Frankley Reservoir is a semi-circular reservoir for drinking water in Birmingham, England. Its construction was authorised by the Birmingham Corporation Water Act of 1892. It was built by Birmingham Corporation Water Department to designs by Abram Kellett of Ealing in 1904. It contains 900,000 cubic metres (200,000,000 imp gal) of water received from the Elan Valley Reservoirs, 73 mi (117 km) away, in Wales, which arrives via the Elan aqueduct, by the power of gravity alone, dropping 171 feet (52 m) - an average gradient of 1 in 2,300. Before 1987 it was leaking 540 litres (120 imp gal) per second. In that year Ground-penetrating radar was used successfully to isolate the leaks.
