China's second largest freshwater lake, Dongting Lake, is on flood alert Wednesday as the year's biggest Yangtze River flood peak is expected to surpass the lake's water level by nearly two meters.

The cities of Changde, Yiyang and Yueyang in the lake area have been warned to watch out for floods and safeguard embankments, after days of torrential rain in the southwestern Sichuan and Guizhou provinces and Chongqing municipality has caused the upper reaches of the Yangtze to swell.

The water flow at Cuntan Hydrological Station surged to 58,200 cubic meters per second Wednesday morning from 28,700 cubic meters per second on Sunday, Sept. 5. The water level has risen from 172.75 meters to 183.26 meters, 2.76 meters above the warning level.

The Yangtze River Hydrological Bureau predicts that water flow at the Yichang Hydrological Station will reach 61,000 cubic meters per second when Yangtze's flood peak is to arrive in Hubei Province at around 8:00 pm on Wednesday.

The upper reaches of the Yangtze River, China's longest, have flooded after continuous torrential rains that started on Sept. 2.

After the flood crest passed the southwestern Chongqing Municipality Tuesday afternoon, Hunan and Hubei provinces were placed on flood alert. Local flood control authorities have increased patrols along dams and reinforced all reservoirs.