Lake Undozero Lake Undozero Lake Undozero () is a freshwater lake, located in the west of Plesetsky District of Arkhangelsk Oblast in Russia. It is one of the biggest lakes in Arkhangelsk Oblast and the second biggest one in Plesetsky District. The area of the lake is , and the area of its basin is . Lake Undozero is the source of the Undosha River, which belongs to the river basin the Onega River and thus to the White Sea basin. The lake has a sophisticated shape and contains a number of islands. The source of the Undosha is in the south-western
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