Tongji Weir

　　Guide: Tongji Weir is a water conservancy project primarily designed for irrigation and also capable of water storage and drainage. It consists of a water-retaining dam, inlet sluices, the Three-Arch Bridge, channels, and leaf-shaped outlets. The Bihu Plain has a terrain that slopes from southwest to northeast with a drop of 20 meters. Tongji Weir was constructed based on this geographical feature, thereby achieving largely gravity-fed irrigation without the need for external power. The weir collects water from an upstream catchment area of 2,150 square kilometers, intercepting over 200,000 cubic meters of water into its channels daily, irrigating more than 40,000 acres of farmland across the central and southern parts of the Bihu Plain. According to villagers, the Zhuge family, a lineage known for protecting the weir, have lived near Tongji Weir for generations and would step in to stop any destructive behavior such as blocking channels or cutting trees. During maintenance work in the 1950s, massive ancient pine foundations, known as the “sleeping ox” method of pine timber padding, were discovered at the base of the dam.

　　Tongji Weir is located near a small village called Yantou on the Bihu Plain in southern Zhejiang. Built in the fourth year of the Tianjian era during the Liang Dynasty of the Southern Dynasties (505 AD), it has a history of 1,500 years. It is the oldest large-scale water conservancy project in China and also the earliest known arch dam in the world. It is a national key cultural relics protection unit.

　　History: The name “Tongji Weir” dates back to the eighth year of the Shaoxing era in the Southern Song Dynasty (1138 AD). According to Shen Guochen’s Record of Tongji Weir: “After the Southern Crossing, Zhao Xuelao from Wenshang, who was appointed magistrate of the county, greatly admired the benefits this weir brought to the people and bestowed upon it the name ‘Tongji’ to praise its virtues…” Historical records indicate that Fan Chengda (of the Song Dynasty) served in various positions in Chuzhou between 1126 and 1193. In the fourth year of the Qiandao era of the Southern Song Dynasty (1168 AD), Fan Chengda oversaw the renovation of Tongji Weir and personally formulated and wrote the Weir Regulations, which were inscribed on a stele. “The text is concise and the calligraphy rivals that of Su Shi and Huang Tingjian,” with the original handwriting still preserved. He led the repair work for three months, restoring Tongji Weir, and inscribed twenty articles of the Tongji Weir Stele in fourteen lines to inform future generations. These Weir Regulations have been in use for hundreds of years.

　　Address: Beside Yantou Village, Bihu Town, Duilian District, Lishui City

　　Type: Historic Water Conservancy Project

　　Recommended Visit Duration: 1–2 hours

　　Opening Hours:

　　Open all day

　　Ticket Information:

　　No admission fee.