A county seat with more than 100,000 residents has stopped drawing water from its original Fujiang River source with the arrival of the runoff from China's main Tangjiashan "quake lake."

Tongliang County in Chongqing municipality had instead resorted to two standby reservoirs. They contained more than 20 million cubic meters of water and could ensure supply for three months, said Zhao Wuqiang, a local government publicity official.

The runoff from Tangjiashan, packing mud, sand and flotsam, arrived at the county at 11:30 PM on Wednesday and raised the water level in the Fujiang River by two meters. It proved difficult for the local water plant to purify. The pollution was not serious, Zhao added.

He said Tongliang officials would keep a close eye on the water quality and would resume drawing supply if the river came back to its original state.

Previously, waterworks in Mianyang City had suspended intake from the Fujiang since Tuesday night as the local water quality monitoring center found it was contaminated by the outflow.

The supply for more than 500,000 people in Mianyang's urban areas now comes from underground reserves. The local government was ensuring 50 liters of drinking water daily per person.

The Tangjiashan quake lake was formed after quake-triggered landslides from Tangjiashan Mountain blocked the Tongkou River running through Beichuan County, one of the worst-hit areas in the May 12 quake. It began to drain on Saturday morning through a manmade spillway.

Authorities called off an alert on the lake on Wednesday afternoon, a day after Sichuan's Communist Party head Liu Qibao declared "a decisive victory" in the drainage efforts.

(Xinhua News Agency June 12, 2008)