Water-saving regulations are to be issued by Shenzhen, a thirsty southern city, to increase the use of recycled water.

"The regulation has been submitted to the Guangdong Provincial People's Congress after getting the green light from the local legislative body last year. It should come into effect in the second half of this year," Zhong Ming, deputy director of the city's Water Supply Department, said.

The regulation requires new residential quarters or office buildings of a certain scale to install recycled water systems, to be used for flushing toilets, greenbelt irrigation and cleaning roads.

"It's practical to spread the use of recycled water in the city because more than 70 residential quarters have special channels to collect waste water," he said.

Real estate developers in the city have invested more than 200 million yuan (US$24 million) since 1992 in installing a recycled water system at the request of the government.

"But all were left unused because of outdated technology, poor management and high cost," Zhong said.

The worst drought of the past half century has now compelled the city to press ahead with the scheme, which should only need limited investment.

The city's Water Resources Bureau spent less than 400,000 yuan (US$48,000) in a pilot project in a residential area to improve its existing recycled water system six months ago, and remarkable economic and social effects have so far been achieved.

Currently, nearly 700 tons of residential waste water a day are collected, generating some 500 tons of recycled water for use in other areas, said Weng Zhigang, director of the real estate management office of Zhongyin Garden, a complex with more than 1,000 households and about 42,000 square meters of offices.

At full capacity, the system should produce 700 tons, he added.

About 150 tons has been used to irrigate the 10,000-square-metre park inside the complex each day, and another 150 tons are used to flush toilets.

The management office, with the help of the related government department, is expected to sign a contract with the relevant local department to sell 300 tons of water to irrigate neighboring public gardens.

"Compared with drinking water, the cost of recycled water could be reduced by half to reach less than 1 yuan (US$12 cents) per ton. Since about one-third to a quarter of the water a family consumes every month is for flushing toilets, the system could help people save money," said Zhong.

It is estimated that if all the existing recycled water systems in the city were put into operation, it would save 30,000 tons of drinking water a day.

Nearly 5 million tons of drinking water, worth about 13 million yuan (US$1.58 million), were used for watering public greenery in an extremely dry November last year.

(China Daily January 14, 2005)