Xifei River

Xifei River

The Xifei River lies between the drainage basins of the Ying, Wo, Qian, and Nihei rivers. It originates from Machangji in Taikang County, Henan Province, flows through six counties in Anhui—Bozhou, Taihe, Lixin, Woyang, Yingshang, and Fengtai—and empties into the Huai River at Xiashankou in Fengtai, stretching 250 kilometers in length with a drainage area of 4,750 square kilometers, situated in a plain region. The 1951 source interception project blocked the Wanghekou, diverting the upstream water (from the Qingshui River) eastward via the You River and the Ming River into the Wo River, reducing the drainage area to 3,550 square kilometers. The waters of the Wu River and Sanchagou were further reduced by 350 square kilometers after the construction of the Wuhe Culvert and Changlin Culvert, which sealed the channel of the Tongji River. Following these diversions, the actual drainage area of the Xifei River was reduced to 3,200 square kilometers. In 1958, the excavation of the Sugou and Jihex rivers redirected 654 square kilometers of water originally belonging to the right bank of the Ying River basin to drain into the Xifei River. From then on, the drainage area of the Xifei River became 3,854 square kilometers.

The current Xifei River originates from Feiheji, flowing southeast along the border between Taihe County and Bozhou County, passing west of Longde and Yangdian, and after reaching Gaogongmiao, it follows the boundary between Taihe County and Woyang County, entering the territory of Lixin County north of Miaoji. It continues to flow southeast, passing Simiao, Zhujix, and Wangshicheng, crosses the Suifu Railway bridge east of Jizhen, then flows through Shuanggou, Kantuan, and Zhangu, along the border between Yingshang County and Fengtai County, and enters Fengtai County near Miyao. Downstream of Jinluji, it expands into Jigou Lake, and north of Maojiaji, it is also called Maojia Lake. North of Jiangzuizi, it turns northward and joins the Huai River downstream of Xiashankou.

In 1971, the new Cihuai River was excavated, and in 1976, the Xifei River was cut off at Kantuanji. The section above Kantuanji is referred to as the upper Xifei River, which drains directly into the Cihuai River and is now part of the Cihuai River system. The river channel stretches 99 kilometers from Feiheji to Kantuan, with a drainage area of 2,244 square kilometers, of which 1,871 square kilometers come from the main stream above Liuyingzi, and 373 square kilometers from tributaries such as the Ganghe and Baiyanggou. At Zhujix, the Zhujix River Control Dam was built. Below the dam and up to Liuyingzi (the Cihuai River inlet), the riverbed is 61–115 meters wide, with a bed elevation of 21.70–18.98 meters. The drainage capacity for floodwater is 409–603 cubic meters per second, with a water depth of 6.0–7.0 meters, a drainage gradient of 1/23,000, a flood gradient of 1/26,500, a water depth of 8.0–8.5 meters. Above the dam, up to Luoji, the riverbed is 56–16 meters wide, with a bed elevation of 22.35–30.10 meters. The drainage capacity for floodwater is 369–26 cubic meters per second, with a water depth of 5.5–3.5 meters, a drainage gradient of 1/13,000, a flood gradient of 1/10,000, and a water depth of 7.0–6.0 meters. The maximum flow recorded at Wangshicheng was 454 cubic meters per second (June 9, 1963), while the lowest flow resulted in the river running dry (occurred in 1956, 1958–1961, and 1966–1970). The highest water level was 28.28 meters (July 21, 1954), and the lowest was when the river ran dry, exposing the riverbed.

The section below Kantuanji is called the lower Xifei River, extending 64 kilometers from Kantuan to the river mouth, with a drainage area of 1,609 square kilometers. The river channel is winding, and the terrain is low-lying. After the old river channel was silted up by the Yellow River floods, dredging was carried out in 1951. A new river channel was excavated along the right bank, and during high water, the new river, old river, and lowlands merge into one, with a water surface width of 3–4 kilometers. Since 1965, 43 polders have been built along both banks of the lowlands, protecting approximately 200,000 mu of land. The current drainage capacity reaches 675–950 cubic meters per second, meeting the standard for a 10-year flood event. The riverbed elevation is 17.4–14.0 meters, the riverbed width is 50–42 meters, the water depth is 6.9–9.0 meters, and the gradient is 1/31,000. During the flood season, when the Huai River water level is high, the Xifei River Dam at the river mouth is closed to prevent backflow. If internal water levels are also high, most of the polder dikes must be breached to retain the internal water. Major tributaries on the right bank include the Jihex River, with a catchment area of 726 square kilometers, and the Sugou River, with a catchment area of 269 square kilometers. On the left bank are the Ganghe River, with a catchment area of 208 square kilometers. The highest water level recorded at the Xifei River Dam was 24.82 meters (July 29, 1954), and the lowest was 14.22 meters (June 21, 1953). The lowest water level downstream of the dam was 25.38 meters (July 27, 1954), and the lowest was 13.96 meters (July 3, 1958).