The first phase of the middle route for China’s South-to-North Water Diversion project will soon begin operation, transferring water from the Hanjiang River to thirsty cities in north China.
The middle diversion route plans an initial yearly transfer of 9.5 billion cubic meters of water to Beijing, Tianjin, Henan and Hebei, key areas for the country’s industrial and agricultural output which have been increasingly plagued by water shortage.
With an estimated investment of 500 billion yuan (81 billion US dollars), the south-to-north water diversion project has east, middle and west routes, transferring water to north China from the lower, middle and upper reaches of the Yangtze River, the longest in the country.
The first phase of the east route started operation last year, transporting water to Shandong Province. The west route has not yet started construction.
Fears about unfavorable impacts of the project to both local economy and environment remain in the water source areas of the middle route.
With a population of 19 million, or one third of the whole Hubei province, the lower and middle reaches of Hanjiang are important grain production and industrial bases. The region contributes 35 per cent of Hubei’s gross domestic product.
The loss of such a huge amount of water is estimated to reduce 26 per cent of the environmental capacity of the lower and middle reaches. Thus it will weaken the self-cleaning ability and increase difficulty in water pollution control in these sections of the waterway.
If the amount of pollutants along the river trunk keeps unchanged and water in its branches does not improve, the overall water quality in the Danjiangkou dam’s downstream sections will further deteriorate, said Guo Zhigao, head of the south-to-north water diversion bureau of central China’s Hubei Province.
Algae blooms, partly due to industrial pollution, are feared to occur more frequently than before in the lower section of the river.
Since the 1990s, algae blooms have occurred repeatedly in the lower section of the 1,577-km-long Hanjiang River, the largest tributary of the Yangtze River. Hanjiang originates in the Qinling Mountains in Shaanxi Province. Its water remains fairly good in the upper stretch.
The diversion project will cause the water level downstream to fall and thus wetlands to shrink and affect biological diversity, said the bureau.
The original Danjiangkou dam was completed in 1973 with a height of 162 meters. To serve water diversion, the dam has been heightened to 176.6 meters.
After water diversion, the water level of the river in Xiangyang City, the first big city downstream from the dam, will drop by 41 cm and by 78 cm in October, according to a study on the project’s impact on ecological environment of Xiangyang, conducted by a research center under the Ministry of Water Resources.
“Normally, the water flow discharged from the Danjiangkou Dam should be no less than 500 cubic meters per second, but sometimes it slows to around 360 cubic meters per second,” said Zhou Kaihua, deputy head of the Water Authority of Yicheng City, under the jurisdiction of Xiangyang.
This year, the water level of the river at Yicheng fell by 70 cm, which caused irrigation problems and temporary failure of two water plants to reach water, according to Zhou.
Hubei has been frequently hit by drought in the past few years.
A grave drought hit the lower and middle reaches of the river this summer, cause drinking water shortage in several cities and nearly 1,000 small rivers to run dry.
In the long run, the transferred volume of the middle route will increase to 13 billion cubic meters per year. Meanwhile, another project under construction at Hanjiang’s upper section will divert a maximum of 1.5 billion cubic meters of water each year to the Weihe River to ease water supply strains in southern Shaanxi.
To tackle the impacts of the middle diversion route, authorities have invested 11 billion yuan in carrying out four “compensation” projects.
They include the construction of a canal to transfer water from Yangtze to the lower section of Hanjiang and the Xinglong dam in the downstream to ensure irrigation, shipping and water supply in cities.
Some experts have suggested studying the possibility of diverting water from the Three Gorges Reservoir to the Danjiangkou Reservoir, via a new canal.
Meanwhile, local authorities in the water source areas have shut down more than 1,000 polluting plants to ensure good water quality in the Danjiangkou reservoir.
Beneficiaries of the water diversion Beijing and Tianjin have planned to support the economic and social development of the water source areas and help them improve ecological environment.
From 2014 to 2020, Beijing municipal government will earmark 250 million yuan annually to Hubei and Henan each to help them promote ecological economy, upgrade industries and improve waste treatment capabilities.
