Unbong Dam

The Unbong Dam, or Yunfeng Dam, is a concrete gravity dam on the Yalu River which borders China and North Korea. It is located 33 km northeast of Ji'an in Jilin Province, China and Chasŏng in Chagang Province, North Korea. The primary purpose of the dam is hydroelectric power generation and it supports a 400 MW power station. Construction of the dam had initially began in August 1942 but was halted in 1945 after the surrender of Japan ending World War II. In October 1959, construction on the dam recommenced and in September 1965, the first of the four 100 MW Francis turbine-generators was operational. The last generator was operational on 4 April 1967. The 113.75 m tall dam creates a reservoir with a storage capacity of 3895000000 m3. The dam's spillway is an overflow type with 21 floodgates and has a maximum discharge of 21900 m3/s. The dam is located before a bend in the river and its power station is located on the other side of a ridge that meets the dam's right abutment. Water is delivered to the power station via two tunnels, 775 m and 759 m long. Generators 1 and 3 deliver power to China while 2 and 4 deliver to North Korea.