The Myponga Reservoir is a reservoir in South Australia, located about 60 km south of Adelaide near the town of Myponga. The reservoir is fed by the Myponga River and other rivers in the Myponga catchment. It provides about 5% of the City of Adelaide's water supply and is the main source of filtered water for southern metropolitan Adelaide and the southern coast area. Plans to utilise the Myponga River catchment as a major storage area were made in 1945. Construction began in 1957 and was completed in 1962, flooding what was from 1840 known as "Lovely Valley".