Lopan River [Lopan’]. (Map: Lopan River.) A left-bank tributary of the Udy River (which it joins at Kharkiv). It is 96 km long (78 km in Ukraine) and drains a basin area of 2,000 sq km. The Lopan flows through the Central Upland within the borders of Belgorod oblast (Russian Federation) and Kharkiv oblast. Its waters are used for industrial and domestic consumption. The main cities located along the river are Kharkiv and Derhachi.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 3 (1993).]