bartley reservoir
Bartley Reservoir stores 500M gallons of Elan Valley drinking water stored up to 60ft deep over 125 acres. As the water goes from here to the Frankley Treatment Works, the reservoir can be used for leisure activities.
It was built 1925-30 after it was recognised that the much smaller Frankley Reservoir at the terminus of the Elan Aquaduct couldn't store enough water for the city's needs.
See multimap here.