The annual drawing-off event in the Dujiangyan City at the Pure Brightness Festival (April 5) started in the year of 978 to mark Li Bing and his son who led the construction of the Dujiangyan Water Conservancy Works to benefit the Chengdu Plain. In ancient times, people usually used wood and raft to build provisional cofferdams in winter so as to block the Minjiang River water for repairing riverbed and reinforcing the dikes. At the Pure Brightness Festival, a grand ceremony would be held to worship Li Bing and his son, pray for an abundant harvest of all food crops as well as for stability and peace. The cofferdam world then be removed to let in the Minjiang River water to irrigate the vast stretches of cultivated land on the Chengdu Plain. After 1957, a water gate was built on the Dujiangyan Canal to replace the cofferdam. As a result, the ceremony of drawing off water by cutting the cofferdam was no longer held. In 1990, the Dujiangyan City restored the event by holding mock cofferdam cutting and traditional worship activities. Lantern exhibitions, street performances, flower and goods trade activities were added. The endeavor has helped to attract a great deal of domestic and overseas tourists.
