Chinese media say lock gates at the Three Gorges Dam are in danger of being jammed by massive amounts of garbage that have washed downstream during weeks of severe rain.
An official told the China Daily that workers clear 3,000 tons of trash from the reservoir every day, but cannot keep up with the flow. The Hubei Daily said the floating debris is so thick that a person can walk on it.
The locks allow vital shipping to reach more than 150 million people who live upstream on the Yangtze River. Residents routinely throw trash into the river, but the volume is heavier than usual after two months of heavy rain and floods that have killed almost 1,000 people across China.
In Henan province, rescuers have now recovered 51 bodies from the Yi river, where a crowded bridge collapsed more than a week ago. Fifteen people are still missing.
About 300,000 people have been without drinking water for two days (in the city of Tonghua) in Jilin province, where flooding damaged four major water pipelines.
The mass of refuse at Three Gorges covers some 50,000 square meters and is reported to include shoes, bottles, branches and styrofoam. An official told Hubei Daily the trash also posed a threat to the quality of the water and to passing boats
The Chinese government pushed the construction of the dam in the 1990s, citing its capacity for massive clean energy generation and flood control. But opponents said the project would hurt the environment and cause suffering to more than a million people who had to be moved for the construction.
Some information for this report was provided by AFP, AP and Reuters