Thousands of tons of garbage washed down by recent torrential rain are threatening to jam the locks of China's massive Three Gorges Dam, and is in places so thick people can stand on it, state media said on Monday.
Chen Lei, a senior official at the China Three Gorges Corporation, told the China Daily that more than 3,000 tons of trash was being collected at the dam every day, but there was still not enough manpower to clean it all up.
"The large amount of waste in the dam area could jam the miter gate of the Three Gorges Dam," Chen said, referring to the gates of the locks which allow shipping to pass through the Yangtze River.
The river is a crucial commercial artery for the upstream city of Chongqing and other areas in China's less-developed western interior provinces.
Pictures showed a huge swathe of the waters by the dam crammed full of debris, with cranes brought in to fish out a tangled mess, including shoes, bottles, branches and Styrofoam.
Some more than half a million square feet had been covered by trash washed down since the start of the rainy season in July, the report said. The trash is around two feet deep, and in some parts so compacted people can walk on it, the Hubei Daily added.
"Such a large amount of debris could damage the propellers and bottoms of passing boats," Chen said. "The decaying garbage could also harm the scenery and the water quality."
The Three Gorges Dam is the world's largest hydropower project, and was built partly to tame flooding along the Yangtze, which killed over 4,000 people in 1998 and countless more over the centuries.
Enormously expensive and disruptive, the dam has cost over 254 billion yuan ($37.5 billion) and forced the relocation of 1.3 million people to make way for the reservoir. Towns, fields and historical and archaeological sites have been submerged.
Environmentalists have warned for years that the reservoir could turn into a cesspool of raw sewage and industrial chemicals backing onto nearby Chongqing city, and feared that silt trapped behind the dam could cause erosion downstream.
China has made scant progress on schemes drawn up nearly a decade ago to limit pollution in and around the reservoir.
Chen said about 10 million yuan ($1.5 million) is spent each year clearing floating waste by the dam.