I have no idea where the dam is located relative to this event. 7.8 is not enough to seriously affect the dam anyway. It would take something near to 9.0 to bounce that significantly.
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http://wwitv.com/tv_channels/b3686.htm
I don't speak Chinese but they do seem to have earthquake coverage. Mostly interviews with people standing outside.
The coverage seems to be heavily censored. The only damage pictures always have swarms of unsoiled smiling Chinese paramilitary types standing around.