Lake Onega Reservoir has an area of and volume of , i.e. almost the same as those of Onega Lake. Its construction raised the water level of the lake by . The lake contains a well-developed navigation system which is part of the Volga–Baltic Waterway and White Sea – Baltic Canal, connecting the basins of Baltic, Caspian and the northern seas. These canals allow water transport of goods from the lake to the countries from Germany to Iran; most traffic goes to Finland, Sweden, Germany and Denmark. The Onega Canal running along the southern shore of the lake there is not used
Onega, Russia town is also served by the Arkhangelsk–Murmansk rail line, which branches off in Obozerskaya railway station from the railroad between Moscow and Arkhangelsk and runs west to Onega and Belomorsk where it joins the railroad between Petrozavodsk and Murmansk. The railroad was built during World War II to secure the transport of goods from the harbor of Murmansk to central Russia. Onega is connected to Severodvinsk by a road. There are no all-seasonal roads on the left bank of the Onega River. The Onega is navigable downstream from the "selo" of Porog; there is regular passenger navigation. There is also