The
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
River Thames
The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...
is navigable from
Cricklade
Cricklade is a town and civil parish on the River Thames in north Wiltshire, England, midway between Swindon and Cirencester. It is the first downstream town on the Thames. The parish population at the 2011 census was 4,227.
History
Cricklade ...
(for very small, shallow boats) or
Lechlade
Lechlade () is a town at the southern edge of the Cotswolds in Gloucestershire, England, south of Birmingham and west of London. It is the highest point at which the River Thames is navigable, although there is a right of navigation that contin ...
(for larger boats) to the sea, and this part of the river falls 71 meters (234 feet). There are 45
locks
Lock(s) may refer to:
Common meanings
*Lock and key, a mechanical device used to secure items of importance
*Lock (water navigation), a device for boats to transit between different levels of water, as in a canal
Arts and entertainment
* ''Lock ...
on the river, each with one or more adjacent
weir
A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...
s. These lock and weir combinations are used for controlling the flow of water down the river, most notably when there is a risk of flooding, and provide for navigation above the
tideway
The Tideway is a part of the River Thames in England which is subject to tides. This stretch of water is downstream from Teddington Lock. The Tideway comprises the upper Thames Estuary including the Pool of London.
Tidal activity
Depending on ...
.
History
From ancient times there were many obstructions across the Thames, for fish-pounds and millers' weirs. They are referred to by
Asserius Menevensis
Asser (; ; died 909) was a Welsh monk from St David's, Dyfed, who became Bishop of Sherborne in the 890s. About 885 he was asked by Alfred the Great to leave St David's and join the circle of learned men whom Alfred was recruiting for his c ...
in the ninth century and
Magna Carta (1215) states that "weirs, for the time to come, shall be demolished in the Thames and Medway, except on the sea coast." It appears this never happened. In the Middle Ages, the fall on the river in its middle and upper sections was used to drive
watermill
A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of ...
s for the production of flour and paper and various other purposes such as metal-beating. This involved the construction of weirs in order to divert water into the mills. The weirs, however, presented an obstacle to navigation and to solve this problem locks were built alongside the weirs to enable boats to be moved between levels.
Originally these were
flash locks that were essentially removable sections of weir. A boat moving downstream would wait above the lock until the lock was opened, which would allow a "flash" of water to pass through, carrying the boat with it. In the opposite direction boats would be winched or towed through the open lock. The difficulty of using flash locks, and the consequent loss of water and income to the miller, eventually led to their replacement with
pound locks. Locks similar to these early pound locks still exist on the river, although in many cases they have been enlarged and mechanised.
On the lower section, the river was
tidal
Tidal is the adjectival form of tide.
Tidal may also refer to:
* ''Tidal'' (album), a 1996 album by Fiona Apple
* Tidal (king), a king involved in the Battle of the Vale of Siddim
* TidalCycles, a live coding environment for music
* Tidal (servic ...
as far as
Staines until the beginning of the 19th century and was under the control of the
City of London
The City of London is a city, ceremonial county and local government district that contains the historic centre and constitutes, alongside Canary Wharf, the primary central business district (CBD) of London. It constituted most of London f ...
. The City's jurisdiction was marked by the
London Stone
London Stone is a historic landmark housed at 111 Cannon Street in the City of London. It is an irregular block of oolitic limestone measuring 53 × 43 × 30 cm (21 × 17 × 12"), the remnant of a once much larger object that had stood ...
. The principle of lock/weir combination, which maintained the depth of water for navigation and reduced the danger of flooding, was extended over the tidal section as far as
Teddington
Teddington is a suburb in south-west London in the London Borough of Richmond upon Thames. In 2021, Teddington was named as the best place to live in London by ''The Sunday Times''. Historically in Middlesex, Teddington is situated on a long me ...
in a series of locks built after 1810.
[
The first authority charged with managing navigation and lock building was the ]Oxford-Burcot Commission
The Oxford-Burcot Commission was the first Commission concerned with the management of the River Thames, appointed by an Act of Parliament of 1605 by James I to make the stretch of river from Burcot to Oxford navigable. The Commission took respons ...
, which built the locks at Iffley and Sandford below Oxford in 1633 and at Swift Ditch near Abingdon. In 1751, the Thames Navigation Commissioners
The Thames Navigation Commission managed the River Thames in southern England from 1751 to 1866. In particular, they were responsible for installing or renovating many of the locks on the river in the 18th and early 19th centuries
History
The f ...
were established and built eight locks between Shiplake Lock and Boulters lock between 1770 and 1773. The opening of the Thames and Severn Canal
The Thames and Severn Canal is a canal in Gloucestershire in the south-west of England, which was completed in 1789. It was conceived as part of a cargo route from Bristol and the Midlands to London, linking England's two largest rivers for bett ...
from Lechlade in 1789 led to the building of many of the locks upstream of Shiplake. The six locks built by the City of London Corporation
The City of London Corporation, officially and legally the Mayor and Commonalty and Citizens of the City of London, is the municipal governing body of the City of London, the historic centre of London and the location of much of the United King ...
on the tidal section below Staines between 1811 and 1815 required individual Acts of Parliament, and the Thames Conservancy
The Thames Conservancy (formally the Conservators of the River Thames) was a body responsible for the management of the that river in England. It was founded in 1857 to replace the jurisdiction of the City of London up to Staines. Nine years la ...
took over their management from the City in 1857. In 1866 the Thames Conservancy became responsible for all river management and installed more locks over the years, the last being Eynsham and King’s in 1928. In 1908 an Act transferred responsibility for the Thames from a point below Teddington Lock to the Port of London Authority, and this included Richmond Lock.[Fred S. Thacker ''The Thames Highway: Volume 1 General History'' David & Charles 1968] The Thames Conservancy was subsumed into the Thames Water Authority
The Thames Water Authority was one of ten regional water authorities created in the UK on 1 April 1974 under the provisions of the Water Act 1973 to bring together all the water management functions of the region in one public body.
Predece ...
in 1974. With the privatization of water supply in 1990 the river management functions passed to the new National Rivers Authority
The National Rivers Authority (NRA) was one of the forerunners of the Environment Agency of England and Wales, existing between 1989 and 1996.
Before 1989 the regulation of the aquatic environment had largely been carried out by the ten region ...
and in 1996 to the Environment Agency. Only Richmond Lock remains under the jurisdiction of the Port of London Authority.
Operation
Management
From the head of navigation at Cricklade to the start of the tidal
Tidal is the adjectival form of tide.
Tidal may also refer to:
* ''Tidal'' (album), a 1996 album by Fiona Apple
* Tidal (king), a king involved in the Battle of the Vale of Siddim
* TidalCycles, a live coding environment for music
* Tidal (servic ...
section at Teddington Lock
Teddington Lock is a complex of three locks and a weir on the River Thames between Ham and Teddington in the London Borough of Richmond upon Thames, England. Historically in Middlesex, it was first built in 1810.
The limit of legal po ...
, the river is managed by the Environment Agency, which has the twin responsibilities of managing the flow of water to control flooding and provide navigable water depths and also regulating and promoting navigation on the river. As a result, all the locks and weirs on the river, except the semi-tidal Richmond Lock, are owned and operated by the Environment Agency. Richmond Lock is managed by the Port of London Authority.
Most of the Environment Agency's locks and weirs are staffed by a lock keeper
A lock keeper, lock tender, or lock operator looks after a canal or river lock, operating it and if necessary maintaining it or organizing its maintenance. Traditionally, lock keepers lived on-site, often in small purpose-built cottages. A lock ke ...
, who often lives in a house adjacent to the lock. The lock keeper's duties involve both operating the lock, and managing the river levels above the lock by adjusting the weir openings.
Locks
Most locks are operated by their keepers between 9 a.m. and 7 p.m. from June to August, with progressively shorter hours as the hours of daylight reduce, and they are not operated during the lock-keeper's lunch hour between 1 p.m. and 2 p.m. During the summer months Assistant Lock Keepers and volunteers are employed to deal with the heavy traffic and avoid the lunch-time closure. However Teddington Lock
Teddington Lock is a complex of three locks and a weir on the River Thames between Ham and Teddington in the London Borough of Richmond upon Thames, England. Historically in Middlesex, it was first built in 1810.
The limit of legal po ...
, which is the most downstream of the Environment Agency locks and separates the long Kingston reach of the non-tidal river from Hampton Court
Hampton Court Palace is a Grade I listed royal palace in the London Borough of Richmond upon Thames, southwest and upstream of central London on the River Thames. The building of the palace began in 1514 for Cardinal Thomas Wolsey, the chie ...
to the tideway, is staffed 24 hours a day. During winter, some locks will be closed for maintenance and the status has to be checked with the Environment Agency.
The locks at the upper end of the river, from St John's Lock to King's Lock
King's Lock is a lock on the River Thames in England. It is in open country to the north of Oxford, Oxfordshire, on the southern bank of the river. The lock was one of the last pound locks built on the Thames, built by the Thames Conservancy i ...
, are manually operated. All other locks on the Thames are hydraulically operated. All locks, except Teddington, can be operated by boat crews outside manning hours, using the adapted system of "public power", which allows boaters to use the hydraulic machinery at reduced power, except during the hours of darkness.
Locks are popular visitor attractions, and many serve refreshments. Locks were often built adjacent to islands and therefore many are situated in remote locations, hard to find and can only be reached on foot. Many locks also have moorings that can be used overnight, and some include electric charging points for electric powered boats.
All the locks have obvious access from the Thames Path
The Thames Path is a National Trail following the River Thames from its source near Kemble in Gloucestershire to the Woolwich foot tunnel, south east London. It is about long. A path was first proposed in 1948 but it only opened in 1996.
The ...
, except for Whitchurch Lock
Whitchurch Lock is a lock and weir on the River Thames in England. It is a pound lock, built by the Thames Navigation Commissioners in 1787. It is on an island near the Oxfordshire village of Whitchurch-on-Thames and is accessible only by b ...
which is within an island and only accessible by boat; Cookham Lock
Cookham Lock is a lock with weirs situated on the River Thames near Cookham, Berkshire, about a half-mile downstream of Cookham Bridge. The lock is set in a lock cut which is one of four streams here and it is surrounded by woods. On one si ...
requires a 1km diversion from the Thames Path; and Marlow Lock requires a short diversion.
Weirs
The Environment Agency has the responsibility of managing the flow of water along the length of the river to prevent flooding on particular reaches and to maintain navigation depths. The volume and speed of water down the river is managed by adjusting the gates at each weir. Occasionally this can result in a fast stream rendering navigation more hazardous. These conditions are indicated by yellow or red warning boards on the lock gates and the status of all locks is published by the Agency. The Agency cannot legally stop navigation when the red boards are out, but continuing to travel is inadvisable and may invalidate a boater's insurance.
Occasionally flooding is unavoidable, and the Agency issues Flood Warnings with three levels of severity - Flood Alert, Flood Warning, and Severe Flood Warning.
In recent years the Salmon Conservancy has been installing fish ladder
A fish ladder, also known as a fishway, fish pass, fish steps, or fish cannon is a structure on or around artificial and natural barriers (such as dams, locks and waterfalls) to facilitate diadromous fishes' natural migration as well as move ...
s at weirs to allow salmon
Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...
to travel up river.
Today some weirs are often used recreationally by kayakers
A kayak is a small, narrow watercraft which is typically propelled by means of a double-bladed paddle. The word kayak originates from the Greenlandic word '' qajaq'' ().
The traditional kayak has a covered deck and one or more cockpits, each s ...
and canoeists
A canoe is a lightweight narrow watercraft, water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using a single-bladed paddle.
In British Englis ...
for activities such as whitewater slalom
Canoe slalom (previously known as whitewater slalom) is a competitive sport with the aim to navigate a decked canoe or kayak through a course of hanging downstream or upstream gates on river rapids in the fastest time possible. It is one of th ...
and playboating
Canoe freestyle (also known as playboating) is a discipline of whitewater kayaking or canoeing where people perform various technical moves in one place (a playspot), as opposed to downriver whitewater canoeing or kayaking where the objective is ...
. Specifically, Hambleden Weir and Boulter's Weir have EA sanctioned modifications made to them for such use.
Reaches
The locks and weirs, in effect, break the river up into 44 lakes or lock reaches. Each lock controls the reach above it and thus identifies it. Each reach has its own character and points of interest.
Many reaches host regattas and other events and these are coordinated through a River User’s Group for the reach. The Environment Agency may close all or part of a reach for an event, but most regattas only require one side of the river which may then be closed off.
When the boats were horse drawn, a towpath
A towpath is a road or trail on the bank of a river, canal, or other inland waterway. The purpose of a towpath is to allow a land vehicle, beasts of burden, or a team of human pullers to tow a boat, often a barge. This mode of transport w ...
was needed on the bank side. This towpath has formed the basis for the Thames Path
The Thames Path is a National Trail following the River Thames from its source near Kemble in Gloucestershire to the Woolwich foot tunnel, south east London. It is about long. A path was first proposed in 1948 but it only opened in 1996.
The ...
which runs between the source and mouth of the river. The path runs between locks and is therefore often the main means of access on land. Where the towpath changes from one side of the river to the other ferries were once provided. These have now almost all disappeared and the Thames Path has to be diverted to the nearest bridge, often a considerable distance, to cope with this.
Foot crossings
All of the Thames locks have walkways on top of the lock gates, so except at Whitchurch Lock one can cross to the lock island from the adjacent bank.
Upstream of Wallingford, many locks also have walkways on top of the weir to cross the whole river. Downstream of Wallingford,
Caversham Lock
Caversham Lock is a lock and main weir on the River Thames in England at Reading, Berkshire. Both the lock and main weir are connected to De Bohun Island (colloquially known as Lock Island). The Thames Navigation Commissioners built the ori ...
and Boulters Lock have footbridges nearby, and Hambleden Lock
Hambleden Lock is a lock with a long weir situated on the River Thames in England, about 2 miles downstream of Henley Bridge. The lock is on the Berkshire bank between Aston and Remenham. Built by the Thames Navigation Commission in 1773, ...
has a walkway on top of the weir, but the other locks below Wallingford do not allow river crossing on foot.
List of locks and weirs
The list of locks, weirs and ferries is given in upstream to downstream order, from source to sea. Most of the older flash locks have disappeared and there are only three ferries still operating (Weybridge, Hampton and Hammerton's). Nearly all of the older weirs and most of the current ones once had associated mills, fifteen of which are mentioned in the Domesday book
Domesday Book () – the Middle English spelling of "Doomsday Book" – is a manuscript record of the "Great Survey" of much of England and parts of Wales completed in 1086 by order of King William I, known as William the Conqueror. The manus ...
, but very few of these survive. A few weirs had bucks for catching eels.
Additionally, Blake's Lock
Blake's Lock is a lock situated on the River Kennet in Reading, Berkshire, England. It is on the short reach of the River Kennet which is administered as if it were part of the River Thames and is hence owned and managed by the Environment ...
is located on a reach of the River Kennet
The Kennet is a tributary of the River Thames in Southern England. Most of the river is straddled by the North Wessex Downs AONB (Area of Outstanding Natural Beauty). The lower reaches have been made navigable as the Kennet Navigation, which â ...
that is administered by the Environment Agency as part of the River Thames, and is often counted as a Thames Lock. It is the only manual Thames lock below Oxford.
The tide flows as far as Teddington Lock: the weir at Richmond Lock is only used at low tide, to maintain the water level above it.
Chalmore Lock (1838) was removed in 1883.
See also
* Thames Barrier
The Thames Barrier is a retractable barrier system built to protect the floodplain of most of Greater London from exceptionally high tides and storm surges moving up from the North Sea. It has been operational since 1982. When needed, it is c ...
* Crossings of the River Thames
The River Thames is the second-longest river in the United Kingdom, passes through the capital city, and has many crossings.
Counting every channel – such as by its islands linked to only one bank – it is crossed by over 300 brid ...
* Islands in the River Thames
This article lists the islands in the River Thames, or at the mouth of a tributary (marked †), in England. It excludes human-made islands built as part of the building of forty-five two-gate locks which each accompany a weir, and islets subordi ...
* Tributaries of the River Thames
This article lists the tributaries of the River Thames from the sea to the source, in England. There are also secondary lists of backwaters of the river itself and the waterways branching off.
Note: the River Medway shares the saline lower T ...
References
External links
A user's guide to the River Thames
(published by th
Environment Agency
More information about Thames locks, bridges and canals.
{{DEFAULTSORT:Locks And Weirs On The River Thames
River Thames
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