article

The Lesotho Highlands Water Project (LHWP) is an ongoing water supply project with a small hydropower component, developed in partnership between the governments of Lesotho and South Africa. It comprises a system of several large dams and tunnels throughout Lesotho and South Africa. In Lesotho, it involves the rivers Malibamatso, Senqunyane and Senqu. In South Africa, it involves the Vaal River. It is Africa's largest water transfer scheme.

The purpose of the project is to provide Lesotho with a source of income in exchange for the provision of water to northern South Africa, as well as to generate hydroelectric power for Lesotho.

The potential benefits of the project were already identified in the 1950s by then British High Commissioner Sir Evelyn Baring, among others. After a complete feasibility study was conducted between August 1983 and August 1986 (German-British Lahmeyer MacDonald Consortium was appointed for this task), the project eventually began to realize.

The project has had an important impact on Lesotho's infrastructure, as several paved roads were built in order to improve access to the different construction sites. The project has been alleged to have had negative social and environmental effects. While compensation was paid to the few hundred households affected by the dam, it has not addressed the water supply problems of many people in Lesotho, except indirectly, by paying royalties to the Lesotho Government for development purposes. As a result, in recent years, Lesotho still suffered severe drought-related water shortages. Meanwhile, the supply of water was maintained to South Africa's main industrial areas where hundreds of thousands of Basotho now work and live.

Project features


Below is an overview of the main features of the first three phases of the project.

(installed capacity)
Phase IA Phase IB Phase II Phase III
Name Katse Dam Mohale Dam Mashai Dam Tsoelike Dam
Dam height (m) 155 153 182 155
Power generation* (MW) 110 N/A 166 N/A
Water transfer capacity* (m³/s) 16.9 10.1 28.0 8.6
Transfer tunnels Yes Yes Yes No

* The values are estimates based on the feasibility study, and may differ from the current or eventual values, respectively.

Phase I


Phase IA: Katse Dam

This phase of the project was completed 1998. It consisted mainly of the construction of:

  • The Katse dam, a rockfill dam, across the Malibamatso river.
  • A 48.2 km long transfer tunnel between the Katse reservoir and the Sentelina headpond, another reservoir in northern Lesotho.
  • A rockfill enbankment dam with central impermeable core at the Sentelina site.
  • A 110 MW hydropower plant at Tlhaka (also an enbankment dam with central impermeable core), North of Sentelina.
  • A delivery tunnel between Tlhaka and the Ash river, in South Africa.

Although the Katse dam has power generation capability, it serves mainly as the reservoir for the tunnel intake.

Phase IB: Mohale Dam

This phase of the project was completed 2002. It consisted mainly of the construction of:

  • The Mohale dam, a rockfill dam, located on the Senqunyane river.
  • A transfer tunnel between Mohale and the Katse reservoir.

The system is interconnected in such a way, that it is possible to transfer water to South Africa through the Katse reservoir.

Phase II: Mashai Dam


This phase has not been completed. It includes the construction of a dam and a pumping station on the Senqu river, at Mashai, that will provide the Katse reservoir with water (the Katse reservoir is located at a higher altitude than the Mashai dam) by means of a transfer tunnel. It will be the largest reservoir of the LHWP project.

In parallel, another system of tunnels will be constructed between Katse and Sentelina.

Phase III: Tsoelike Dam


This phase has not been completed. It includes the construction of another dam on the Senqu river, at Tsoelike. It will transfer water from Tsoelike to Mashai, by means of a pumping station and a tunnel system.

Phase IV: Ntoahae Dam


This phase has been completed. If completed, it will pump water from Ntoahae into the Tsoelike reservoir.

Lesotho Highlands Water Project | Dams in Lesotho

 

This article is licensed under the GNU Free Documentation License. It uses material from the "Lesotho Highlands Water Project".

Home Pageartsbusinesscomputersgameshealthhospitalshomekids & teensnewsphysiciansrecreationreferenceregionalscienceshoppingsocietysportsworld