The Katse Dam, a concrete arch dam on the Malibamat'so River in Lesotho, is Africa's second largest double-curvature arch dam. (The Tekezé Dam, completed in early 2009, is now Africa's largest double curvature dam). The dam is part of the Lesotho Highlands Water Project, which will eventually include five large dams in remote rural areas. The dam is just below the confluence of the Bokong River, which forms the western arm of the Katse reservoir. The potential of the project was identified by the South African civil engineer Ninham Shand in 1953 as a possible means to supplement the water supply of South Africa's industrial heartland in the Witwatersrand. The World Bank arranged a treaty between the governments of South Africa and Lesotho, allowing the project to proceed. Construction The dam was built by a consortium of Bouygues, Concor, Group 5, Hochtief, Impregilo, Kier Group and Sterling International. The dam was completed in 1996 and the reservoir filled with water by 1997. The total cost of the project was US$8 billion. Katse Airport was constructed southeast of the dam to facilitate access to the project. Environmental impact The mass of water gave rise to induced seismicity. Farmers who lost land to the project have had trouble re-establishing new livelihoods. There is little arable land in the mountains to replace all that was lost, and efforts to help them with new livelihoods have by no means been as successful as the engineering works. A local group has documented the project's human legacy in the rural communities directly affected by the project, and the environmental and human-rights NPO, International Rivers, produced a detailed account of the effects. As mitigation of the loss of habitat, plant rescue missions were conducted in the area to be flooded, and Katse Botanical Gardens was established to house and propagate the plants rescued. Water delivery Water from the dam first travels through a , diameter tunnel, exiting at a hydroelectric station near Muela. The dam's high elevation allows a gravity flow water delivery system to South Africa, in addition to hydroelectric power for Lesotho, and was a prime reason behind the choice of site. Water delivery officially began on 22 January 1998. The dam currently supplies about of water to South Africa, which pays Lesotho $35 million per year, plus a variable royalty based on calculated water usage benefits. In recent years, water from the scheme has