River Lee Flood Relief Channel, Newmans Sluices - geograph

The Lee Flood Relief Channel (FRC) is located in the Lea Valley and flows between

Ware, Hertfordshire Ware is a town in Hertfordshire, England close to the county town of Hertford. It is also a civil parishes in England, civil parish in East Hertfordshire district. Location The town lies on the north–south A10 road (Great Britain), A10 road ...

, and Stratford, east London. Work started on the channel in

1947 It was the first year of the Cold War, which would last until 1991, ending with the dissolution of the Soviet Union. Events January * January–February – Winter of 1946–47 in the United Kingdom: The worst snowfall in the country in ...

following major flooding and it was fully operational by 1976. The channel incorporates existing watercourses, lakes, and new channels. Water from the channel feeds the Lee Valley Reservoir Chain.

Design

Flood defences are rated according to the probability that a particular level of flood water will be exceeded at least once in a specific period, so a

100-year flood A 100-year flood is a flood event that has a 1 in 100 chance (1% probability) of being equaled or exceeded in any given year. The 100-year flood is also referred to as the 1% flood, since its annual exceedance probability is 1%.Holmes, R.R., Jr. ...

represents a level that would only be expected to occur once in 100 years. This is often known as 1 per cent protection. The level of flooding in 1947 was estimated to be a 1.4 per cent occurrence, and the flood channel, when it was first designed, was built to cope with this level of flooding. Since it was completed in 1976, there have been no major flood events in the Lea Valley, although there have been three occasions when the river system was full virtually to its capacity: in 1987, 1993 and 2000. Since its completion, the level of protection afforded by the structure has declined, so that in some areas it offers 2 per cent protection, and in some, only 5 per cent protection. The

Environment Agency The Environment Agency (EA) is a non-departmental public body, established in 1996 and sponsored by the United Kingdom government's Department for Environment, Food and Rural Affairs, with responsibilities relating to the protection and enha ...

published a strategic environmental assessment in 2008, which looked at ways to maintain the flood defences in the Lea Valley.

Course

Hertfordshire and Essex

Marking the start of the FRC at Ware, the channel is incorporated into the

Lee Navigation The Lee Navigation is a canalised river incorporating the River Lea (also called the River Lee along the sections that are navigable). It flows from Hertford Castle Weir to the River Thames at Bow Creek; its first lock is Hertford Lock and its ...

. It flows through

Hardmead Lock Hardmead Lock (No3) is a lock on the River Lee Navigation at Great Amwell close to the town of Ware. The lock has a reputation as being difficult to negotiate. Location The lock-keeper's cottage stands on an island formed by a section of th ...

and

Stanstead Lock Stanstead Lock (No4) is a lock on the River Lee Navigation close to the villages of Stanstead Abbotts and St Margarets. The lock which incorporates a rare example of a swing-bridge, has the reputation of being one of the country's most difficul ...

, which have had automatic

sluice Sluice ( ) is a word for a channel controlled at its head by a movable gate which is called a sluice gate. A sluice gate is traditionally a wood or metal barrier sliding in grooves that are set in the sides of the waterway and can be considered ...

gates installed to cope with high water levels. At Feildes Weir a parallel channel has been constructed. The channel then skirts the Glen Faba Lake and passes under Dobbs Weir Road before entering the North Lagoon of the Nazeing Meads lake complex and leaving at the South Lagoon at Nazeing Weir. Continuing under Nazeing Road ( B194), the channel flows through the

River Lee Country Park The River Lee Country Park is located in the Lee Valley Park and is managed by the Lee Valley Regional Park Authority. Covering on either side of the River Lee Navigation between Waltham Abbey and Broxbourne, it is an area of lakes, watercourse ...

at Holyfield Lake and out through Holyfield Weir. Flowing under Stubbins Hall Lane, it merges with the old

River Lea The River Lea ( ) is in South East England. It originates in Bedfordshire, in the Chiltern Hills, and flows southeast through Hertfordshire, along the Essex border and into Greater London, to meet the River Thames at Bow Creek. It is one of t ...

Fishers Green Fishers Green is a settlement to the north of the town of Waltham Abbey, Essex, England, in the parish of Waltham Abbey. It lies on the flood plain of the River Lea. Description In the years following World War II much of the flood plain was ...

. After skirting Seventy Acres Lake and then Hooks Marsh Lake, the channel is incorporated into the Horsemill Stream, also known as Waltons Walk. The water forms a natural boundary for the Royal Gunpowder Mills as it passes through the mechanically controlled radial gates of the David Stoker

near Waltham Abbey. Now flowing parallel with the Lee Navigation, and only yards apart, the channel flows firstly under the A121 road and through Rammey Marsh Sluice - a set of three computer-controlled vertical lift sluice gates and then under the

M25 motorway The M25 or London Orbital Motorway is a major road encircling most of Greater London. The motorway is one of the most important roads in the UK and one of the busiest. Margaret Thatcher opened the final section in 1986, making the M25 the lon ...

to be joined by

Cobbins Brook Cobbins Brook is a minor tributary of the River Lea. It forms to the north of Epping, Essex and flows past Epping Upland, Waltham Abbey until it joins the River Lee Flood Relief Channel below the M25 near Rammey Marsh. Queen Boudica A local ...

before flowing through Newman's Sluice – a set of four computer-controlled vertical lift sluice gates.

Greater London

The channel crosses

Rammey Marsh Rammey Marsh is located in the Lee Valley Park at Enfield Lock, Enfield, and covers approximately . The site is owned and managed by the Lee Valley Regional Park Authority.Royal Small Arms Factory The Royal Small Arms Factory (RSAF) was a UK government-owned rifle factory in Enfield (though some parts were in Waltham Abbey), adjoining the Lee Navigation in the Lea Valley. The factory produced British military rifles, muskets and swords f ...

, which is now a housing development called Enfield Island Village. Further downstream, the channel merges with the

to become the man-made, concrete-banked River Lee Diversion as it skirts the eastern perimeter of the King George V Reservoir, the first of the Lee Valley Reservoir Chain, and then the William Girling Reservoir. The river forms the boundary of the London Borough of Enfield and

Waltham Forest The London Borough of Waltham Forest () is a London borough in north-east London, England. Its population is estimated to be 276,983 in 2019. It borders five other London boroughs: Enfield to the north-west, Haringey to the west, Hackney to t ...

and the historical boundary between

Middlesex Middlesex (; abbreviation: Middx) is a Historic counties of England, historic county in South East England, southeast England. Its area is almost entirely within the wider urbanised area of London and mostly within the Ceremonial counties of ...

and

Essex Essex () is a county in the East of England. One of the home counties, it borders Suffolk and Cambridgeshire to the north, the North Sea to the east, Hertfordshire to the west, Kent across the estuary of the River Thames to the south, and G ...

. Flowing under the North Circular Road and close to Banbury Reservoir, it splits from the River Lee Diversion to cross

Tottenham Marshes The Tottenham Marshes are located at Tottenham in the London Borough of Haringey. The marshes cover over and became part of the Lee Valley Park in 1972. The marsh is made up of three main areas: Clendish Marsh, Wild Marsh West and Wild Marsh Ea ...

, and passes close to the

Lockwood Reservoir Lockwood Reservoir is located in Walthamstow in the London Borough of Waltham Forest. It is one of the ten Walthamstow Reservoirs, which are part of the Lee Valley Reservoir Chain. The reservoirs supply drinking water to London and are owned ...

High Maynard Reservoir High Maynard Reservoir is located in Walthamstow in the London Borough of Waltham Forest. The storage reservoir is one of the Lee Valley Reservoir Chain and supplies drinking water to London. History The reservoir was built in the mid-19th cen ...

and

Low Maynard Reservoir Low Maynard Reservoir is located in Walthamstow in the London Borough of Waltham Forest. The storage reservoir is part of the Lee Valley Reservoir Chain and supplies drinking water to London. History The reservoir was constructed in the mid 19t ...

. Flowing firstly under Forest Road (

A503 road List of A roads in zone 5 in Great Britain starting north/east of the A5, west of the A6, south of the Solway Firth/Eden Estuary The River Eden is a river in Fife in Scotland, and is one of Fife's two principal rivers, along with the Lev ...

) and then the Gospel Oak to Barking line, it skirts the

Walthamstow Reservoirs Walthamstow Wetlands is a nature reserve in Walthamstow, east London, adjacent to the historic Essex-Middlesex border on the River Lea. It is focused on the Walthamstow Reservoirs, built by the East London Waterworks Company between 1853 and 1 ...

close to

Walthamstow Marshes Walthamstow Marshes, is a biological Site of Special Scientific Interest in Walthamstow in the London Borough of Waltham Forest. It was once an area of lammas land – common land used for growing crops and grazing cattle. In aviation histo ...

. It passes under Coppermill Lane before flowing under the

Lea Valley Line The Lea Valley lines are two Commuter rail in the United Kingdom, commuter lines and two branches in north-east London, so named because they run along the Lower Lea Valley of the River Lea. They were part of the Great Eastern Railway, now par ...

as the channel approaches Lea Bridge Road, part of the

A104 road This is a list of roads designated A104. Roads entries are sorted in the countries alphabetical order. * A104 road (England), the road from Islington Green to Epping in London, England * A104 road (Kenya), the road from Nairobi, Kenya to the Ta ...

. It crosses

Hackney Marshes Hackney Marshes is an area of open space in London's Lower Lea Valley, lying on the western bank of the River Lea. It takes its name from its position on the eastern boundary of Hackney, the principal part of the London Borough of Hackney, and ...

and passes through a culvert before joining the

Old River Lea The Old River Lea is the former natural channel of the River Lea below Lea Bridge, in the London Borough of Hackney. The Old River forms a large meander from the Middlesex Filter Beds Weir to rejoin the main channel of the River Lee Navigati ...

close to the New Spitalfields Market. Passing under the

Eastway East Cross Route (ECR) is a dual-carriageway road constructed in east London as part of the uncompleted Ringway 1 as part of the London Ringways plan drawn up the 1960s to create a series of high speed roads circling and radiating out from cen ...

road and then flowing under the A115 (Carpenter's Road) to meet the

Waterworks River Waterworks River is a river, at one time a tidal river, in the London Borough of Newham, one of the Bow Back Rivers that flow into the Bow Creek part of the River Lea, which in turn flows into the River Thames. The river is an artificial chann ...

below

Carpenter's Road Lock Carpenter's Road Lock is a rising radial lock in the London Borough of Newham, near Marshgate Lane in Stratford, England. It is located on the Bow Back Rivers and was constructed in 1933/34. It is the only lock in Britain with rising radial g ...

in Stratford, the channel continues through the

Prescott Channel The Prescott Channel was built in 1930–35 as part of a flood relief scheme for the River Lee Navigation in the East End of London, England, and was named after Sir William Prescott, the then chairman of the Lee Conservancy Board.

and Bow Creek to reach the Thames at Leamouth.

References

External links

Glen Faba lakes

Nazeing Meads lakes

Seventy Acres lake-Conservation Project

Waltons Walk fishery
{{DEFAULTSORT:Lee Flood Relief Channel Rivers of Essex Rivers of Hertfordshire Rivers of London Water supply and sanitation in London Thames Water

Flood Relief Channel Flood control channels are large and empty basins which let water flow in and out (except during flooding) or dry channels that run below the street levels of some larger cities, so that if and when a flood occurs, the water will run into these ch ...