Ground was broken yesterday in a crucial subproject in Henan Province, the middle line of China's ambitious south-to-north water diversion project.

Upon completion in late March 2010, the project will have two tunnels through the riverbed of the Yellow River, China's second longest, letting water flow from the Yangtze River, China's longest, in the south to the northern bank areas of the Yellow River.

Launching the cross-river project, along with the dam-heightening work that was launched on Monday in neighboring Hubei Province, will bring the construction of the middle line into full swing in the years ahead. The project was explained by Ning Yuan, deputy director of a special office responsible for the major diversion project under the State Council. He spoke at the groundbreaking ceremony in Wenxian County, west of Zhengzhou, capital of Henan.

The tunnels, stretching for 19.3 kilometers, will be laid through silt and clay in the river bottom. The cost is estimated at 3.137 billion yuan (US$387 million), according to Ning.

With a diameter of 7 meters, each of the tunnels has a designed water flow-capacity of between 265 cubic meters per second and 320 cubic meters per second.

The two tunnels will be among the largest of their kind in the world and will be the first to be excavated by using state-of-the-art tunnel shield technology, said Ning.

The dam project in Hubei will increase the height of the 1950s Danjiangkou Reservoir, the source of the diversion project, by nearly 15 meters. It is expected to hold 11.6 billion cubic meters than the current reservoir.

The eastern section will transfer water from east China's Jiangsu Province along the Beijing-Hangzhou Grand Canal, built more than 1,500 years ago, to Shandong and neighboring areas, before finally reaching Tianjin.

(Xinhua News Agency September 28, 2005)