The Mottram Tunnel is a tunnel carrying drinking water by gravity from Arnfield Reservoir

Arnfield Reservoir

Arnfield Reservoir is a man-made lake in Longdendale in north Derbyshire. It was constructed in 1854 as part of the Longdendale chain to supply water from the River Etherow to the urban areas of Greater Manchester. Unlike the other reservoirs in the chain, Arnfield and Hollingworth Reservoir are...

, Tintwistle

Tintwistle

Tintwistle is a village and civil parish in the High Peak district of the non-metropolitan county of Derbyshire, England. According to the 2001 census the parish had a population of 1,401. The village is just north of Glossop at the lower end of Longdendale Valley...

, Derbyshire

Derbyshire

Derbyshire is a county in the East Midlands of England. A substantial portion of the Peak District National Park lies within Derbyshire. The northern part of Derbyshire overlaps with the Pennines, a famous chain of hills and mountains. The county contains within its boundary of approx...

 in the valley of the River Etherow

River Etherow

The River Etherow is a river in northern England, and a tributary of the River Goyt. Although now passing through South Yorkshire, Derbyshire and Greater Manchester, it historically formed the ancient county boundary between Cheshire and Derbyshire. The upper valley is known as Longdendale...

, to Godley, Greater Manchester

Greater Manchester

Greater Manchester is a metropolitan county in North West England, with a population of 2.6 million. It encompasses one of the largest metropolitan areas in the United Kingdom and comprises ten metropolitan boroughs: Bolton, Bury, Oldham, Rochdale, Stockport, Tameside, Trafford, Wigan, and the...

 in the valley of the River Tame

River Tame, Greater Manchester

The River Tame flows through Greater Manchester, England.-Source:The Tame rises on Denshaw Moor in Greater Manchester, close to the border with West Yorkshire but within the historic West Riding of Yorkshire.-Course:...

. It was essential to the construction of the Longdendale Chain

Longdendale Chain

The Longdendale Chain is a sequence of six reservoirs on the River Etherow in the valley of Longdendale, in northern Derbyshire. They were constructed between 1848 and 1884 to a design by John Frederick Bateman to supply the growing population of Manchester and Salford with fresh water.The top...

 of reservoirs constructed by John Frederick Bateman

John Frederick Bateman

John Frederick Bateman was an English civil engineer whose work formed the basis of the modern United Kingdom water supply industry. For over 50 years from 1835 he designed and constructed reservoirs and waterworks. His largest project was the system that supplied Manchester with much of its...

. The tunnel was built between August 1848 and October 1850, and the Godley service reservoir

Godley Reservoir

The Godley Reservoir is a reservoir in Hyde, Greater Manchester in England. It was completed in 1851, as a critical part of the Longdendale Chain project that brought fresh water to Manchester....

 was built to receive and filter the water. That was finished in 1851.

The Manchester Corporation Waterworks Act 1847 gave permission for the construction of the Woodhead

Woodhead Reservoir

Woodhead reservoir is a man-made lake near the hamlet of Woodhead in Longdendale in north Derbyshire. It was constructed by John Frederick Bateman between 1847 and June 1877 as part of the Longdendale chain to supply water from the River Etherow to the urban areas of Greater Manchester...

, Hollingworth

Hollingworth Reservoir

Hollingworth Reservoir is a former reservoir near Hollingworth, north Derbyshire. It was constructed in 1854 as part of the Longdendale Chain, but was abandoned in 1987 and now forms part of the Swallows Wood nature reserve.- See also :...

 and Arnfield reservoirs, and the construction of a masonry aqueduct to convey drinking water from the Arnfield and Hollingworth reservoirs to a service reservoir at Godley. Manchester Corporation Waterworks Act 1848 allowed the construction of Torside

Torside Reservoir

Torside Reservoir is the largest man-made lake in Longdendale in north Derbyshire. It was constructed by John Frederick Bateman between April 1849 and July 1864 as part of the Longdendale chain to supply water from the River Etherow to the urban areas of Greater Manchester.The Manchester...

 and Rhodeswood

Rhodeswood Reservoir

Rhodeswood Reservoir is a man-made lake in Longdendale in north Derbyshire. It was constructed by John Frederick Bateman between 1849 and June 1855 as part of the Longdendale chain to supply water from the River Etherow to the urban areas of Greater Manchester...

reservoirs, and an aqueduct to convey the water to the Arnfield reservoir.

The tunnel pierces the ridge that lies between the Etherow valley and the Tame valley. It is 3100 yards (2,834.6 m) long, and has a fall of 5 feet (1.5 m) in one mile. It is lined in stone, is 6 feet (1.8 m) in diameter and can carry 50,000,000 gallons a day.