Nicholas Ning/Shanghai Daily news

The water supply stoppage in Harbin in Heilongjiang Province won't happen in Shanghai as the city has sufficient reserves, the Shanghai Water Authority said yesterday.
Although the city's water supply faces pollution problems from the upper reaches of source rivers and occasional oil spills, residents have been little affected, said Liang Hong, the authority's spokeswoman.
"Unlike Harbin, the city has two major fresh water sources, the Yangtze River and Huangpu River," Liang said. "That does not include hundreds of deep wells."
In Harbin, Heilongjiang's capital, authorities yesterday turned off the taps over concerns a chemical plant explosion might have polluted the Songhua River - the city's main water source. It triggered panic purchases of bottled water around the city.
Similar accidents have endangered Shanghai's water source, but no major incidents have been recorded.
"The city's tap water capacity is much bigger than demand and there are reserves at water plants and numerous water tanks at residential complexes and factories," said Ma Lei, an official with Shanghai Chengtou Corporation's water division.
The company controls most of the city's more than 30 water plants.
The Yangtze and Huangpu rivers supply the city with more than 6.3 million cubic meters of fresh water a day that is then treated. Some suburban districts have their own water sources, mainly smaller rivers.
Peak demand for fresh water in Shanghai in one day was recorded at 6 million cubic meters.
A huge reservoir is built along the banks of the Yangtze River with a holding capacity of 8.3 million cubic meters. Another one is under construction. It has a designed capacity of more than 14 million cubic meters.
The 900 wells across the city could help with an additional supply of 200,000 cubic meters per day in case major water sources are polluted.
Plus there are about 100,000-odd water tanks on top of residential buildings with a combined capacity of more than 1 million cubic meters.