|Main source||Greater Caucasus|
|River mouth||Black Sea|
|Length||53 km (33 mi)|
|Basin size||421 square kilometres (163 sq mi)|
Psou River (Georgian: ფსოუ, Abkhazian: Ҧсоу, Russian: Псоу) is a river in the West Caucasus, bordering the Gagra Range of Georgian Region of Abkhazia to the east. It flows along the southern slopes of the Greater Caucasus Mountain Range and forms a part of the border between Georgia and Russia. Its source in the Aigra Mountain, and it flows into the Black Sea. The Psou is 53 kilometres (33 mi) long, and the drainage basin is approximately 421 square kilometres (163 sq mi). Between the mouth of the river and the mouth of the Mzymta River is a "sandy depositional foreland", which is approximately 8 kilometres (5.0 mi) in length and 2 kilometres (1.2 mi) wide.
The principal tributaries of the Psou are the Besh and the Pkhista. Between 1913 and 1955 there was a hydrological station in operation at Leselidze, roughly 1.5 kilometres (0.93 mi) upstream of the river mouth. The Psou gained notoriety as a smuggling route out of the country, by-passing Russian controls on the border. As of 2008 it was still designated as a transboundary river which lacked an international cooperation agreement as part of the UNECE Water Convention.
- Abkhazia is the subject of a territorial dispute between the Republic of Abkhazia and the Republic of Georgia. The Republic of Abkhazia unilaterally declared independence on 23 July 1992, but Georgia continues to claim it as part of its own sovereign territory. Abkhazia has received formal recognition as an independent state from 7 out of 193 United Nations member states, 2 of which have subsequently withdrawn their recognition.
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- Lagutov, Viktor (22 October 2008). Rescue of Sturgeon Species in the Ural River Basin. Springer Science & Business Media. p. 33. ISBN 978-1-4020-8924-4.