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 Kovzhskoye complex shape, with one bay in the south and one more bay (Lake Lozskoye, where the source of the Kovzha is located) in the southwest. From the north, Lake Kuzhozero is adjacent to Lake Kovzhskoye. The catchment area of Lake Kovzhskoye is relatively small, since the lake is located in the Andoma Hills. To the east of the lake, there is river basin of the Kema River, another tributary of Lake Beloye, and the areas to the north and to the west drain into Lake Onega. Two villages, Loza and Yakshino, are located on the southern shore of the lake.