Sluices were lifted up once again on Tuesday in three reservoirs in Beijing's neighboring Hebei province to channel water to the capital through the Beijing-Shijiazhuang section, an emergency part of the South-to-North Water Diversion project, for ensuring the city's water supply.

It will take about 10 days for 200 million cubic meters of water to flow into Beijing, sources said, adding that the supply would last until November.

This is the second time water from Hebei has been used as a stopgap for shortages in Beijing since the 307-kilometer-long canal was put into use in Sept 2008. Completion of the entire central is scheduled for 2014.

The canal supplied up to 435 million cu m of water to Beijing for months in 2008, 65 percent of the total Beijing needed to meet its minimum demand for urban residents in its worst water shortage season.

Since then, the water it has brought into Beijing amounts to roughly one-third of the city's total everyday water needs. With the borrowed water, Beijing has reduced its exploitation of ground water, which has decreased land subsidence.

After years of delay, construction on SNWD is proceeding at full capacity, thanks to an unprecedented investment boom.

Since then, authorities have been busy with two key factors challenging the project – the 540,000 people to be relocated, including 330,000 of them from Hubei and Henan provinces, and serious industrial wastes around its eastern route.

To date, more than 23,000 people have been moved along the central route, while construction of 426 pollution-control projects have begun on the eastern route.

The SNWD project, an effort that will take at least 40 years to complete, was designed to bring water from the water-rich Yangtze River basin to the parched north, along three canals each stretching more than 1,000 km. The diversion will ultimately connect the country's Yangtze, Huaihe, Yellow and Haihe rivers via three water-diversion channels. Construction of the eastern route began in December 2002 and construction of the first phase of the central route began a year later.

The western route, meant to replenish the Yellow River with water diverted from the upper reaches of the Yangtze River, is still on the drawing board.

According to SNWD's office, the first phase of the eastern route will begin to provide water in 2013, and the central canal is expected to begin providing water in 2014.