Supply could be assured by stronger conservation efforts, more recycling and bringing in water from neighbouring provinces, Ma said.

China plans to pump water from southern rivers to the parched north in a project known as the South-North water diversion scheme but environmentalists have raised doubts about the massive scheme's efficacy given serious pollution in China's waterways.

On Tuesday, state media reported that the Yangtze river -- touted as a major water source for the scheme -- was "cancerous" with pollution and could die within five years.