Monday, May 23, 2011

Reservoirs have little in reserve

Reservoirs have little in reserve
By Li Yao and Zhou Lihua
China Daily, 2011-05-24

Recent rainfall not sufficient to satiate increasing demand

BEIJING - Nearly 1,600 water reservoirs in Central China's Hubei
province are running at the minimum water level needed for operation,
forecasting a prolonged dry spell over the parched province, the local
drought relief authority said on Monday.

As of Sunday, the province's reservoir water storage stood at 9.75
billion cubic meters, a 40-percent decrease from last year. The low
water level makes it unlikely the drought can be eased, with two earlier
rounds of rainfall but no more forecast in May, the statement said.

The lasting drought has so far affected 889,000 hectares of crops and
left 761,000 people and 175,000 livestock in the province short of
drinking water.

Reservoirs have little in reserve

Hanjiang River, a major branch of the Yangtze River in Hubei, has almost
dried up and put a huge strain on irrigation supplies for paddy fields
along its range.

The water level of the Danjiangkou Reservoir, part of China's massive
South-to-North Water Diversion Project, dropped to 4 meters below the
minimum level.

Honghu Lake, the biggest lake in the province, has seen one-fourth of
its 35,300-hectare area dry up, stranding thousands of fishing boats.
The water level reaches 30 cm in the deepest areas, where it used to
stand at two to three meters.

Hubei Governor Wang Guosheng, also chief of the Yangtze River flood
control and drought relief headquarters, said on Monday that the river
has experienced the lowest level of rainfall since 1961, with 40 to 60
percent less rainfall on average in drought-stricken provinces in its
middle and lower reaches including Hubei, Hunan and Jiangxi.

The headquarters' hydrographic office predicts that heavier rainfall
over the Yangtze River basin during the flood period (May to October)
may increase the flood risk upstream.

"Even in a severe drought, we have to be alert about flood control along
the Yangtze River," Wang said.

Chang Xiaolin, a professor at the College of Water Resources and
Hydroelectric Engineering of Wuhan University, told China Daily that the
situation is due to shrinking amounts of rainfall, while the demand for
water - for drinking, irrigation and power generation - is stable or

The construction of the reservoir system did not take long-term water
conservation into consideration. Excessive water collected in one year
can't be saved in preparation for possible droughts next year, Chang said.

"But to build bigger reservoirs and enable them to hold a huge amount of
water for future use, other factors have to be considered, including
submerged land, the evacuation of affected residents and financial costs."

Tighter control over the conversion of lakes and wetland to farmland or
commercial use, and better protection of vegetation, will also help
enhance the overall capacities and flexibility of water storage to
alleviate droughts and floods, he added.

To relieve the devastating drought in the province, the Three Gorges
Dam, the largest hydroelectric project in the world, has discharged 17
billion cu m of water to downstream areas since January, and will keep
the discharge rate above 11,000 cu m a second from May 25 to June 10.

Xinhua and Guo Rui contributed to this story.

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