Zhuhai in Guangdong Province and the Macao Special Administrative Region (SAR) are under threat from a serious saltwater tide that is likely to worsen over the next two months, the provincial water resource department said Thursday.

The saltwater tide arrived in Zhuhai in the first half of November, earlier than the usual saltwater tide season from December to February.

Last month, the city's main water source, Pinggang Water Pumping Station, was rendered incapable of pumping qualified fresh water for 171 hours. This seriously affected Zhuhai people's daily lives, and the impact extended throughout the Pearl River Delta.

Currently, the whole city has stores of 25 million cu m of fresh water, 7 million cu m less than the same period last year.

Director of the Guangdong provincial water resource department Huang Boqing said the department and other relevant organizations would do their best to control the saltwater tides and increase the amount of fresh water.

Huang said construction of hydropower stations in the upper reaches of Xijiang and Beijiang rivers - two tributaries of the Pearl River - should be slowed down, because they would block a large amount of fresh water and worsen saltwater tides in the river's lower reaches.

Other provinces in the river's upper reaches diverted about 10 million cu m of fresh water to Zhuhai from November 20 to December 4.

In addition, Zhuhai would complete a large reservoir by next October, and construction of another would begin next year and finish in 2010.

However, many individuals are dredging river sands from the Pearl River Delta for profits, causing the riverbed to lower.

"The riverbed of Beijiang River is 30 percent lower than two decades ago," He Zhibo, a senior engineer of Zhujiang (Pearl River) water resource commission, told China Daily yesterday.

The lowered riverbed cannot buffer saltwater tides. And if the river sand dredging continues, all government efforts to stem the tides would be wasted, he said.