UPDATE 2-China warns of threat from dams weakened by quake

(Adds Huaneng warning in paragraphs 4-5)

By Chris Buckley

BEIJING, May 15 (Reuters) - The earthquake that devastated southwest China has left many dams badly damaged, posing an unknown threat of collapse and flooding made worse by poor management and information, the country's water minister said.

In Sichuan and Chongqing, at least 17 reservoirs have been damaged, with some dams cracked or leaking water since the quake struck on Monday, according to state media. Several are on the Min River, which tumbles through the worst-hit areas between the Tibetan plateau and the Sichuan plain.

Chinese state media said troops rushed to repair cracks in the Zipingpu Dam in Sichuan province caused by the earthquake on Monday. The dam is now deemed structurally stable.

An official from Huaneng Power Group told state television on Thursday that contact had finally been made with 110 people trapped at the Taipingyi hydropower plant near the badly damaged city of Yingxiu, but would have to evacuate them by air.

"The big problem is the dam faces a danger of collapsing and the water level has kept rising," Zhang Ping told CCTV.

Water Resources Minister Chen Lei said such damage was widespread and sounded far from assured in comments put on the ministry Web site (www.mwr.gov.cn) on Thursday.

"Especially in Sichuan province, there are many dams, damage from the quake is extensive and the hazards are unclear," Chen said in a speech to officials a day earlier.