Lake Lacha Lake Lacha Lake Lacha () is a freshwater lake, located in the south of Kargopolsky District of Arkhangelsk Oblast in Russia, south of the town of Kargopol. It is the largest lake in Arkhangelsk Oblast, with a surface area of and a basin area of . Lake Lacha is the source of the Onega River, one of the major waterways of the White Sea basin. The etymological origin of the name is unclear. The river basin of Lake Lacha includes the southern and western parts of Kargopolsky District of Arkhangelsk Oblast, as well as north-west of Vologda Oblast. In particular,
Onega River mid-April - May. It was used for timber rafting. The Onega flows among the coniferous forests (taiga of spruce, pine, and larch), mostly among the swamps. There are only four bridges across the Onega: one in Kargopol on the road connecting Kargopol to Nyandoma, one in the village of Sorokinskaya, on "Onezhsky Trakt", the road connecting Kargopol to Plesetsk and Yemetsk, one combined road and railway bridge connecting Oksovsky and Severoonezhsk, and one railway bridge in Porog on the railway from Arkhangelsk to Belomorsk (no road traffic). Elsewhere, including the former district center of Konyovo, the Onega can only be