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
Vytegorsky District Vytegra. Population: 31,757 (2002 Census); The population of Vytegra accounts for 38.6% of the district's total population. The northwestern border of the district is the shore of Lake Onega, and the area of the district is divided between several drainage basins. The western and the central parts belong to the basins of the rivers flowing into Lake Onega, most notably the Vytegra, the Vodla, the Andoma, and the Megra. Lake Onega belongs to the basin of the Neva River. From the east, the Andoma Hills separate the basin of Lake Onega from the basins of the Kovzha and the Kema