Tideway

[tahyd-wey]

The Tideway is a name given to the part of the River Thames in England that is subject to tides. This stretch of water is downstream from the Teddington Lock and is just under 160 km long. The Tideway includes the Thames Estuary, Thames Gateway and the Pool of London.

Tidal activity

Depending on the time of year, the river tide rises and falls twice a day by anything up to 7 m (24 ft) and takes longer to flow out (between 6 to 9 hours) than it does to flow in (4 to 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 than London Bridge, and Teddington about an hour later. London is vulnerable to flooding by storm surges. The threat has increased over time due to a slow but continuous rise in high water level, caused by both the slow 'tilting' of Britain (up in the north and down in the south) caused by post-glacial rebound and the gradual rise in sea levels due to climate change. The Thames Barrier was constructed across the Thames at Woolwich to deal with this threat.

Responsibilities

This part of the river is managed by the Port of London Authority and is often referred to as the Port of London. The upstream limit of the PLA's authority is marked by an obelisk just short of Teddington Lock. The PLA is responsible for just one lock on the Thames - Richmond Lock.

Within London the Thames is policed by the Thames Division, the River Police arm of London’s Metropolitan Police. Essex Police and Kent Police have responsibilities on the parts of the river downstream outside the metropolitan area. Notable criminal investigations have included the Roberto Calvi and Torso in the Thames cases. The London Fire Brigade has a fire boat on the river.

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. As a result, there are four lifeboat stations on the river Thames based at Teddington, Chiswick Pier, Tower Pier and Gravesend.

Navigation

The river is navigable to large ocean-going ships as far as the Pool of London and London Bridge and is the United Kingdom's second largest port by tonnage. Today little commercial traffic passes above the Thames Barrier, and central London sees only the occasional visiting cruise ship or warship, moored alongside HMS Belfast and a few smaller aggregate or refuse vessels, operating from wharves in the west of London. Most trade is handled by Tilbury docks, ro-ro ferry terminals at Dagenham and Dartford, and petroleum products handling facilities at Purfleet, Coryton and Canvey Island.

The tidal part of the river has a speed limit of west (upstream) of the Wandsworth Bridge; east of this point, there is no speed limit although boats are not allowed to create undue wash. An episode of Top Gear in 2007 showed Jeremy Clarkson driving a boat at claimed speeds of up to near Canary Wharf.

The tidal river is used for leisure navigation. In London sections there are many sightseeing tours in tourist boats, past the more famous riverside attractions such as the Houses of Parliament and the Tower of London as well as regular riverboat services provided by London River Services. This section is not suitable for sporting activity because of the strong stream through the bridges. Rowing has a significant presence upstream of Putney Bridge, while sailing takes place in the same area and also along the coasts of the Estuary. The annual Great River Race for traditional rowed craft takes place over the stretch from Ham to Greenwich. Thames meander challenges along the length of the Thames from Lechlade often pass through the London sections and finish well downstream, for example at Gravesend Pier.

The Grand Union Canal joins the river at Brentford, with a branch - the Regent's Canal - joining at Limehouse Basin. The other part of the canal network still connecting on the Tideway is the River Lea Navigation.

Environment

Some low-lying areas beside the tidal section of the Thames regularly flood at spring tides. However, in recent years, the flooding has been occurring more frequently at unusual times. One such example exists at Chiswick Lane South in London's W4 postal district, where the river now bursts its banks almost daily between March and September.

Although efforts to clean up the Tideway have led to the reintroduction of marine life and birds, the environment of the Tideway is still poor. High levels of rainfall in London cause hundreds of thousands of tonnes of raw sewage to be poured into the Tideway several times per year, causing the deaths of marine life and health hazards for river users.

Sections of the Tideway

Thames Estuary

The Thames Estuary applies to 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. It has the world's second largest tidal movement, where the water can rise by 4 metres moving at a speed of 8 miles per hour. The whole estuary extends up the river into London near Tower Bridge, but this is divided into the Outer Estuary up to the Isle of Sheppey, and the Inner Estuary, designated the Thames Gateway above the Isle of Sheppey. The shore of the Outer estuary consists of saltmarshes and mudflats, but there are man-made embankments along much of the route where the land behind is now cultivated or used for grazing. Parts of the Outer estuary constitute a major shipping route.

Thames Gateway

The Gateway is some 40 miles (60 KM) long, stretching from the Isle of Sheppey to Westferry 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.

Tributaries

River Ingrebourne
River Rom (lower reaches known as the Beam)
River Roding (tidal reach known as 'Barking Creek')
River Lea or Lee (tidal reach known as 'Bow Creek')
Ravensbourne (tidal reach known as 'Deptford Creek')

Islands

Isle of Grain— actually a peninsula
Two Tree Island
Canvey Island
Lower Horse Island
Frog Island, Rainham
Isle of Dogs — actually a peninsula

Major Crossings

Dartford Crossing including two Dartford Tunnels (1963 and 1980) and the cable-stayed Queen Elizabeth II Bridge (1991)
Blackwall Tunnels (Alexander Binnie, 1897; second bore 1967)
Jubilee Line and Docklands Light Railway tunnels
Greenwich foot tunnel (Alexander Binnie, 1902)

Pool 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, ofen using converted warehouses. In the Upper Pool this provided scope for office development in the City of London and Southwark.

Major Crossings

Rotherhithe Tunnel (Maurice Fitzmaurice, 1908)
Thames Tunnel (Wapping to Rotherhithe Tunnel) (Marc Brunel, 1843; the world's first underwater tunnel, now part of the East London Line)
Tower Bridge (1894)

Inner London

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

North Bank	South Bank
Monument St Paul's Cathedral Inner Temple Somerset House Victoria Embankment HMS President HMS Wellington Cleopatra's Needle Charing Cross railway station Norman Shaw Building Houses of Parliament Tate Britain Thames Embankment	Southwark Cathedral St Saviour's Dock Globe Theatre Tate Modern Royal National Theatre Royal Festival Hall London Eye Albert Embankment County Hall, London St Thomas' Hospital Lambeth Palace SIS Building Battersea Power Station

Riverboats carry tourists up down and across the river, and also provide regular commuter service.

Major Crossings

Northern Line, Waterloo & City Line, Bakerloo Line, Jubilee Line, Victoria Line, tunnels
London Bridge (1973)
Cannon Street Railway Bridge (1982)
Southwark Bridge (1921)
Millennium Bridge (2002)
Blackfriars Railway Bridge (1886)
Blackfriars Bridge (1869)
Waterloo Bridge (1945) (the "women's bridge")
Hungerford Footbridges (Golden Jubilee Bridges) (2002)
Charing Cross (Hungerford) Bridge (1864)
Westminster Bridge (1862)
Lambeth Bridge (1932)
Vauxhall Bridge (1906)
Grosvenor Bridge (Victoria Railway Bridge) (1859)
Chelsea Bridge (1937)
Albert Bridge (1873)
Battersea Bridge (Sir Joseph Bazalgette, 1890) (Henry Holland, 1771)
Battersea Railway Bridge (1863)
Wandsworth Bridge (1938)
Fulham Railway Bridge (1889)

Tributaries

Walbrook
River Fleet
Neckinger
Tyburn
Westbourne,
Counter's Creek (also known as 'Chelsea Creek')
Effra
Wandle

Outer London

From Putney Bridge to Teddington Lock, the river passes through inner and outer suburbs like 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, stretchs from Putney to Mortlake.

Tributaries

Islands