The River Daugava (in Latvian) or Western Dvina (Russian: Западная Двина́ (Zapadnaya Dvina); Belarusian: Заходняя Дзвіна, [zaˈxodnʲaja dzʲvʲiˈna], traditionally Дзвiна, Dzvina; German: Düna), not to be confused with Northern Dvina, is a river rising in the Valdai Hills, Russia, flowing through Russia, Belarus, and Latvia, draining into the Gulf of Riga in Latvia, an arm of the Baltic Sea. The total length of the river is 1,005 km (624 mi): 325 km (202 mi) in Russia, 328 km (204 mi) in Belarus, and 352 km (219 mi) in Latvia. In the 19th century, it was connected by a canal to the Berezina and Dnieper rivers (the canal is currently not functioning). The Daugava forms part of the international border between Latvia and Belarus.
According to C.Michael Hogan, the Daugava River began experiencing environmental deterioration in the era of Soviet collective agriculture (producing considerable adverse water pollution runoff) and a wave of hydroelectric power projects.