Beijing readies for influx of new water from south

In just 88 days, Beijing residents will finally be able to use the water from the South-to-North Water Diversion Project, a series of canals and pipes six decades in the making, designed to pull water from China's wet south to its arid north.

The middle route of the project, which officially began construction at the end of 2003, will open the flow gates at the end of October.

At that point, water diverted from Danjiangkou Reservoir in Hubei Province will reach most Beijing households through 20 water plants after 15 days of travel along 1,276 kilometers of canals and pipes.

If everything goes smoothly, the route will send 1.05 billion cubic meters of water to Beijing annually for the first several years of its operation, an amount equivalent to nearly 30 percent of the city's annual water consumption.

"Nearly all the rivers and lakes in Beijing are anticipating the water, which is hoped to bring some vitality to the stagnant water [sources around the capital]," Zhu Chendong, former chief engineer with the Beijing Water Authority, was quoted as saying in a recent report by Caijing magazine.

This hard-won water is expected to help relieve the city's water shortage and help repair local aquatic ecosystems.

Meanwhile, infrastructure years in the making, built in preparation of the water's arrival, will also face its first test.

Hardware prep

Previously, Beijing's water was supplied mainly from underground reserves and surface water in reservoirs north of the city. But with the arrival of water from Danjiangkou, these patterns will change.

The city began planning and constructing new water supply networks more than 10 years ago. Water from Danjiangkou will enter the city through Fangshan district in West Beijing into massive underground concrete pipes 4 meters in diameter.

After an 80 kilometer trip northward, across 32 rivers and streams, 12 main roads, 11 railroads and subway Line 1, the water will finally arrive at its terminal stop, Tuancheng Lake in the Summer Palace.

The lake, apart from being a water source for five major water plants in Beijing, is also a regulating pool for discharging and drawing water through a diversion canal connected to the Miyun Reservoir, the city's largest surface water resource.

To shorten the distance for other water plants accessing the water from the south, the city has also built a connection loop, laying pipes deep underground along almost the entire length of the city's Fifth Ring Road.

In order to adapt Beijing's water supply system to the water from the south, which is more acidic than the city's current supplies, the city laid or rust-proofed 2,200 kilometers of pipes, according to Hu Bo, an official from the Beijing Water Authority's water supply division.

The acidic water from the south could lead to yellow tap water in Beijing by eroding sediments accumulated in pipes that have seen decades of harder water.

This in fact happened early in 2008 after Beijing diverted water from southern parts of Hebei Province, when a number of households reported yellow running water.

Learning from this experience, the authorities have spent time figuring out how to adapt southern water to northern pipes, assembling scientists and experts in a small laboratory near the Danjiangkou Reservoir since 2009. The efforts have paid off, making sure that Beijing's water system will be able to handle the influx of southern water.

As part of the plan for introducing new water into the system, supplies diverted from the south will first mix with local water in water plants at a 1:4 ration. The ration will then be gradually adjusted until it reaches 1:1 at some point next year.

As part of its preparation efforts, the authorities have also built a production and storage center for emergency drinking water, with the capacity to provide drinking water for 500,000 people a day.

Water recharge

The water diverted from the south will mainly be used for residential and industrial use in the city's central districts, although eventually water will be supplied to 15 of Beijing's administrative subdivisions (excepting only rural Yanqing county).

Portions of the water will also be set aside for ecological and environmental demand. One major consideration is recharging lakes and exhausted groundwater. Nevertheless, this idea has generated controversy over whether the water, obtained at price of 200 billion yuan ($32 billion) worth investment and the relocation of 340,000 people, will be realizing its true value if put to such a use.