Udy River (also Uda). (Map: Udy River.) A right-bank tributary of the Donets River that flows for 164 km through Belgorod oblast (Russian Federation) and Kharkiv oblast and drains a basin area of 3,893 sq km. Its source is in the Central Upland, and it is fed by rain and meltwater. The river is used for irrigation and for water supply. The city of Kharkiv is situated at the point where the Lopan River empties into the Udy River.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 5 (1993).]