Concerns over water contamination have prompted Shenzhen officials to plan the demolition of two dog shelters, causing animal protection organizations to call for legislation on the care of street dogs.

The shelters, which house more than 300 dogs, are less than 100 meters from the Xili water reservoir, a major drinking water supply for more than 5 million people in two urban districts in the city in Guangdong province.

Lei Bo from Nanshan district environmental agency said animal waste from the shelter runs off into the reservoir, polluting the water.

"We have notified the shelter to move," she said. "After that, law enforcement will remove the buildings."

The dogs are available for adoption. If owners are not found, the animals will be put down, Lei said.

She added that the noise and smell from the shelter have also upset nearby residents.

The shelters are managed by two dog protection organizations, Futian Ai Pet Association and Shenzhen Dog Protection Association, the city's only registered dog protection NGOs.

A volunteer, who gave only his surname as Fu, said the dog waste is carefully treated and does not pose a threat to the environment.

"The urine is taken in by liquid-absorbing bricks," he said. "We also clean the shelter every day, and the used water is treated in a septic tank.

"Excrement is collected every day for waste treatment," he added.

However, no matter how clean the shelter has been kept, city regulations specify that no animals can be raised within a water resource area.

The animal protection associations say they cannot afford to move, and the lack of legislation on the care of street dogs remains a headache.

In the past year, Shenzhen Dog Protection Association has moved several times, and has spent more than 200,000 yuan ($32,600), earned mostly from donations, on construction and operating costs to care for more than 150 dogs.

"We have requested government compensation. But it has been denied," Fu said.

The district's urban management office said the government can do nothing to deal with street dogs and therefore outsourced the care to non-governmental organizations.

The organizations receive a weekly government subsidy after accepting a street dog, the office said.

Huang Hui, president of Futian Ai Pet Association, said it takes more than a week to find most dogs a home, and volunteers usually foot the bill.

Compared to Beijing or Shanghai, which have regulations specifying rights and duties for managing street dogs, Shenzhen is lagging behind, said Huang.

Local regulations fail to specify who has the responsibility to take care of the dogs, he added.

According to Shenzhen's urban management bureau, more specific guidelines for handling street dogs are under discussion and have been listed in the city's legislative agenda.

Li Yifei contributed to this story.