China's largest freshwater lake will see droughts and shrink periodically due to hydro projects and fast urbanization, experts said.

Bao Chunhong, director of the Xingzi Hydrometric Station, points out water levels of previous years on a measuring pole last week. [China Daily]?

The water level of Poyang Lake, which connects to the Yangtze River, remained low from 2001 to 2010, compared with a decade ago, according to the Jiangxi Poyang Lake Hydrologic Bureau.

Bao Chunhong, director of the Xingzi Hydrometric Station, said in his 30 years of working experience, the lake has been hit by drought from time to time in the past and 2011 was "a severe drought year for the lake".

Dry weather is the main reason the lake has been shrinking, but the many water resource projects have added to the problem, Wang Shigang, deputy director of the Jiangxi Poyang Lake Hydrologic Bureau, told China Daily.

Precipitation in the lake hit a record low last year. The water level, as monitored by the Xingzi Hydrometric Station, of Jiangxi province, was 7.79 meters on Jan 6, more than 1 meter lower than the average level in the past six decades.

Rui Xiaofang, a professor at the College of Hydrology and Water Resources at Nanjing-based Hohai University, told China Daily that rapid urbanization is accelerating the problem.

"More people are pumping water from the lake, and there are improper activities, including filling the lake for construction projects and illegal dredging operations, and these have also been blamed for shrinkage in recent years," Rui said.

Three Gorges Dam, a major hydro project in the upper reaches of the Yangtze River, started releasing more water to ensure water levels and river traffic safety on the middle and lower reaches of the Yangtze on Jan 6, China Three Gorges Project Corp said in a statement.

The dam is expected to release 22.2 billion cubic meters of water to the middle and lower reaches during the dry season.

"Once the dam finishes discharging water, Poyang Lake will have a little relief from the drought," Wang said, adding that the water level monitored by Xingzi Hydrometric Station increased to 8.2 meters on Monday.

The lake's low water level is threatening the water supply in Duchang county, where about 120,000 residents could face water shortages.

Lei Hongsheng, general manager of the local tap water company, said the company added water pumps and extended pipes to guarantee the water supply.

Although more rain and snow are predicted in most central and eastern parts of the country, Wang Shigang, director of the lake's hydrologic bureau, was not optimistic and said even more rainfall would be needed.

It is not the first time that Poyang Lake has shrunk significantly. Its water level has remained alarmingly low during the dry season since 2003, according to the bureau.

Local experts and officials said they were considering measures to address the repeated water level problems.

A plan is under discussion to build a 2,800-meter-high dam between Poyang Lake and the Yangtze River to protect the lake from drought and flooding, Wang said, hoping the project will end the dwindling of water levels in the lake.