The Lesotho Highlands Water Project (LHWP) is a multi-phased project to provide water to the Gauteng region of South Africa and to generate hydro-electricity for Lesotho. It was established by the 1986 Treaty signed by the governments of the Kingdom of Lesotho and the Republic of South Africa. The project entails harnessing the waters of the Senqu/Orange River in the Lesotho highlands through the construction of a series of dams for the mutual benefit of the two countries.
Phase I of the LHWP, consisting of the Katse and Mohale dams, the ‘Muela hydropower station and associated tunnels was completed in 2003 and inaugurated in 2004. Phase II of the LHWP is currently in progress. It consists of two separate but related components: water transfer and hydropower generation.
The water transfer component of Phase II comprises an approximately 165m high Concrete Faced Rockfill Dam at Polihali downstream of the confluence of the Khubelu and Senqu (Orange) Rivers and an approximately 38km long concrete-lined gravity tunnel connecting the Polihali reservoir to the Katse reservoir. Other Phase II activities include advance infrastructure (roads, accommodation, power lines and telecommunication, etc.) and the implementation of environmental and social mitigating measures.
The hydropower component of Phase II, which is currently under further feasibility studies, may include a pumped storage scheme, conventional hydropower such as the expansion of the ‘Muela infrastructure or new greenfield sites. Its exact form will be determined on completion of the further feasibility studies.
Phase II is expected to be substantially complete by the end of 2024.