Located in Mentougou District, Beijing, in the upper reaches of the Yongding River Basin, the Mentougou Ancient Canals consists of five key ancient irrigation canals—Gongyigou, Sanjiadian, Dingjiatan, Chenglong, and Fujiatai—along with surrounding ancient springs and wells. As the first World Heritage Irrigation Structure in the Beijing‑Tianjin‑Hebei region, it serves multiple functions, including irrigation, flood control, and ecological water replenishment.

In response to the Yongding River’s characteristics, namely its high sediment load and frequent silting and flooding, ancient engineers developed unique techniques like “water diversion without dams, weir-controlled sediment regulation” and “counter-slope water supply, forward-slope sediment discharge”. Through stepped elevation differences, the main, branch, and field channels are arranged with gradually rising beds, forming a reverse slope. This slows water flow, allowing sediment to settle naturally in the upstream main channels and effectively preventing siltation in the downstream sections. When channels are drained, accumulated sediment is flushed and drained back into the Yongding River. Additionally, the canals were used to divert sediment-laden water into riverside lands, where repeated cycles of irrigation, sedimentation, and drainage achieved the remarkable feat of “sediment-laden irrigation for land reclamation.”

The Mentougou Ancient Canals of Yongding River dates back to AD 250 during the Three Kingdoms period. At its height, it irrigated a vast 4,400 hectares. The main channel of the Gongyigou Canal stretches about 6 km. Initially constructed for water supply and drainage of the Longquanwu kilns during the Liao and Jin dynasties, it later evolved into an irrigation channel. Sections within Longquanwu Village remain in use today, largely preserving their century‑old form and appearance. The Dingjiatan Canal has remained in operation since1949, irrigating farmland and orchards in Dingjiatan Village and providing solid support for local agricultural production. The Fujiatai Canal was built by local villagers through a self-organized fundraising effort. In the late 1950s, during the construction of the Zhuwo Reservoir, a concrete diversion dam was built at the canal’s intake to ensure its water supply. In the late 1960s, the downstream 400-meter section was lined to prevent seepage. Later reinforcements using stone masonry helped preserve the original channel structure, allowing it to remain stable and operational to this day.

The Gongyigou Canal

Beyond its outstanding engineering, this irrigation system also featured forward-looking management models. Starting in the Qing Dynasty, the Sanjiadian Canal established the Minsheng Water User Association, Beijing’s earliest farmer-led water user association. It developed water‑use rules and maintenance systems, democratically electing managers, managing funds, and mediating disputes to ensure the long‑term operation of the project.

The Fujiatai Irrigation Canal

With urban development, the Sanjiadian and Chenglong Canals no longer serve irrigation purposes. The Sanjiadian Canal now functions as a drainage channel for flood control. The Chenglong Canal serves as the core water vein of the “Six-Water Interconnection” project, contributing to the revival of numerous springs. Currently, the system irrigates about 133 hectares of farmland and supplies water to orchards and ecological areas covering around 1,333 hectares. In 2025, it was successfully inscribed on the World Heritage Irrigation Structures list.

Source: INTCE