It is a tributary of Lake Piros and belongs to the basin of the river Msta.

The source of the Valdayka is in Lake Uzhin within the Valdaysky National Park, close to the town of Valday.

The Moscow – Saint Petersburg Railway crosses the Valdayka close to the village of Lykoshino.

Since the Berezayka flows through the Lake Piros, the Valdayka is considered its tributary.

Media related to Valdayka river at Wikimedia Commons