Africa's biggest water project
17 March 2004
President Thabo Mbeki and King Letsie of Lesotho have inaugurated the latest phase of the Lesotho Highlands Water Project, which delivers water from the highlands of Lesotho to South Africa's Vaal River system and generates hydropower for Lesotho.
The project is Africa's largest ever water transfer project as well as the largest ongoing bi-national construction project on the continent.
The project aims to address the needs of South Africa's rapidly expanding Gauteng province, which generates almost 60% of the country's industrial output and 80% of its mining output, and where over 40% of South Africa's population live. The province needs more water than its main source, the Vaal River, can provide.
The Lesotho Highlands, with its high rainfall and surface area of high basalt mountains - the Maloti - is an outstanding catchment area.
The Lesotho Highlands Water Project captures most of the excess water from rainstorms in the Orange/Senqu River catchment and transfers it to the Vaal River system, at the same time ensuring the sustainability of life forms dependent on flows downstream of its storage dams.
Completion of the latest phase of the project - phase 1B - will solve Gauteng's water problem for the immediate future and rejuvenate the Vaal River. For Lesotho, it provides valuable income, job opportunities, electricity and infrastructure on which tourism and industrial development can thrive.
Construction on phase 1A of the project began in 1984, and the first dam, Katse, began delivering water in 1998.
Construction on phase 1B of the project began in 1998, and comprises the 145 metre high Mohale Dam on the Senqunyane River, the 32 kilometre Mohale Tunnel linking Mohale Dam to Katse Dam, and the 6 kilometre Matsoku weir and tunnel, which diverts flood water from the Matsoku River into the Katse reservoir.
Water transfer from Mohale Dam and the Matsoku River to Katse Dam has begun, and will gradually increase the volume of water delivered to South Africa from 20 to 26 cubic metres per second.
While Katse Dam is the highest concrete arch dam in Africa, Mohale Dam is the highest rockfill dam on the continent, consisting of 7.8 million cubic metres of rock that was placed and compacted before the addition of concrete face. The dam features a flexible outlet structure that ensures high quality water for downstream releases to ensure the sustainability of aquatic life.
Other infrastructure completed during phase 1B includes three mountain passes, 72 kilometres of tarred roads, 75 kilometres of power lines and over 100 construction houses. At the peak of construction, phase IB created more that 8 000 jobs for local and regional workers.
The entire project is expected to cost US$8-billion by the time of its completion in 2020.
Speaking at the ceremony at Mohale Dam on Tuesday, Mbeki described the Lesotho Highlands Water Project as a bi-national project to harness a natural resource, Lesotho's "white gold", for the benefit of both countries.
"For South Africa, the project brings improved security of water supply for both economic and domestic use, and will undoubtedly help to meet the increasing water demand for many years to come", Mbeki said.
"Equally, Lesotho enjoys the benefit of new infrastructure, including roads, expanded communication and electricity systems, health facilities, job opportunities, improved water supply and sanitation to numerous communities, and many additional secondary benefits associated with a huge capital investment with its revenue streams.
"The project not only sustains the development of both countries in significant ways, but provides a showpiece for the region and the rest of the continent of mutually beneficial co-operation."
In November 2003, the South African Institute of Civil Engineering named the Lesotho Highlands Water Project "project of the century" for its "immense impact on the betterment of the lives of South Africans and Basotho, the benefits it brought to the economies of both countries, the manner in which the environmental impacts were addressed, and the effective and efficient overall management of the project".