In China's water-hungry capital city, it is unusual for a massive water-saving project to cause a lot of controversy. But such is the case with the multimillion-dollar scheme to cover the lakebed in Yuanmingyuan -- Beijing's Old Summer Palace -- with impermeable membrane.

The project, which involves covering about 133 hectares of the lake's bottom, has led to an outcry from experts and residents who are worried about Beijing's underground water supply.

Park staff say that covering the bed will conserve water by preventing it from seeping into the ground.

"Without the membrane, we have to add water to the lake three times a year; with the membrane, just once," said a park official who requested anonymity. "This way, we can save a considerable amount of money as we don't have to buy so much water. This is significant because we are on a tight budget."

But many experts are questioning the advisability of the project.

"It is an ecological disaster and should be stopped immediately," Professor Zhang Zhengchun of Lanzhou University?told the People's Daily. "Covering the lake bed with impermeable membrane will cut off its connection with the underground water system."

Wu Bihu, a professor at Peking University, agreed. "The impermeable membrane will prevent the water from seeping into the ground, which will disturb Beijing's underground water system."

Ground subsidence resulting from water depletion in underground aquifers is already a serious problem in the capital. As of July 2004 more than 1,800 square kilometers had been affected, with ground sinkage damaging or destroying about 50 locations in the city, including factories, buildings and underground pipes, said Wei Lianwei, director of the Beijing Geological Survey Institute.

Last summer, Vice Mayor Lu Hao called ground subsidence a "major threat" to the city.

? Mei Ninghua, the director of the Beijing Cultural Relics Department, is also opposed to the project, albeit on different grounds: As a city heritage site, Yuanmingyuan must keep its original environment and appearance. "We have requested the park stop the project and send a special construction team on ancient buildings to investigate alternatives. We'll set up a task force to deal with this problem, explore options and propose a feasible plan," he said.

Yuanmingyuan, which was burned to the ground by Anglo-French forces in 1860, is located in the western suburbs of Beijing.

Park officials themselves are not entirely in agreement about the project.

Some say that an environmental impact assessment has been made and the scheme will do no harm.

"The project will not completely prevent water from seeping underground, so it will not disturb the underground water supply," Tang Li, of the park's administration office, told the Beijing News.

However, she declined to give details about the assessment report.

Another park official, Li Jingqi, director of the Yuanmingyuan Park Administration Office, admitted "There will be some impact on the environment but it will not be as severe as those experts have claimed."

The total spending on the membrane project is reportedly 150 million yuan(US$18 million), a figure Tang dismisses.

"The spending is not that much," she said, but gave no specific figures.

An online survey on the People's Daily's website showed 92.8 percent of those polled are against the project, while 3.0 percent agree it will save water.

The Beijing Environmental Protection Bureau (BEPB) has now intervened in the case. On Tuesday morning, officials from the Haidian District Environmental Protection Bureau and the BEPB's Assessment Department began investigating the site.

They have already ordered materials related to the project from the park authorities, which they will review to determine the potential harm to the environment.

The BEPB and district authorities said that an environmental impact assessment is a precondition to approval of all major projects. However, they cannot make a determination about calling a permanent halt to this one until the results of their investigation are analyzed.

They emphasized that if the project is found to be in violation of environmental protection standards, it will be shut down.

The park began work on the project on February 16.

"The main part of the project has been completed. It is unrealistic to put the brakes on now or remove the membrane," said Li Jingqi, according to People's Daily. "Whether the project will be stopped or the membrane removed will be decided by our boss," Li added.

No one available at the park by press time Wednesday was able to provide information on whether or how the work got under way without the required environmental impact assessment.

(China.org.cn, China Daily March 30, 2005)