A total of 6 billion cubic meters of tap water are lost through leaking pipes every year in China, a country that faces chronic water shortages.

That's enough water to turn Beijing into a four-meter-deep swimming pool, or meet a year's demand for water in the provinces of Zhejiang, Fujian, Jiangxi and Hainan, the Guangzhou-based Southern Weekly reported Friday.

China's water problem is getting worse. This year, several provinces and municipalities along the Yangtze River which were previously rich in water resources, including Hunan, Hubei and Jiangxi, were hit by weeks of severe drought, leaving millions facing a shortage of drinking water and 166,000 hectares of farmland with no harvest. Drought also brought the threat of plague and higher grain prices.

Leaking pipes

The shortage makes the water leakage more unbearable. Leaking pipes resulted in a loss of 6 billion cubic meters of water in 2009,  and so far no one seems to be taking responsibility for it, according to the China Urban Construction Statistical Yearbook 2009.

Water pipe leakage is a problem that every country faces, but in China, the rate remains high and seems to be getting worse, the Southern Weekly reported.

The national leakage rate climbed by 1 percent each year starting from 2006 and hit 12 percent in 2008 and remained the same in 2009.

However, Liu Huizhong, a member of a Beijing-based nongovernmental organization that offers training to water pipe leakage inspectors, told the Global Times, "The leakage rate in average in China is actually as high as 20 percent."

But he added that the rate is not climbing.

Statistics showed that the US, Japan, France and Germany have leakage rates below 10 percent. Tokyo boasted a rate of 3.3 percent in 2007. But 10 provinces and municipalities in China had leakage rates above 13 percent in 2009, with that of Jilin Province as high as 23 percent.

"Tap water, unlike untreated water resources, are precious and costly due to the disinfection and cleansing involved," Zhang Shifeng, a researcher with the Institute of Geographic Sciences and Natural Resources Research in Beijing, said.

Leaking pipes also bring with them health hazards. "Pollutants can enter supply pipes and contaminate drinking water, especially when both water supply and sewage pipes are exposed," Ma Jun, a water expert and environmental advocate in Beijing, told the Global Times Monday.

In early April, several hundred residents in Jiangsu Province experienced vomiting, lethargy and symptoms similar to those of poisoning.
 Days later, the local government announced that they found leaks in water supply pipes and tap water polluted by effluents.

Deep-rooted reasons

"Aging is the main reason behind pipe leakages," Ma noted. "Other culprits include substandard pipes, unreasonable network distribution and land subsidence."

Water pipes laid out during the early stage of urban construction in China, mostly made of cast-iron, have now reached "old age" and are prone to erosion.

Repairing or renewing them requires money, but some waterworks groups, which are in charge of pipe maintenance, are unwilling to cover the high costs, Ma said.

Massive urban construction is another factor threatening the security of water supply pipes. "Large constructions like subway stations, often occurring where water supply pipes are laid, may break the pipes," Shen Dajun, with the China Institute of Water Resources and Hydropower Research, told the Global Times.

In recent years, "cities like Beijing, Shanghai and Suzhou, as a result of over-exploitation of underground water brought about by drought or water pollution, have experienced land subsidence, which in turn put water supply networks at risk," Ma said.

"Uneven subsidence, for example, results in uneven pressure on pipe joints," he explained.

No easy job

Leaking joints account for 30 percent of total leakages, which makes their detection very difficult, Liu Shuming with the School of Environment at Tsinghua University told the Southern Weekly.

One common practice used in detecting leakages is to listen for dripping sounds by facilities at night when there is much less outside noise, Liu Huizhong told the Global Times.

In other cases, inspectors have to rely on their experience to locate leakage points. For instance, if grass is seen to be more luxuriant in one spot than in its immediate surroundings, that means the underlying pipes may have been broken.

"Things have changed for the better, in view of the fact that some city had leakage rates of 50 percent in the past," Liu said. "More water supply companies have also set up their own professional leakage detection teams."

Possible solutions

To keep the leakage rate within acceptable limits, a reasonable water supply pressure has to be determined.  

"However, it is not as simple as the public thinks. We need to strike a balance between water supply pressure and leakage rate," Liu said. "If water pressure is strengthened, pipe leakage will climb; but if the pressure is too low, some households will have no tap water."

"No pipe can ensure zero leakage, but better quality pipes undoubtedly would help a lot," Liu added.

Renewing pipe networks involves digging and demolishing surrounding buildings, which needs money, Liu Shuming said. But who will cough up this cash?

In 2000, the State Council decided that pipes more than 50 years old should be replaced, and set up a dedicated fund for a replacement program. "But the program's execution is not very desirable. Some waterworks companies didn't replace their networks," said Liu Huizhong.

"Water supply and sewage treatment are public services. The government (in future) can set up public finances to cover water supply services and list the network in its budget," Xu Zongwei, deputy director of the Policy and Regulation Department of the Ministry of Housing and Urban-Rural Development, suggested.