People break the dam to unleash water at the ceremony.

The 2013 China Dujiangyan Qingming Water-Releasing Festival, together with the first Source of Tianfu Water Culture Tourism Festival, kicked off in Chengdu's Dujiangyan on April 4 in Sichuan province.

The water-releasing festival is a ceremony dating back 1,000 years. It celebrates the completion of the Dujiangyan irrigation system and commemorates its designer Li Bing.

According to the historical record, ancient people living along the banks of the Minjiang River were plagued by annual flooding. The Dujiangyan dam system was built in 256 BC to tame the Minjiang River's frequent flooding. The dam has stood for nearly 2,300 years, diverting water to irrigate nearly 70,000 hectares of farmland that produces almost one-third of the province's grain. It is considered to be the oldest functioning water-control project in the world.

The water system was included on the list of UNESCO world heritage sites in 2000. The Dujiangyan Qingming Water-Releasing Festival was listed among the first batch of national intangible cultural heritage projects in 2006.

During the opening ceremony, a landscape show was presented to audiences to tell the history of Dujiangyan. The show featured a new artistic style that was more appealing and attractive than the traditional stage performance. Thousands of visitors from home and abroad came to enjoy the show.

At the beginning of the ceremony, 38 children from as many as 37 districts in Dujiangyan county and Shanghai municipality released Kongming lanterns to pray for the prosperity of Dujiangyan, Shanghai, and the nation as a whole.

Dujiangyan was hit hard during the 2008 Wenchuan earthquake. As 2013 marks the fifth year after the earthquake, Dujiangyan is paying its respects to Shanghai for its help in reconstructing their homeland.

According to a local official, this year's water-releasing festival will last for a whole year. The organizer will host a series of tourism activities, including a calligraphy and painting exhibition, tea-leaf picking activities and bike riding events.

Audiences cheer at the water-releasing ceremony.

Children release Kongming lanterns at the water-releasing ceremony.