SHANGHAI, Jun 17 -- SHANGHAI may face water shortages this summer because its growing population will need an extra 340,000 cubic meters of water every day this summer, officials predict.

This could lead to shortages in outlying suburbs where infrastructure has not kept pace with expansion, the Shanghai Water Authority said yesterday.

Total demand is expected to be 10.35 million cubic meters on "extreme hot days," when temperatures top 35 degrees Celsius, said Meng Mingqun, vice chief of the authority's water supply administration.

The estimated demand is one million cubic meters short of the city's top capacity.

"The overall supply and demand can balance," said Meng. "But there's still the possibility that supply in some areas could be challenged due to the outdated water infrastructure there."

Suburbs are likely to be hit where rapid urbanization and industrialization spurs demand, and where fresh water supply, distribution networks and water plant capacity have failed to catch up, he said.

Meng noted that some engineering projects are scheduled to finish by next month to increase the capacity.

Among them, Linjiang Water Plant in Minhang District will be able to increase its supply by 150,000 cubic meters a day when the distribution network outside the plant finishes expansion. Currently the 600,000-cubic-meter plant can't run at its designed capacity.

Water suppliers will also monitor the environment at the city's two major water sources, especially the Huangpu River which accounts for 70 percent of fresh water supply but is prone to pollutants from its upper reaches. The Yangtze River is cleaner and has a bigger water flow.