Onega River Onega River The Onega (; ) is a river in Kargopolsky, Plesetsky, and Onezhsky Districts of Arkhangelsk Oblast in Russia. The Onega connects Lake Lacha with the Onega Bay in the White Sea southwest of Arkhangelsk, flowing in the northern direction. The discharge at the source is and at the mouth is . The river is long, and the area of its basin . Its main tributaries are the Voloshka (right), the Kena (left), the Mosha (right), the Kodina (right), and the Kozha (left). The major tributary of the Lake Lacha is the Svid. The name of the river is
Kargopolsky District subordinated to the central administration of Northern Krai. In 1936, the krai was transformed into Northern Oblast. In 1937, Northern Oblast itself was split into Arkhangelsk Oblast and Vologda Oblast. Kargopolsky District remained in Arkhangelsk Oblast ever since. The district is almost exclusively located in the basin of the Onega River, which is the biggest river in the district, and belongs to the basin of the White Sea. The source of the Onega is Lake Lacha, which is the biggest lake in the district. The northeastern shore of Lake Vozhe, also in the basin of the Onega, belongs to Kargopolsky