Sup’ung Dam, hydroelectric project on the Yalu River at the North Korean border with Liaoning province, northeastern China, upstream from Dandong. It was originally designed as a joint project of the Japanese-controlled Manchukuo (Manzhouguo) government, which administered the Northeast (Manchuria) from 1931 to 1945, and the Japanese administration in Korea to supply power for industrial development in Manchuria and northern Korea. Construction was begun in 1937 by the Noguchi conglomerate, which played a large part in developing Korean industry. When completed in 1941, the dam was 525 feet (160 metres) high and 2,790 feet (850 metres) long and formed a vast reservoir (Chinese Shuifeng Shuiku; Korean Sup’ung-ho) 20 miles (30 km) long. By 1944 its operating capacity was 450,000 kilowatt-hours. After Japan’s defeat in 1945, Soviet forces occupied the Northeast, dismantled the Sup’ung generating plant, and transported it to the Soviet Union. The equipment was, however, restored during the first years of Chinese communist rule, and more capacity was added, largely with aid from the Soviet Union and eastern European countries.
The Sup’ung generating plant is linked with the central Northeast grid system, serving the cities of Shenyang (Mukden), Jilin (Kirin), and Harbin, and also with the grid system in the Liaodong Peninsula, supplying Dalian. In addition to its hydroelectric generating capacity, the Sup’ung Dam helps regulate the flow of the Yalu and is also used in irrigation.