Workers will break ground today in the neighboring Henan Province for the construction of one of the most important subprojects of the middle line of China's ambitious south-to-north water diversion project.
Ground was also broken yesterday in Hubei for the project that will direct water to key cities in north China facing worsening water shortages.
"The kick off of the two projects on the Hanjiang and the Yellow rivers will bring construction of the middle line into full swing in the years to come," Ning Yuan, deputy director of a special office responsible for the major diversion project under the State Council, said yesterday at the groundbreaking ceremony held on the Danjiangkou Reservoir.
The south-to-north water diversion project consists of three south-to-north canals, each spanning more than 1,000 kilometers across the eastern, middle and western parts of the country.
To be built section by section in three phases, the three canals will link the country's four major rivers together the Yangtze River, Yellow River, Huaihe River and Haihe River -- as a way to optimize water resources throughout China.
At Danjiangkou Reservoir, the source for the middle line, earth was broken to heighten its dam by 14.6 meters from the present 162 meters after parts of the crest of the old dam were blown up to create a new base on top.
Sitting upstream in the middle reaches of the Hanjiang, the longest tributary of the Yangtze, China's longest river, the dam will help increase 11.6 billion cubic meters of water inside the reservoir if heightened.
It will cost 2.42 billion yuan (US$299 million) and take five and a half years to complete, experts said.
In Henan, the construction of two huge tunnels designed to be built through the riverbed of the Yellow River, some 60 meters below China's second longest river, is scheduled to start today in a village about 30 kilometers west of Zhengzhou, capital of the province.
"It will take more than four years to complete the entire huge cross-river project, which will stretch for 19.3 kilometers from south of the river to the north bank, including the two 3.5-kilometre-long tunnels," experts said. "Each has a diameter of 7 meters to be laid through silt and clay of the river bottom, at an estimated expense of up to 3.137 billion yuan (US$386 million)."
Each of the tunnels has a designed water flow capacity of at least 265 cubic metres per second.
But Ning admitted that they will face technological challenges. In Danjiangkou, construction has to be done while the reservoir and all its water control facilities are operating normally.
"One of the greatest challenges is how to integrate the new cement structure with that of the old dam built in the 1970s," he added.
In Henan, he said the two tunnels will also be among the largest of its kind in the world. "They will also be the first of its type to be excavated by using the world's advanced tunnel shield technology."
Furthermore, up to 400,000 residents, mostly from Hubei and Henan along the middle line, will have to be relocated for the construction in the years to come.
Taking water from Danjiangkou Reservoir, the middle line will pass through Hubei, Henan and Hebei provinces to Zhengzhou, Shijiazhuang, Beijing and Tianjin.
The eastern line is designed to transfer water from East China's Jiangsu Province along the Beijing-Hangzhou Grand Canal to Shandong and neighboring areas before finally reaching Tianjin.
Specific details about the western line are yet to be finalized.
Construction of the first phase of the eastern and middle routes were officially started in 2002 and 2003.
(China Daily September 27, 2005)
