The water resources of the region are presented by surface and underground waters. The largest rivers among 17,000 are the Ob, Biya, Katun, Chumysh, Aley and Charysh. Among 13,000 lakes the largest is the Kulundinskoye Lake (728 sq. km.). The main river Ob flows 493 km only within the territory of the region, it is formed by 2 rivers - Biya and Katun - flowing together. The Ob basin takes 70% of the krai territory.
