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
Lake Onega Lake Onega has a surface area of without islands and a volume of ; its length is about and width about . It is the second largest lake in Europe, and the 18th largest lake by area in the world. Its southern banks are mostly low and continuous, whereas northern banks are rocky and rugged. They contain numerous elongated bays shaping the lake into a giant crayfish. In the northern part lies a large Zaonezhye Peninsula (); south of it, is the Big Klimenetsky () island. To the west of them lies the deep (deeper than ) Greater Onega ()