Jufeng Weir Irrigation System

The Jufeng Weir Irrigation System is situated in Xiushan County, Chongqing City, within the Yuanjiang River basin, a tributary of the Yangtze River, with the water intake located on the Pingjiang River, a third-level tributary of the Yuanjiang River. Nestled between the Wuling Mountains in a strip-shaped basin, the terrain slopes from higher elevations in the southwest to lower in the northeast, ranging from 350 to 400 meters above sea level. The designated heritage area includes both the Jufeng Weir project site and its entire operational region, primarily encompassing the Qingxichang and Wuyang Sub-districts of Xiushan County, and currently irrigates an area of 800 hectares.
Originally constructed in 1767 of the Qing Dynasty, the Jufeng Weir saw further expansion in 1820 with the addition of the Yongfeng Weir, which provided supplementary water and expanded the irrigation coverage. In 1835, it underwent a significant overhaul that included the construction of three-arch and five-arch aqueducts, increasing the irrigated area to more than 200 hectares. In more recent history, modifications included relocating the Jufeng Weir upstream twice to enhance water diversion in terms of both elevation and volume. In 1958, the Huangjiao Weir was constructed to further augment water diversion to the irrigation canals. The irrigation system features a dam-based water diversion mechanism, with three weirs-Jufeng, Yongfeng, and Huangjiao-built at different times, directing water into two main canals. These irrigation canals traverse two tributaries of the Pingjiang River via three aqueducts, collectively irrigating 800 hectares of agricultural land in the Xiushan basin. The weirs, aqueducts, and other primary structures are constructed of stone masonry. The three-arch aqueduct still retains its original historical form, and the Jufeng Weir continues to feature traditional mortared stone-slab construction. The irrigation network largely preserves its historical configuration.
Aqueducts are a vital component of the Jufeng Weir Irrigation System, key to both expanding the irrigated area and optimizing irrigation efficacy. Among the system's three ancient aqueducts, the three-arch aqueduct is exceptionally well-preserved in its original form. Constructed by at least 1835, this stone masonry structure spans 50 meters in length and rises 12.5 meters in height, with a water channel cross-section measuring 1.1 meters in depth and 2 meters in width. It stands as the oldest and largest of its kind in China still in operation. Unlike this ancient structure, most large stone aqueducts in China were built in the 1950s through the 1970s, and few pre-1949 structures have survived, generally on a smaller scale. The three-arch aqueduct of Jufeng Weir has been impeccably preserved and remains functional to this day, without any signs of foundational subsidence or structural instability. This enduring functionality showcases the advanced design and construction techniques of ancient Chinese large-scale stone aqueduct engineering, highlighting its significant scientific and technological value.
#JufengWeir #Xiushan #Chongqing #PingjiangRiver #icid #whis