The West Sea Barrage is around 15km west of Nampo City. The 8km-long barrage completed in just five years (1981-86) has three locks through which 2,000- to 50,000-ton ships can pass from the West Sea to the Taedong River, as well as a railway, road, and sidewalks across the dam.
The construction of the barrage made it possible to finally solve problems of irrigation to arable areas as well as water supply in industrial and residential areas in the region. In addition, it raised the traffic capacity of ships and facilitated transport in the region.
Before the completion of the barrage, the distance from Nampo to Unryul was 200 kilometers by a roundabout route, but now the traffic line is just 8 kilometers. In addition, the landscape on the lower reaches of the Taedong River was radically improved.