Lake Onega water per year, of which 46% are industrial and household water, 25% is stormwater runoff and 16% is melioration-related drainage. This drainage contains of phosphorus and of nitrogen; respectively of these elements are removed through the River Svir whereas the rest accumulates in the lake. Ships and motor boats (about 8,000 units) bring oil pollution at the level of about per navigation year, as well as phenols (), lead () and oxides of sulfur, nitrogen, and carbon. The lake basin is a major source of granite, marble and black schist in Russia which have been exploited in the area since
Lake Lacha it includes two of the biggest lakes of Arkhangelsk and Vologda Oblasts, Lake Vozhe and Lake Lyokshmozero. The southern part of the Kenozersky National Park also drains into Lake Lacha. The stretch between Kargopol and the lake is navigable, however, neither the Svid River upstream from the lake nor the Onega River downstream are navigable because of the rapids. There are occasional recreational boat trips from Kargopol to the lake but no passenger or cargo navigation. Several villages are located on or close to the banks, including Morshchikhinskaya, Tobolkino, and Filosofskaya. The latter pair are located on the road connecting