China has altered a plan to build a hydropower dam on the Poyang Lake after the plan was criticized by academicians for its potential damage to the already fragile ecology.

The dry riverbed is seen as serious drought hit Ganjiang River in Nanchang of east China's Jiangxi Province, Jan. 12, 2012. [Xinhua photo]

But officials with the eastern province of Jiangxi, where Poyang, China's largest freshwater lake, is located, said they would still search for other water control facilities to halt water levels of Poyang declining, as the lake is a key water supply source for about a million people and a natural habitat for numerous migratory birds and aquatic species.

Over the past years, reduced rainfall, rampant sand dredging, and the building of about 29 dams at the upstream parts of the Yangtze River, have caused the size of the Poyang Lake to rapidly shrink, from 4,000 sq kms at its peak to 200 sq kms in January, with water levels plunging to a six-decade low of 7.93 meters.

"We now plan to build only sluice gates at the mouth of the lake where water flows into the Yangtze," said Zhu Laiyou, head of the Poyang water control projects construction office. "The gates will help maintain Poyang's water levels during the drought season."

Zhu said the project would improve the wetland ecology, boost fishery, and help develop tourism -- all being threatened amid the continuous decline of water levels during the drought seasons over the past few years.

The original water control plan was canned after 15 academicians submitted a report to the State Council opposing the proposal to construct a dam.

"The dam and its hydropower stations will bring disastrous damage to Poyang's ecology and wildlife," said Cao Wenxuan, a biologist with the Chinese Academy of Sciences and one of the leading signatories.

Cao said he also had doubts about the government's latest plan as the sluice gates would still narrow the lake's mouth by one third and result in rapid water flows that might disrupt the activities of fish.

Dai Nianhua, a backer of the project, said the issue at the table is not whether a water control project was needed but what to build and how to build it.

"People are talking about the ecological impact that a massive water control project might have on the wildlife but the problem is if the lake is left to continue to shrink, the fish and birds will lose their habitat already," said Dai, a fellow with the provincial academy of sciences of Jiangxi.

Poyang Lake is considered a major destination of migratory birds in the region, attracting more than 500,000 birds of 52 species including endangered hooded cranes and white-naped cranes, in the winter of 2011.

The lake is also home for near-extinct Yangtze river dolphins and many other endangered fishes. Some environmentalists estimate that about 70 percent of Poyang's fishery resources had been wiped out in the past three decades.

Chen Fu, a deputy head of Poyang fishery bureau, said at least five Yangtze River dolphins were found belly up in Poyang Lake last year.

The historic low water levels had forced lakeside residents to look for alternative water supplies and fishermen out of business.

Liu Guibao, a 46-year-old fisherman from the lakeside county of Duchang, said his income shrank by more than three quarters last year as only two months, instead of traditionally six, were good for fishing.

Hundreds of fishing boats in Liu's village had been left lying idle on dry lakebed since September.

Liu said that ironically he had to buy fish from the market this Chinese New Year, the first time in three decades of working as a fisherman.