River Etherow
The River Etherow has no major tributaries but instead is fed by brooks and streams flowing from the cloughs on the moors forming the Dark Peak, such as Kinder Scout, Bleaklow and Black Hill. The Dark Peak forms a watershed of approximately 30 square miles (78 km2), which recieves an annual rainfall of 52.5 inches (1,330 mm).
Longdendale Chain
The Longdendale Chain is six reservoirs on the River Etherow in the valley of Longdendale, in north Derbyshire. Longdendale Chain was constructed between 1848 and 1884 to a design by John Frederick Bateman (30 May 1810 – 10 June 1889), an English civil engineer whose work formed the basis of the modern water supply industry in England, to supply fresh water to the growing population of Manchester.
The reservoirs of Woodhead, Torside, Rhodeswood and Arnfield supply drinking water, and the lower reservoirs, Valehouse and Bottoms, are used to maintain the downstream flow of the River Etherow, known as compensation reservoirs, originally for the benefit of local water-powered mills. The seventh reservoir, Hollingworth Reservoir, was contructed in 1854 but in 1987 was abandoned to become part of the 60-acre (240,000 m2) Swallows Wood nature reserve which contains semi-natural woodlands, meadows, ponds and marsh areas.
Water from the Longdendale Chain flows into an aqueduct connecting to the Arnfield reservoir from where the water passes by gravity along the Mottram Tunnel to the Godley reservoir on the edge of Manchester.
The Mottram Tunnel was built between August 1848 and October 1850, and the Godley service reservoir was built to receive and filter the water in 1851.The Mottram Tunnel is 3100 yards long, and has a fall of 5 feet in one mile. The Mottram Tunnel is lined in stone, it is 6 feet in diameter and can carry 50,000,000 gallons a fresh drinking water per day.
Godley Reservoir
At Godley Reservoir the water was originally filtered by passing it through straining frames made of oak and fine wires. It was chlorinated to remove bacteria and then entered Manchester's water distribution network. In the 1960s additional treatment works were built at Arnfield and Godley. From Godley water also flows by gravity to the service reservoirs at Denton, Audenshaw, Gorton and Prestwich.
Pipes and Tapes
