The lower part of the estuary bank is influenced by the tides, and the left bank within the jurisdiction of Gunsan City serves as a residential area, where a lot of sand dunes and tidal flats are formed by flux and reflux. The place under the estuary bank has a tidal flat and a field of reeds formed by a meandering stream, which is good for the seasonal birds to live in. Especially the tidal flat around islands during the ebb tide is important to the seasonal birds.

- Observable birds£ºSnipe, Plover, Common shelduck