Cut-off Channel

Cut-off Channel
The Cut-off Channel near Feltwell
Location
Country	England
Counties	Norfolk, Suffolk
Physical characteristics
Source
• location	Mildenhall, Suffolk
Mouth	Denver Sluice
• location	Denver, Norfolk
Length	28 mi (45 km)

v t e Cut-off Channel
Legend
Great Ouse and Relief Channel Salters Lode Lock Old Bedford Sluice A G Wright Sluice Denver Sluice (lock) Relief Channel Lock River Great Ouse Bedford Rivers Great Ouse to Ely King's Lynn to Ely Railway A10 Pumping station Pumping station B1160 College Road Wretton Fen Road Cut-off sluice River Wissey Thornham Road Severalls Road, Methwold Hythe Little Oulsham Drove Southay Road, Feltwell Blackdyke Intake (to Essex) B1112, Hockwold cum Wilton Pipeline to Kennett pumping station Cut-off sluice River Little Ouse Lakenheath railway station B1112 Station Road Willow Grove Highbridge Gravel Drove Undley Road, Lakenheath Eriswell Road A1065 Mildenhall Woods Thetford Road A11 A1101 Sluice River Lark at Barton Mills

The Cut-off Channel is a man-made waterway which runs along the eastern edge of the Fens in Norfolk and Suffolk, England. It was constructed in the 1950s and 1960s as part of flood defence measures, and carries the headwaters of the River Wissey, River Lark and River Little Ouse in times of flood, delivering them to Denver Sluice on the River Great Ouse. In the summer months, it is also used as part of a water supply scheme for drinking water in Essex.

The scheme was first suggested by the drainage engineer Cornelius Vermuyden in 1639, but was not pursued at the time, probably because of the cost. It was again suggested by John Rennie in 1810, but again the cost was prohibitive. Flooding events in 1937 and 1939 caused the newly formed Great Ouse Catchment Board to resurrect the plan, and disastrous floods in 1947 resulted in construction starting in 1954, as part of a bigger scheme to address the issues faced by communities living near to the Great Ouse. in 1968, water companies in Essex developed a plan to transfer drinking water from the Great Ouse to reservoirs at Abberton and Hanningfield. The scheme was completed in 1971, and results in water flowing in the reverse direction along the Cut-off Channel, from Denver to an intake at Blackdyke, from where tunnels, pipelines and rivers convey it to Essex.

Over its 28-mile (45 km) length, the channel passes through a variety of soil types, and this provides several types of habitat. Surveys in 1997 and 1998 revealed that the depressed river mussel had colonised the waterway. In order to meet the requirements of the Water Framework Directive, a syphon fish pass was constructed between the Channel and the River Wissey in 2013, to prevent fish becoming trapped in the Channel, with no access to suitable habitat or other waterways.