Garreg Ddu Dam
Historic reservoir photographs and the submerged landscape around Garreg Ddu.
The history of Garreg Ddu Dam
Garreg Ddu Dam, also known as the submerged dam, is the second of the Elan Valley dams.
The completely submerged dam plays a vital role in maintaining a constant supply of water to Birmingham.
Garreg Ddu holds water back on the upstream side so that water can always be extracted at the Foel Tower.
Height of weir – 82 ft above river bed
Total capacity – 4,585 million gallons
Height – 123 ft above river bed
Length – 417 ft 6 in.
Total capacity – 1,320,000,000 gallons
Garreg Ddu during the summer of 2022
Garreg Ddu during the summer of 2018
Garreg Ddu during 1936
Photos courtesy of Ann Lloyd, Rhayader.
Garreg Ddu during the drought of 1975
Photo courtesy of Rob Davies, Rhayader.
Garreg Ddu before the dams were built
Photo courtesy of Mrs Pauline Walton, Rhayader.
Garreg Ddu before the dams were built
Photo courtesy of Mrs Syd Meredith, Newbridge-On-Wye.
