According to reports, a dam near Thrangu (ཁྲ་འགུ་དགོན་ or "Changu" in Chinese media) monastery has been damaged. Many people, including nomads, had fled higher up into the mountains out of fear that the dam might collapse and the water in its reservoir will destroy the town of Jyekundo (སྐྱེ་རྒུ་མདོ) or Yushu (ཡུལ་ཤུལ / ཡུས་ཧྲུའུ).
This report from The Independent indicates that the dam is sitting like a time bomb that might cause another tragedy: "Emergency officials said the dam could burst at any time, putting 100,000 people in danger".
Thankfully it seems like the water in the reservoir of the dam has been drained and Jyekundo is safe for now.
Imagine what would have happened if the dam had bursted and its water swept the town of Yushu, minutes after the earthquake? Such concerns should be a wake up call for Chinese authorities to reconsider their dam building plans on the Tibetan Plateau, much of which is affected by seismic zones. See here, here and here for China's plans for hydropower development on the Tibetan Plateau.
Below are three Google Earth satellite images (click for larger view) of the dam and the town of Yushu. According to Google Earth, Yushu or Jyekundo is at an altitude of 3,685m and the upstream dam, located South, is at an altitude of 3,800m.