Drainage basins of the Black Sea

The Psou (; ; ; ; ) is a river in the West Caucasus, bordering the Gagra Range to the east. It flows along the southern slopes of the Greater Caucasus Mountain Range and forms a part of the border between Georgia (Abkhazia) and Russia. Its source is in the Aigra Mountain, and it flows into the Black Sea. The Psou is long, and the drainage basin is approximately . Between the mouth of the river and the mouth of the Mzymta is a "sandy depositional foreland", which is approximately in length and wide.

drainage basin