Authorities in the Yangtze River Delta are calling for cross-region environmental legislation to achieve better water quality in Taihu Lake, China's third-largest freshwater lake, that has been plagued by pollution for years.

Legislation is being urged for the Taihu Lake basin area that covers two provinces and one municipality. Officials said administrative barriers among governments of the three different regions and their self-interests have hindered the continued improvement of Taihu Lake water quality, and that cross-region legislation is vital to ensure efficient cooperation among them.

Zhang Quan, director of the Shanghai municipal environmental protection bureau, has submitted a proposal to the ongoing NPC session, calling for the establishment of a central commission on the protection of Taihu Lake water quality and comprehensive cooperation among regions in the upper and lower reaches of the lake.

Although the three regions, including Jiangsu and Zhejiang provinces and Shanghai municipality, have done a lot in collectively fighting water pollution, efficient coordination is lacking, Zhang said. Self interests are usually prioritized above the overall improvement of Taihu Lake water quality, he said.

"For example, regions on the upper reaches of the lake sometimes disregard the interests of the lower reaches by discharging excessive pollutants into the lake in pursuit of local economic development," he said.

"That's why we need to promote environmental compensation so that the lower reaches would be compensated for any pollution caused by its neighbors in the upper reaches," he said.

The environmental compensation mechanism, which was already in place in Jiangsu, stipulates that cities on the upper reaches must compensate those in the lower reaches if their pollutant discharge exceeds the maximum limit.

In the first round of compensation finalized at the end of 2008, provincial capital Nanjing paid 18,000 yuan ($2,600) to the city of Changzhou, which in turn paid 180,000 yuan to Wuxi on the lower reaches of the lake.

The mechanism needs to be extended to the whole Taihu Lake area, and more needs to be done in overall pollution control and information sharing among the regions, Zhang said.

He also said the current governing body for the area is affiliated with the Ministry of Water Resources and is only responsible for flood prevention and utilization of water resources. It cannot address water pollution problems that are becoming increasingly serious today.

Zhang's call has won support from Mao Xiaoping, mayor of Wuxi, Jiangsu province.

"It is crystal clear that water pollution is not simply the responsibility of a single city, and to cure that problem, it needs concerted efforts from all those involved," he said.

Mao also said his government has closed more factories than it has allowed to open in recent years, in an effort to curb industrial pollution.

Taihu Lake has witnessed massive outbreaks of blue-green algae in recent years despite efforts to cut pollution discharges into the lake.

One such outbreak disrupted water supplies to 1 million residents of Wuxi in 2007.