(Xinhua)
Updated: 2007-10-12 18:56

CHENGDU -- Three thousand people have returned to their homes a week after they were threatened with inundation by a mud-rock flow that blocked a river in southwest China.

Their return was made possible after emergency workers blasted the top off a dam formed by the flow and dug a channel to allow the potential floodwaters to drain.

The dam formed at 8:00 am on October 5 when an estimated 500,000 cubic meters of mud and rock swept down a 150-meter hill in Qingchuan County, Guangyuan City, Sichuan Province, and blocked a river.

Within hours, about 13 million cubic meters of water had accumulated behind a 30-meter-high dam, creating a lake 16 meters deep.

The dam, about 150 meters long and 150 meters wide, was in danger of collapsing and unleashing waves more than 10 meters high that could have submerged four square kilometers, said Wang Jianbo, a local Party official.

The disaster threatened those living in villages near the dam. More than 2,800 mu (187 ha) of crop lands were submerged. Traffic, electricity and telecommunications were cut off.

To ensure the safety of the villages, officials decided on a controlled demolition to drain the water, Wang said.

On Thursday, emergency workers dug a 15-meter-wide channel after blasting the top of the dam. After 24 hours of draining, the water level had dropped to 2.1 meters, removing the danger of flooding.