Hundreds of soldiers and armed police on Monday are building an emergency channel to an overfilled reservoir that threatens to flood a northwest Chinese city with a population of 205,700.

Authorities said they expected to drain the Wenquan Reservoir near Golmud City, Qinghai Province as soon as early Tuesday. More than 9,000 residents in the city had been evacuated by Sunday.

Vice Governor Deng Bentai said if 50 million cubic meters of rocks can be supplied in time, the emergency channel could start working on Tuesday to discharge the excessive water.

Officials with the provincial disaster relief headquarters told Xinhua that the digging phase of the 250-meter-long channel -- 12 meters in width, 9 meters in depth -- has almost ended.

The channel together with two existing ones is expected to release 400 cubic meters of water per second, relieving the reservoir that is filled with 30 million cubic meters more that it can safely hold, officials said.

If it bursts, the reservoir could flood Golmud with waters in some places reaching up to 4 meters deep. The city's power and water plants are also at risk, the municipal government said earlier in a previous statement.

The Qinghai-Tibet Railway, the world's highest railway, could also be hit by flood waters as it is only 40 km away from the reservoir.

(Xinhua News Agency July 12, 2010)