Dam 20 km from epicenter

When I was just examining the area around the epicenter of the Sichuan earthquake, I discovered a dam very close to it (about 20 km) which is about 600 m wide and located next to D?ji?ngyàn (???). Interestingly it only appears if you zoom in, so it seems that it has been built recently or some of the image data is very old. I wonder how it can have survived that earthquake, if they even worry about the 760 km distant Three Gorges Dam. If it broke, this would be an additional disaster for the people there, but it is completely uncovered by media so far.

Update: The dam is the Zipingpu dam (???). According to reports it has severe cracks now and is not operational anymore.

(Click on the pictures for the original maps)