a river in Komi-Permiak National Okrug, Perm’ Oblast, RSFSR, a right tributary of the Kama River. Length, 267 km; basin area, 10,300 sq km. It originates in the northern Verkhnekamskaia Highlands and flows through swampy lowlands. The river is fed mainly by snow, and its average flow rate at a point 43 km from its mouth is approximately 40 cu m per sec. The Kosa freezes over in late October and November and opens again in April and early May. Timber is floated down the river.