The Civil Engineering Contractor November 2018 | Page 29

Actual works have not yet started, but early drilling is under way. In 2005, a Phase II feasibility study was undertaken in two stages, aimed at identifying further development options and investigating the preferred option in detail, which culminated in the recommendation of the Polihali Dam and transfer tunnel for implementation. Procurement for consulting services is almost complete and advanced infrastructure construction is about to commence. Phase II includes the construction of a dam at Polihali and the Polihali to Katse transfer tunnel, with a significant investment into improving road infrastructure and associated environment and social programmes that will benefit the communities in the project area. “The LHWP is one of the largest ongoing development projects in the world. In 2006, the South African Institution of Civil Engineering (SAICE) named the LHWP as the Most Outstanding Engineering Achievement of the Century.” Phase II gearing up Tente Tente, Phase II divisional manager of the Lesotho Highlands Development Authority. says Tente. The first phase is already delivering approximately 25m 3 / second, and the second phase will add a further 15m 3 /second to total 40m 3 / second. There will be further phases to get to the final 70m 3 /second. Phase I of the project comprises the major water transfer and hydropower components involving the construction of a transfer tunnel from Mohale to the iconic 185m-high Katse Dam as the major intersection of the project. From Katse Dam there is a 45km transfer tunnel to a hydropower generation plant before the water exits Lesotho, through a delivery tunnel to the Ash River in South Africa as part of the Vaal River water system. Phase II proposes to add onto that with a new dam and tunnel, as well as a new hydropower scheme. INSIGHT Ian Massey, a civil engineer and founder of MDA Consulting. www.civilsonline.co.za CEC November 2018 | 27