The flood crest of the Huaihe River surpassed the danger mark at Wangjiaba, a hydrological station in east China's Anhui province on Monday, intensifying risks of the river bursting its banks.
The water level monitored at Wangjiaba was 63 cm above the danger mark on Monday morning, when the flow at 3,910 cubic meters per second.
The provincial Flood Control and Drought Relief Headquarters warned the water level could rise by another 30 cm by Tuesday, when the flood peak was expected to reach Wangjiaba.
More that 20,000 hectares of farmland have been inundated since the river began to swell on Saturday, according to the headquarters, which has mobilized more than 2,700 people to patrol the embankments.
The flood was triggered by heavy rainfall in the catchment area since Wednesday. The weather cleared on Monday and the provincial observatory was forecasting no heavy rain in near future.
The headquarters on Monday called on government institutions to allocate more personnel to flood control efforts along the embankment.
The sixth longest river in China is one of the most flood prone in the country. Its first flood this year was on April 22, and the highest water level monitored at Wangjiaba was 27.78 meters. It was the most extensive spring flooding since 1964.