The state-run Xinhua News Agency gave no immediate details on the survivor, found nearly four days after the disaster struck. Earlier Wednesday, a 50-year-old man was rescued who had been trapped in knee-deep mud on the second floor of a hotel, Xinhua said.
Local officials were cited as saying at least 627 people were still missing.
The National Meteorological Center warned there was a "relatively large" chance of more landslides in the coming days, as heavier rain was expected, with up to 3 1/2 inches (90 millimeters) forecast for Friday.
Troops and rescue teams, joined by traumatized survivors, were increasingly turning to recovering bodies and seeing to the needs of the living. Clean drinking water was a primary concern, with most local sources destroyed or too polluted to use.
Entire communities in Gansu province's Zhouqu district were swallowed when the debris-choked Bailong River jumped its banks early Sunday, releasing wave after wave of mud and rubble-strewn water. While torrential rains were the direct cause, tree cutting that left the dry hills exposed and the weakening of cliff faces by a massive 2008 earthquake were seen as contributing factors.
Buildings were torn from their foundations, their lower floors blown out by the force of the debris-laden water. Three villages comprising hundreds of households were entirely buried and much of the county seat was submerged.
"In some households, all the people have died," making the counting of the dead more difficult, Zhang Weixing, a Ministry of Civil Affairs official, told a news conference Wednesday.
Crews using explosives and excavators rushed to drain an unstable lake on the Bailong upriver of Zhouqu, fearing more rain could cause a massive breach, bringing more misery to the town.
"The danger of the barrier lake collapsing has been basically eliminated," Jiao Yong, deputy vice minister of the Ministry of Water Resources, told the news conference.
Disinfectant crews in protective suits sprayed chemicals across the ground and over machinery, the smell of death heavy in the air. State media reported numerous cases of dysentery, while infected injuries, a lack of sanitation, clean drinking water and accumulating garbage increased the risk of typhoid, cholera and other diseases.
By DAVID WIVELL, Associated Press
