The upstream cofferdam at China’s Heihe water control project has been filled to el 527, and can now retain water with a 20-year flood frequency and a flow of 2200m3/sec. Filling of the cofferdam was completed around ten weeks ahead of schedule.
Work at the Heihe site is being carried out by China’s Shaanxi Hydroelectric Con-struction Bureau. Between successfully closing the Heihe river in October 1998 and filling the cofferdam, some 0.96M m3 of rock material had been placed on the dam. In addition, 0.106M m3of sandy gravel had been placed on the foundation.