All four units at the station suffered major damage, including generating equipment and outgoing lines. A team of experts led by Qiao Yong, Vice Minister of Water Resources, supervised repairs. Maintenance was carried out with support from Zipingpu Hydropower Development Company Limited, which owns the Zipingpu Water Control Project. As of May 17, three of the units were reconnected to the grid.
The Zipingpu Water Control Project is one of 10 key projects in the nation's West Development Program. The project comprises a 760-megawatt (MW) power station and a 156-meter-high concrete face rockfill dam with a total reservoir capacity of 1.126 billion cubic meters. The team of experts found that the dam was partially damaged by the quake but remains stable and safe overall.
For safety reasons, local authorities have decided to reduce the reservoir's water level as soon as possible. Resuming operation at the power station could improve the project's discharge capacity and ensure the dam's safety, as well as the power supply during ongoing rescue efforts.
According to the latest report from the State Electricity Regulatory Commission, 27 power plants were disconnected from the grid after the earthquake. As of May 18, seven power stations have resumed operation, and four have resumed power supply for plant service.
Most of the power plants that remain disconnected from the grid belong to the hydropower group in Maoxian County in northern Sichuan.