Although the Chinese government (who probably know their country best.) Say that Zipingpu dam had nothing to do with the massive earthquakes, I believe that it did, so much pressure from all that water had to do something to those tectonic plates.
When Hoover dam was built there were hundreds of earthquakes in the years afterward measuring up to magnitude 5--. there was no seismic history in that area. Another example of a dam causing earthquakes is Vanont Dam, built in 1960, 250 tremors were felt as it slowly filled, later when the reservoir was full, a large tremor knocked a huge slab of rock that slid into the reservoir causing a huge wave that swept over the dam killing 2,600 people. However Zipingpu earthquake has been the biggest dam earthquake ever. I believe that this can put down to it's place so close to fault lines. (Double click picture for a clearer view.) As you can see from the picture the Zipingpu dam is very close to several faults possibly multiplying the effects of the shock.
I wonder is there a way around this? Or will every time a dam is built will there be earthquakes? Maybe they shouldn't be allowed near faults or populated areas?
What ever the weather, I believe that Zipingpu Dam effectively killed 80,000 people.