Stausee Ferden
Canton of Valais, Switzerland
Stausee Ferden ("Ferden reservoir") is a reservoir on the Lonza river at Ferden, Valais, Switzerland. Its surface area is 10.6 ha (26 acres). Its construction was completed in 9 June 1976. The lake has the shortest lake retention time in the world.
Reservoir data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).