Millions of tons of garbage and industrial waste could seriously affect the water quality and operation of the Three Gorges dam project in China if clean-up measures are not taken immediately, a Chinese environmental official has warned.

   The world's biggest dam, which is under construction in the upper reaches of the Yangtze River, is scheduled to be ready for water storage in 2003. Garbage and waste left untreated along the river will be submerged if not cleaned away.

   "If the rubbish is left inside the reservoir, the pollution could become worse and normal operation of the hydropower station will be affected," said Liu Qifeng with the State Environmental Protection Administration (SEPA).

   But the central government has decided to prevent this from happening, he told a press conference here Thursday.

   The State Council, China's cabinet, has approved a ten-year plan focusing on water pollution control in the dam area and the upper reaches of the Yangtze.

   By investing about 40 billion yuan (4.8 billion U.S. dollars), the central government will help five provinces build water and garbage treatment facilities, upgrade the pollution control facilities of factories, and improve the environment.

   By 2010, there will be 146 waste water disposal centers and 161 garbage treatment plants in cities and towns around the reservoir, Liu said.

   Paper mills, fertilizer plants, wine breweries, mines and other heavy-polluters will be closed if they fail to meet the  pollutant  emission standards set by the state, he said.

   Fearing soil erosion may cause severe silting in the reservoir, environmental protection authorities have urged local people to plant trees on slope farmland which is vulnerable to erosion due to the lack of vegetation.

   The upper reaches of the Yangtze River will be widely afforested to keep the river clean, Liu said.

   A group of key officials from the SEPA and other departments will oversee the implementation of the plan. 

   The Three Gorges dam project was started in 1993 and will last another eight years. When the dam begins storing water in 2003, a permanent ship's lock and the first group of power generators will become operational.