The River Lea originates in the Chiltern Hills, England, and flows southeast through east London where it meets the River Thames, the last looping section being known as Bow Creek. It is one of the largest rivers in London and the easternmost major tributary of the Thames. Its valley creates a long chain of marshy ground along its lower length, much of which has been used for gravel and mineral extraction, reservoirs and industry. Much of the river has been canalised to provide a navigable route for boats into eastern Hertfordshire, known as the Lee Navigation. While the lower Lea remains somewhat polluted, its upper stretch and tributaries, classified as chalk streams, are a major source of drinking water for London. A diversion known as the New River, opened in 1613, abstracts clean water away from the lower stretch of the river for drinking. Its origins in the Chilterns contribute to the extreme hardness of London tap water.
The Hertford Union Canal or Duckett's Cut is just over 1 mile (1.6 km) long in the London Borough of Tower Hamlets in East London. It connects the Regent's Canal to the Lee Navigation. It was opened in 1830 but quickly proved to be a commercial failure. It was acquired by the Regents Canal Company in 1857, and became part of the Grand Union Canal in 1927.
The Lee Navigation is a canalised river incorporating the River Lea. It flows from Hertford Castle Weir to the River Thames at Bow Creek; its first lock is Hertford Lock and its last Bow Locks.
Enfield Lock is an area in the London Borough of Enfield, north London. It is approximately located east of the Hertford Road between Turkey Street and the Holmesdale Tunnel overpass, and extends to the River Lee Navigation, including the Enfield Island Village. The locality gains its name from the lock on the River Lee Navigation. Today's Enfield Lock was rebuilt in 1922. The area forms part of the Lee Valley Park and the Enfield Lock Conservation Area. On its eastern boundary Enfield Lock has marshland formerly used as a testing site between the Royal Small Arms Factory and the Gunpowder Mills. To the south is Brimsdown, the north Waltham Cross and to the west Bullsmoor and Freezywater. Enfield Lock forms part of the London boundary.
This article contains a complete list of locks and weirs on the River Lea/River Lee Navigation.
Hertford Lock (No1) is a lock situated on the River Lea on the eastern side of Hartham Common, Hertford in the English county of Hertfordshire. It is owned and managed by British Waterways and is the first lock of the River Lee Navigation.
The Small River Lea is a minor tributary of the River Lea, which flows through the Lee Valley Park between Cheshunt and Enfield Lock. It forms part of the Turnford and Cheshunt Pits Site of Special Scientific Interest (SSSI) as it flows through the River Lee Country Park.
The River Lee Flood Relief Channel (FRC) is located in the Lea Valley and flows between Ware, Hertfordshire, and Stratford, east London. Work started on the channel in 1947 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.
Pickett's Lock is a lock on the River Lee Navigation in the London Borough of Enfield, England and is located near Edmonton, London. It gives its name to the surrounding area of Picketts Lock. In common with other locks as far as Ponder's End Lock it is large enough to take barges of up to 130 tons. However it has not been upgraded to power operation and so it must be manually operated. It has gate paddles but these do not have gate baffles to mitigate the rush of water into the lock.
Stonebridge Lock (No16) is a paired lock on the River Lee Navigation in the London Borough of Haringey, England and is located near Tottenham, London. Like other locks as far as Ponder's End Lock it is large enough to take barges of up to 130 tons. The primary lock has been upgraded to mechanical operation, but the secondary lock is operated manually.
Tottenham Lock (No17) is a paired lock on the River Lee Navigation in the London Borough of Haringey, England and is located near Tottenham, London. Like other locks as far as Ponders End it is large enough to take barges of up to 130 tons. The primary lock has been upgraded to mechanical operation, but the secondary west lock is operated manually.
Ponders End Lock is a paired lock on the River Lee Navigation in England and is located near Ponders End, London. It is the last lock upstream that is large enough to take barges of up to 130 tons.
Rammey Marsh Lock is a lock on the River Lee Navigation at Enfield, London, England. The area adjacent to the lock is known as Rammey Marsh and close to the River Lee Flood Relief Channel.
Waltham Common Lock is a lock on the River Lee Navigation at Waltham Cross in Hertfordshire, England. The lock is located in the River Lee Country Park which is part of the Lee Valley Park and stands close to the Showground site now known as the Broxbourne White Water Canoe Centre - venue of the 2012 Olympics canoeing event. At the tail of the lock is the Powdermill Cut dug in 1806 to connect the Waltham Abbey Royal Gunpowder Mills directly to the then-new Navigation.
Aqueduct Lock (No8) is a lock on the River Lee Navigation close to Turnford.
Dobbs Weir Lock is a lock on the River Lee Navigation near Hoddesdon.
Hardmead Lock (No3) is a lock on the River Lee Navigation at Great Amwell close to the town of Ware.
The Middlesex Filter Beds Weir, or Lea Bridge Road Weir, marks the start of the Hackney Cut, an artificial channel of the River Lee Navigation built in 1770, in the London Borough of Hackney. The weir lies between the former Middlesex Filter Beds – now a nature reserve – and the Thames Water treatment works at Lea Bridge Road.
The Hackney Cut is an artificial channel of the Lee Navigation built in England in 1769 by the River Lea Trustees to straighten and improve the Navigation. It begins at the Middlesex Filter Beds Weir, below Lea Bridge, and is situated in the (modern) London Borough of Hackney. When built it contained two pound locks and a half-lock, but was rebuilt to handle larger barges in the 1850s, and now only Old Ford Lock, which is actually a duplicated pair, remains.
