The Middlesex Filter Beds Weir, or Lea Bridge Road Weir, marks the start of the Hackney Cut

Hackney Cut

The Hackney Cut is an artificial channel of the River Lee Navigation built in 1770 by the River Lea Trustees to straighten and improve the Navigation. It begins at by the Middlesex Filter Beds Weir, below Lea Bridge...

, an artificial channel of the River Lee Navigation

River Lee Navigation

The Lee Navigation is a canalised river incorporating the River Lea . Its course runs from Hertford Castle Weir all the way to the River Thames at Bow Creek. The first lock of the navigation is Hertford Lock the last being Bow Locks....

 built in 1770, in the London Borough of Hackney

London Borough of Hackney

The London Borough of Hackney is a London borough of North/North East London, and forms part of inner London. The local authority is Hackney London Borough Council....

. The weir lies between the former Middlesex Filter Beds – now a nature reserve – and the Thames Water treatment works at Lea Bridge

Lea Bridge

Lea Bridge is a district of the London Borough of Hackney. It is situated to the northeast of the borough and bounded by Upper Clapton to the north, Lower Clapton to the south, and the River Lee Navigation to the east...

 Road.

Excess water from the Navigation passes over the weir into the former natural channel of the River Lee

River Lee (England)

The River Lea in England originates in Marsh Farm , Leagrave, Luton in the Chiltern Hills and flows generally southeast, east, and then south to London where it meets the River Thames , the last section being known as Bow Creek.-Etymology:...

 that passes in a large loop to the east of the modern water course, as the Old River Lea

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 Navigation below Old Ford Lock, just west of the 2012 Olympic...

. The natural water course travels 2 miles (3.2 km) and rejoins the Navigation below Old Ford Lock

Old Ford Lock

Old Ford Lock is a paired lock and weir on the River Lee Navigation, in the London Borough of Tower Hamlets, England. It is at Bow on the east side of London...

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