 The reservoir was transferred to Welsh Water in 1973 when the Welsh Water Authority was formed, and it supplied water until the mid-1970s.In 1996 Welsh Water's holding company was renamed as Hyder plc and the group acquired South Wales Electricity plc.After Hyder's share price collapsed in 1999 and 2000, the Hyder Group was sold to WPD on terms recommended by the Hyder Board after a competitive and hostile takeover battle.