986.
The main objectives of the feasibility study were: -
Detailed reports issued under the detailed feasibility studies were in volumes as follows:
The Feasibility study established the economic viability of the project to deliver about 70m³/s of water from the highlands of Lesotho to the Vaal River system by the year 2020. The project was to be developed in a number of phases and the project was found to be the cheapest option compared to other competing schemes in RSA.
Hydroelectric power was to be generated in Lesotho, which offered Lesotho the opportunity for a substantial element of independence in electricity supplies.
The study confirmed that there were no technical, social, environmental, legal, economic or financial considerations, which would invalidate the conclusions that the recommended project would provide considerable benefits for both countries.
The recommended feasibility study Phase 1A project components were as follows:
An independent 3-member international panel of engineering experts was engaged by Lesotho from January 1984 to February 1986 to review the Feasibility Study work. During this period, the panel made three visits to Lesotho and to the project sites.
The signing of the Lesotho Highlands Water Project Treaty by the Government of Lesotho and of the Republic of South Africa on the 24th October 1986 established the Joint Permanent Technical Commission (JPTC) to represent the two countries in the implementation and operation of the LHWP. This was followed by detailed Engineering studies and services prior to the award of main works, which were scheduled to commence in early 1990. The treaty commits RSA and Lesotho to implementation of Phase 1A and 1B of the project and provides the options for development of additional phases in the future.
The first Phase (1A) of the proposed four phased scheme, comprising a giant dam, at Katse in the central Maluti mountains, 82km transfer and delivery tunnel system reaching to the Ash River across the border in R.S.A, 'Muela hydropower station and associated structures have now been completed. This phase was commissioned in 1998 and an average 17m3/sec of water is now being delivered to R.S.A.
Phase 1B, comprising; Mohale dam, a 145 metres high concrete faced rockfill dam on the Senqunyane river some 40km south-west of Katse; a 32 km long transfer tunnel between Mohale and Katse reservoirs, a 19m high concrete diversion weir on the Matsoku river and a 5.6km long tunnel, are under construction. The Mohale reservoir and Matsoku diversion will add 9.5 and 2.2 m3/sec to the yield of Katse. Completion of these components is scheduled for 2003/4.
The feasibility study layout envisioned the following:
Completion of all four phases would provide the 70 cumecs foreseen at feasibility study stage.
The Treaty provides for negotiations to be held between Lesotho and RSA before further phases of the LHWP can be implemented Such negotiations are on-going ,but it is now accepted that there will be a delay before phase 2 can be undertaken.
§ New civil engineer 14th Sept. 1995, pp. 20 - 29