According to the Sichuan Provincial Water Resources Department,from 8:00 am on August 11 to 10:00am on August 12,heavy rain lashed the west of Sichuan Basin and the eastern part of the Western Sichuan Plateau. Severe rainstorms occurred in Chengdu, Deyang, Mianyang, Guangyuan and Meishan. There were 1,192 rainfall stations in 85 counties which recorded rainfall exceeding 50mm,covering an area of 63,900 square kilometers and 564 rainfall stations in 61 counties that recorded rainfall exceeding 100mm, covering an area of 26,000 square meters. There are 66 rainfall stations in 17 counties recording more than 250 mm, covering an area of more than 1,500 square kilometers, with the largest Shifang Shigu station recording 463.8 mm.Affected by heavy rainfall, the water level of 20 rainfall stations in 14 rivers in the province rose by more than 5 meters.

Main works of Dujiangyan Irrigation System(photo/Sun Jian)

Yuzui in flood discharge 

The flood peak of Minjiang River in Sichuan Province,triggered by heavy rainfall,formed in the Dujiangyan Irrigation System built more than 2,000 years ago. According to the Dujiangyan administration,the maximum flow on that day was 1600 m³/s.Ahead of the Li Bing Culture Festival,Dujiangyan Irrigation System faced severe flood peak pressure and had to release its waters.

Feishayan in flood discharge (photo/Sun Jian)

Baopingkou in flood discharge (photo/Sun Jian)

Dujiangyan Irrigation System is located on the Minjiang River in the west of Chengdu Plain.It was built in the last year of King Zhao of Qin Dynasty (about 256-251 BC).It is composed of Yuzui,Feishayan and Baopingkou.So far,it is the oldest and the only remaining irrigation system in use in the world.It doesn’t have a dam diversion.The Dujiangyan project contains modern scientific principles of "hydraulics" and "sediment dynamics", which embodies the hard-working, brave and intelligent spirit of ancient Chinese workers.（By Edina Liang)