Lago Ritom
Canton of Ticino, Switzerland
Lago Ritom is a lake in the Piora valley, Ticino, Switzerland. The natural lake is used as a reservoir by the Swiss Federal Railways (SBB-CFF-FFS) to generate hydro-electric power for the Gotthard line. The first dam was built in 1918 and, in 1950, its height was increased by 23 m.
Reservoir data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).