Built between 1960 and 1965, the regulating reservoir of Llyn Celyn was constructed as part of the Bala Lake Scheme in the River Dee catchment area to provide a constant supply of water for the City of Liverpool. An area of some 320ha was submerged under 81million cubic metres of water and the village of Capel Celyn and twelve farms were drowned by the reservoir, causing a great controversy at the time which still lingers today (see 'Cofiwch Dryweryn' wall, near Aberystwyth, nprn 305925).
Unusually for a reservoir intended for water supply, it also generates 4MW of electricity for the national grid.
RCAHMW, February 2011.