The water-releasing ceremony on the Qingming Festival is a folk custom in Dujiangyan City where the Dujiangyan Irrigation System, a UNESCO world cultural heritage site, is located. On Qingming Festival (one of the 24 Chinese solar terms) every year, grand ceremonies are held in commemoration of the completion of the irrigation system and its builder Li Bing, and at the same time to mark the beginning of a busy spring plowing season. The celebrations include official ceremonies and sacrificial rituals held by ordinary people.

In ancient times, a grand water-releasing ceremony would be held in Dujiangyan on Qingming Festival every year as a wish for a bumper harvest. This ceremony has been kept alive as a tradition in western Sichuan Plain. At the ceremony, local officials are on hand to present the water-releasing spectacle, accompanied by large-scale celebrations.

The water-releasing ceremony originated from the sacrificial ritual in honor of the God of Water before the irrigation system was built. At that time, floods frequently occurred, putting people on both banks of the river in great suffering. To seek protection from the God of Water, sacrificial rituals would be regularly held along the river. After the construction of the Dujiangyan Irrigation System, the Chengdu Plain was free from floods and people had ample food and clothing. To commemorate Li Bing and his son for their great work, people dedicated the sacrificial ceremonies to the father and son instead of the water. Local residents would spontaneously go to the Erwang (literally, two kings) Temple in honor of Li Bing and his son, where temple fairs (otherwise known as "Qingming Festival fairs") would be held.

In the past, when the dry season began in winter, special methods would be used to build a temporary cofferdam at the canal head. When the inner river was in repair, the water would be dammed out into the outer river, and vice versa. On the Qingming Festival, when the inner river irrigation area was in need of water for spring irrigation, a grand ceremony would be held at the canal head, during which the cofferdam would be removed, unleashing water into the irrigation channel. The ceremony was called "water releasing". During the Tang Dynasty, a "water-releasing ceremony involving an ox sacrificial ritual" would be held on the bank of the Minjiang River. That was the earliest form of the water-releasing ceremony. In 978 AD, the Qingming Festival was officially designated as Water-Releasing Festival by the Northern Song Dynasty government.     

In former times, the grand ceremony would be hosted by senior officials in Sichuan. On the eve of the ceremony, those involved in the ceremony would pay homage to Emperor Wang and Emperor Cong at the Wangcong Temple in Pixian County. On the day of water releasing, led by the officiant, a procession carrying offerings accompanied by drum corps would be heading toward the Erwang Temple from the Yulei Pass. At the temple, they would pay tribute to Li Bing and his son. Afterwards, the officiant would chant Deity Welcoming Speech. Then, all people would stand solemnly and sing Song of Commemoration. When the officiant finished the congratulatory speech, he would bow to the sculpture of Li Bing for three times, together with all others, praying for good weather for the crops, good harvests and thriving domestic animals all the year round.

After that, at the order of the officiant followed by three gun salutes, strong workers would cut with full force the ropes tied to the cofferdam blocking the inner river in front of the fish mouth-shaped levee. People on the bench land would strenuously pull the ropes and the cofferdam therefore collapsed, instantly unleashing the river water. At that time, young people would run with the flow and keep throwing stones at the head of the current. This custom was called "hitting the water head". And people would rush to scoop the "head water" and present it to deities as an offering. It was a practice believed to be able to ward off disaster, bring good luck and get blessings from deities.

Currently, the water-releasing ceremony on the Qingming Festival reenacts the long history and folk culture of the agricultural era on the Chengdu Plain, reflecting the good qualities of the Chinese nation in terms of honoring ancient heroes and showing gratitude for their contributions.