Yangeuidae is a 12km long and 3㎢ riverine wetland developed in the mainstream of the Bukhangang River at the Civilian Control Line in Hwacheon-eup, Hwacheon-gun. Starting from the Peace Dam, it stretches along the river through Andong Steel Bridge to Ojakgyo Bridge at the South Limit Line of North Korea. The Yangeuidae has been formed around point bars in meanders over years. The point bars are crescent-shaped bars made of sand or gravels deposited on slip-off slopes -opposite undercut slopes. Its formation was attributed to the stabilization of the deposits in the meanders. However, its growth was affected by changes in water level caused by the constructions of Peace Dam (Dong-ri, Hwacheon-eup, Hwacheon-gun, Gangwon Province) and Imnam Dam (Imnam-myeon, Changdo-gun, Northern Gangwon Province). The Peace Dam was built in 1989 upstream Lake Paroho to defend against a flood attack from Imnam Dam of North Korea whose construction started in 1986. Since the dam has no particular sluice gates, it lets water drain through four 10m diameter drain holes, so normally it cannot hold water in it. Such a characteristic of the dam caused frequent small changes in water level, thereby accelerating the development of the wetland nearby. The area of the wetland has begun to expand as water level in the river dropped due to the Imnam Dam which was completed in 2003; the dam caused the water once used for hydro-electric power generation to drain to the East Sea coast rather than to the basin of the Bukhangang.