The Lesotho Highlands Development Authority (LHDA), consultants and contractors on the Polihali dam have marked an early construction milestone – the diversion of the Senqu river by the pre-cofferdam, and the subsequent diversion of the river into and through the diversion tunnels ahead of the construction of the cofferdam upstream of the Polihali dam wall. “This is quite an achievement to the engineering fraternity. It is a key moment of the construction programme because unless this happens, no other elements of dam construction can happen. It had to happen now because the timing of it during the winter season without rain was critical. If you miss it by a week or two, you may miss the entire window by another 12 months.
