The river is fed by underground waters and atmospheric condensation. The rivers that flow into it are the Oskol (the biggest of its tributaries), the Udy, the Lopan, the Kharkov, the Mzha.

In the West part of the region the biggest rivers are the Merla, the Kolomak, the Orel, the Berestovaya, the Samara, which belong with the Dnieper watercourse.

Considerable water resources are stored in lakes. The biggest lakes are the Liman, the Chaika, the Svetlichnoye, the Kamyshevatoye. Besides that, two large artificial reservoirs were created in the Sversky Donets watercourse - the Pechenezhskoye and the Krasnooskolskoye reservoirs.

The richest in water resources are the north-west, the north-east, and the central parts of the region. In the main, this is where the biggest forests are situated. In the south parts, forests are scattered in small patches along washes, ravines, lowlands.