During the 11th Five-Year-Plan period (2006-2010), the municipal government will target flowing pollution – sewage, oil-tainted water and solid trash – from ships and boats, said a spokesman from the Municipal Commission of Communications.

"All newly built ships should discharge according to required standards, while old boats are required to undergo a technical overhaul so that the discharge of carbon dioxide and hydrocarbons will be lowered drastically to meet the standards for discharging before the year 2010," said the spokesman.

"Operators who fail to meet the standards for discharge will not allowed to ply the Three Gorges Reservoir and violators will be punished severely."

Each year, more than 100,000 ships and boats ply the Three Gorges Reservoir, of which 30,000 navigate and stop by Chongqing.

An estimate by the local environmental protection department shows that passing ships and boats leave behind 42,000 tons of trash, seven million tons of manure, 15 million tons of sewage and more than a million tons of oil-tainted water each year.