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Tideway

Part of the River Thames subject to tides

Wikipedia contributorsAdapted for Fathomly · View authors
8 min read
Source updated September 1, 2026
Image credit is listed at the end of this article.

The Tideway is the 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.

01Tidal activity

Depending on the time of year, the river tide rises and falls twice a day by up to 7 m (24 ft). Because the rising tide is supplemented by the outflow of water from the Thames, it takes longer to subside (6-9 hours) than it does to rise (4-5 hours).

London Bridge is used as the basis for published tide tables giving the times of high tide. High tide reaches Putney about 30 minutes later.

Low-lying banks of London are naturally vulnerable to flooding by storm surges. The threat has increased mostly due to the rise in sea levels caused by climate change, but some is also due to the extremely slow 'tilting' of Great Britain (up in the north and down in the south) due to post-glacial rebound. The city and state have erected defensive barriers, including the Thames Barrier, which was constructed across the Thames at Woolwich to deal with this threat.

A Fast Response Targa 31 boat of the Marine Support Unit of the Metropolitan Police
A Fast Response Targa 31 boat of the Marine Support Unit of the Metropolitan Police

02Responsibilities

The Tideway, often referred to as the Port of London, is managed by the Port of London Authority (PLA). The upstream limit of this authority is marked by an obelisk just short of Teddington Lock and to seaward by the London Stone at Yantlet Creek. The PLA is responsible for one lock on the Thames: Richmond Lock.

Within Greater London, the Tideway is secured by the Metropolitan Police Marine Policing Unit. East of Crayford Ness, Essex Police and Kent Police assume responsibility in their respective jurisdictions. 21st-century criminal investigations have included the Roberto Calvi and Torso in the Thames cases.

London Fire Brigade maintains a fire boat on the river in central London.

As a result of the Marchioness disaster in 1989, when 51 people died, the Government asked the Maritime and Coastguard Agency, the Port of London Authority, and the Royal National Lifeboat Institution (RNLI) to work together to set up a dedicated Search and Rescue service for the tidal River Thames. Since 2002, four lifeboat stations have been established on the Thames, at: Teddington, Chiswick, Tower Pier, and Gravesend.

RNLI E class lifeboat based at Chiswick Pier performing a rescue
RNLI E class lifeboat based at Chiswick Pier performing a rescue

04Environment

Narrow low-lying belts beside the tidal section of the Thames regularly flood at spring tides, supporting brackish plants. One such example is at Chiswick Lane South, where the river, as pictured, overflows this road a few times per year. (Picture taken in 2006).

Although water quality has improved over the last 40 years and efforts to clean up the Tideway have led to the reintroduction of marine life and birds, the environment of the Tideway is still poor. Heavier rainfall in London causes overflows from pipes on the river banks from the standard type of sewer in the capital, the combined sewer. Around 39,000,000 m3 (3.9×1010 L) or 39 million tonnes of untreated sewage mixed with rainwater are released into the Tideway each year from sewage treatment works and combined sewer overflows (CSOs), averaging 106,849 m3 (106,849,000 L) per day or 106,849 tonnes per day. These CSOs can cause the deaths of marine life and health hazards for river users.

The Thames Tideway Scheme, under construction, aims to divert most of the overflow from sewers into a tunnel under the river.

The Thames Lock on the Grand Union Canal at Brentford in 2005
The Thames Lock on the Grand Union Canal at Brentford in 2005

05Thames Estuary

The Thames Estuary is bordered by the coast and the low-lying lands upstream between the mouth of the River Stour on the Essex/Suffolk border and The Swale in north Kent. It is now usually designated the Greater Thames Estuary and is one of the largest inlets on the coast of Great Britain. The water can rise by 4 metres moving at a speed of 8 miles per hour.

The estuary extends into London near Tower Bridge, and can be divided into the Outer Estuary up to the Swale at the west end of the Isle of Sheppey, and the Inner Estuary, designated the Thames Gateway above this point. The shore of the Outer Estuary consists of saltmarshes and mudflats, but there are manmade embankments along much of the route. Behind these, the land is cultivated or used for grazing. Parts of the Outer Estuary are on a major shipping route.

06Thames Gateway

The Gateway is some 70 kilometres (43 mi) long, stretching from the Isle of Sheppey to Limehouse in Tower Hamlets. Its boundary was drawn to capture the riverside strip that formerly hosted many land extensive industries, serving London and the South East. The decline of these industries has left a legacy of large scale dereliction and contaminated land, but an opportunity for major redevelopment. The area includes the London Docklands, Millennium Dome, London Riverside and Thames Barrier.

Major crossings

Tributaries

Islands and peninsulas

The River Thames flooding at Chiswick Lane South in 2006
The River Thames flooding at Chiswick Lane South in 2006

07Pool of London

The Pool of London is divided into two parts, the Lower Pool and Upper Pool. The Lower Pool traditionally runs from the Cherry Garden Pier in Rotherhithe to Tower Bridge. The Upper Pool consists of the section between Tower Bridge and London Bridge. In the 18th and 19th centuries the river was lined with nearly continuous walls of wharves running for miles along both banks, and hundreds of ships moored in the river or alongside the quays. The lack of capacity in the Pool of London prompted landowners to build London's Docklands with enclosed docks with better security and facilities. The abrupt collapse of commercial traffic in the Thames due to the introduction of shipping containers and coastal deep-water ports in the 1960s emptied the Pool and led to all of the wharves being closed down. The Lower Pool area was extensively redeveloped in the 1980s and 1990s to create new residential and commercial neighbourhoods, often using converted warehouses. In the Upper Pool this provided scope for office development in the City of London and Southwark.

Major crossings

The Grain Tower (constructed in 1855) and causeway, Isle of Grain, seen at low tide, 2008
The Grain Tower (constructed in 1855) and causeway, Isle of Grain, seen at low tide, 2008

08Inner London

Between London Bridge and Putney Bridge, the river passes through Central London and some of the most famous landmarks.

On the north bank, the river passes (from east to west) Monument, St Paul's Cathedral, Inner Temple, Somerset House, Victoria Embankment, HMS President, HMS Wellington, Cleopatra's Needle, Charing Cross railway station, Norman Shaw Buildings, Houses of Parliament, Tate Britain, and Thames Embankment.

On the south bank, it passes Southwark Cathedral, St Saviour's Dock, Shakespeare's Globe, Tate Modern, Royal National Theatre, Royal Festival Hall, London Eye, Albert Embankment, County Hall, London, St Thomas' Hospital, Lambeth Palace, SIS Building and Battersea Power Station.

River boats carry tourists up down and across the river, and also provide a regular commuter service.

Major crossings

Tributaries

(culverted tributaries largely converted to sewers are marked ‡)

The Queen Elizabeth II Bridge; opened in October, 1991
The Queen Elizabeth II Bridge; opened in October, 1991

09Outer London

From Putney Bridge to Teddington Lock, the river passes through inner and outer suburbs such as Hammersmith, Chiswick, Barnes, Richmond on Thames and Ham. This part of the Tideway is home to most of London's rowing clubs, and is the venue for training and racing throughout the year. The Championship Course over which The Boat Race and many other events are run, stretches from Putney to Mortlake.

Major crossings

Tributaries

Islands

Watch videos about TidewayExplainers and documentaries on YouTube (opens in a new tab)

Sources and credits

This article is adapted from the Wikipedia article “Tideway”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

Images, from Wikimedia Commons:

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