Torrential rains triggered two landslides in the Yuanmou County in northern Yunnan yesterday.
A quake lake was formed along the Longchuan River in the upper reaches of the Jinsha River, state-run Xinhua news agency reported.
Roughly 1.26 million cubic metres of debris moved down the mountains nearby, forming a six-metre-deep lake, measuring 700 metres long and 300 metres wide.
The lake put the lives of more than 8,000 people living downstream in danger, Chuxiong prefecture government said in a statement.
The residents were relocated yesterday.
Repairs are currently underway.