Ten newly drilled deep wells are now ready to serve as emergency water sources for Shanghai as a part of the city's underground water project.

The city will drill more advanced deep wells below large residential areas to ensure local residents' access to safe drinking water in the event of an unexpected disaster, Fu Jianrong, spokesman of the Shanghai Water Authority (SWA), said on Monday.

"These wells are only backups when our existing water supply is cut off because of unpredictable factors," said Fu. "Currently, we've started the project at eight colleges, rather than residential areas, to see how it goes."

The 10 newly built wells are at eight universities in the city, including Fudan University, Tongji University, Shanghai University and Shanghai Ocean University.

"Authorities decided on the project plan in July and they officially started to dig the well at our university in August," said Guo Bin, a staff member in charge of logistics at Shanghai Ocean University. "The well is about 240 meters deep. Operating devices will be installed in early October."

Guo said the university cannot use the well unless they receive permission from both the municipal government and the SWA.

"However, the university is responsible for the daily maintenance of the well, such as to take some water from the well and recharge it to prevent it from becoming polluted or causing any ground to sink."

Shanghai has strict regulations regarding underground water pumping.

David Sutton, an environmental expert and China regional manager of the Britain-based consulting company Environmental Resources Management, said strict regulations are applied because the low-lying city is likely to suffer sinkholes and other damage if too much underground water is taken.

The quota for Shanghai's groundwater pumping is within 20 million cubic meters this year, and the city has to put more than 18 million cu m of water back to keep the balance, figures provided by the SWA show.

"Before being connected to the tap-water supply, some residents in suburban Shanghai once relied on well water in their daily life," said Deng Wu, another officer with the SWA. "We now have to recharge these abandoned wells."

Sutton said Shanghai's underwater project also reminds him of Istanbul's Basilica Cistern, a huge cistern built beneath the city to solve its water-supply issue.

"It appears to me that Shanghai is experimenting with a modern version of the Basilica Cistern, but with more innovation," he said.