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 the time of year, the river tide rises and falls twice a day by up to 7 m (24 ft). Because the tide goes against the outflow of fresh water from the Thames Basin,
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 due to a slow but continuous rise in high water level, caused by the extremely slow 'tilting' of Britain (up in the north and down in the south) due to post-glacial rebound and the gradual rise in sea levels due to climate change. 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.
Responsibilities
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.
Navigation
The River is navigable to large ocean-going ships as far as the Pool of London at London Bridge. The Port of London is the United Kingdom's second largest port by tonnage. Today, little commercial traffic passes above the Thames Barrier. Central London is visited occasionally by cruise ships or warships, which moor alongside HMS Belfast, and a few smaller aggregate or refuse vessels, operating from wharves in the west of London. Most trade is handled by the Port of Tilbury, roll-on/roll-off ferry terminals at Dagenham and Dartford, and petroleum products handling facilities at Purfleet, Coryton and Canvey Island.
There is a speed limit of west of Wandsworth Bridge and in tributary creeks, and except for authorised vehicles, between Wandsworth Bridge and Margaretness.
The tidal river is used for leisure navigation. In London sections there are many sightseeing tours in tourist boats past 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 Greenwich to Ham. 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 via Bow Lock.
Environment
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).