SWOLLEN YANGTZE

In central Hubei Province, the government raised the flood alert to the second highest level and ordered relevant agencies and rescuers to remain vigilant.

Photo taken on July 26, 2010 shows a flood-ravaged amusement park at Ciqikou ancient town in southwest China's Chongqing Municipality. [Xinhua]

The water flow rate into the Danjiangkou Reservoir from the Hanjiang River, the second largest branch of the Yangtze River, peaked at the highest in almost three decades, the provincial disaster relief headquarters said, describing the flood-control situation as "very severe."

The reservoir's water level is expected to rise to at least 155 meters on Tuesday, about 6 meters above the reservoir's danger level.

Authorities have ordered the operation of a flood buffer system -- the diversion of water flows into an emergency reservoir capable of holding 1.6 billion cubic meters of water.

Vice Governor Zhao Bin told a provincial disaster relief meeting on Monday that measures should be strengthened to ensure that "no dike breaches, no dam bursts and losses are kept to the minimum."

Water flow rates at the Three Gorges Dam, meanwhile, at the mainstream of the upper Yangtze River -- China's longest river, rose Monday after a three-day lull.

The water flow rate hit 40,500 cubic meters per second Monday morning, and it is expected to continue to rise until it peaks on Tuesday.

Wu Daoxi, head of the Yangtze River Flood Control Office, told Xinhua that the water level at the reservoir behind the Three Gorges dam may reach 161.5 meters on July 30, a new record for the year and only about 13.5 meters under the reservoir's maximum holding capacity.

Last Tuesday, the flow of the Yangtze River exceeded the rate during the 1998 floods that killed 4,150 people and was the highest since the dam became fully operational in 2009.

The dam managed to buffer the worst of the floods.

Wu has ordered engineers to increase the discharge volume of the dam, a move that would relieve pressure at the dam but pose challenges downstream.

Disaster prevention efforts were especially intensified in Hubei's provincial capital of Wuhan City, the junction of the Hanjiang River and the Yangtze on the downstream of the Three Gorges Dam.

About 7,551 workers were mobilized to check the dikes and other flood-control systems in the central China city -- with 9.1 million residents -- around the clock.