HUAI RIVER

Chinese (Wade-Giles) Huai Ho, or (Pinyin) Huai He, also spelled Hwai Ho, river in North China that drains the North China Plain between the Huang Ho (Yellow River) and the Yangtze River. The river has a length of 660 miles (1,100 km) and drains an area of 67,000 square miles (174,000 square km). It is fed by numerous tributary streams rising in the Fu-niu, the T'ung-pai, and the Ta-pieh mountains, which, with their extensions into Anhwei province north of the Yangtze, form its southern watershed. The Huai River flows eastward to discharge into Hung-tse Lake in Kiangsu province. In ancient times this lake was much smaller than at present, and the Huai River discharged from it into the sea roughly on the line of the modern Kuan River, south of Lien-yn-kang. The river's mouth was, however, blocked by silt, and so the water from Hung-tse Lake drained away through the string of lakes in eastern Kiangsu into the Yangtze River near Yang-chou. In the north a series of tributaries flows northwest to southeast from a very low watershed almost on the southern dikes of the Huang Ho. From time to time the Huang Ho has flowed through the north of the Huai drainage basin and has discharged into the Huai or even, on occasion, first into the Huai and then into the Yangtze. The drainage of this flat and featureless plain has been a perennial problem, particularly since the 1850s, when the Huang Ho, which had previously discharged into the sea at Hai-chou Bay, again coursed north of the Shantung Peninsula. As a result, much of the drainage into its lower course was diverted into the Huai River, leading to continual flooding. In the 1930s part of the Huai River system was dredged, and an artificial channel protected by flood barrages was cut from the Hung-tse to the sea. During the Sino-Japanese War, the Chinese army, in an attempt to block the Japanese southward advance through the North China Plain, blew up the dikes of the Huang Ho near Cheng-chou in 1938, flooding a large area in Honan province. Extensive work to control the Huai River took place after World War II. The dikes were repaired, and the Huang Ho returned to its old course through northern Shantung. In 1951 work began on a comprehensive water-conservancy project for the Huai River basin. The Su-pei Canal (q.v.), the outlet canal from Hung-tse Lake to the sea, was reconstructed, and an alternative outlet to the sea was also completed. At the same time, the repair and improvement of the Grand Canal (q.v.) also bettered the drainage of Hung-tse Lake to the south. In the early 1950s the headwaters of the Huai and its western tributaries in the Fu-niu and T'ung-pai mountain ranges were controlled by construction of many large retention dams. In 1957 a second stage of flood control began on the southern tributaries. After 1958 the area south of the Huai was incorporated into a large coordinated irrigation system. In the late 1960s government attention shifted to work on the New Pien Canal north of the Huai, although development in the south still continued. By the early 1970s the Huai's northern tributaries had been joined to the New Pien Canal, which provided more effective flood control in the northern Huai plain. In the early 1980s the Huai River was navigable by small ships above Huai-nan, while the Su-pei Canal provided a navigable outlet to the sea. River traffic from the Huai could also join the Grand Canal, providing a water transport route north to the Huang Ho and south to the Yangtze River.