The most serious salty tide in two decades - a result of a severe drought in south China - is posing a threat to potable water supplies in major cities in Guangdong Province.

The tide will not possibly ebb until the May rainfalls, said Chen Xiaohong, chief of the Department of Water Resources and Environment under Zhongshan University.

Rain has been scarce for several months in the province, raising concerns of inadequate fresh water, especially in Panyu, a district in Guangzhou, and some major cities including Zhuhai and Zhongshan.

Residents there are facing a worsening shortage of potable water and some are even drinking salty water.

Government sources said the salty tide appeared in Panyu in early February; and as many as 40 townships have been forced to limit water supply.

Residents in the district pointed out that the drinking water shortage started as early as in November last year because of the drought.

"The flow of water was decreasing, sometimes was even cut off," said a man living in Nanchun Town of Panyu.

In Zhuhai, another affected area, the water works announced that potable water would only be supplied in the morning and the evening, about five hours a day.

In Zhongshan, the local water company said the tide was the most severe in the past century.

However, the water works in Panyu said the tide had ebbed, and water supply has returned to normal.

Over the past decade, the river bed in the area was over excavated for urban construction in the Pearl River Delta.

When the water from the sea flows inland through the river or other channels, the deep river bed is unable to block the flow.

(China Daily March 5, 2004)