The Thames drains the whole of Greater London.[1]. At London, the water is slightly brackish with sea salt, being a mix of sea and fresh water. There are over 200 clubs on the river, and over 8,000 members of British Rowing (over 40% of its membership). The surface had sandy deposits from an ancient sea, laid over sedimentary clay (this is the blue London Clay). A significant number of ferries were provided specifically for navigation purposes. The principal tributaries of the River Thames on the Tideway include the rivers Brent, Wandle, Effra, Westbourne, Fleet, Ravensbourne (the final part of which is called Deptford Creek), Lea, Roding, Darent and Ingrebourne. The following centuries saw the conflict between king and barons coming to a head in AD 1215 when King John was forced to sign the Magna Carta on an island in the Thames at Runnymede. [19][20], The non-tidal section of the river is managed by the Environment Agency, which is responsible for managing the flow of water to help prevent and mitigate flooding, and providing for navigation: the volume and speed of water downstream is managed by adjusting the sluices at each of the weirs and, at peak high water, levels are generally dissipated over preferred flood plains adjacent to the river. Kingston's growth is believed to stem from its having the only crossing between London Bridge and Staines until the beginning of the 18th century. Before bridges were built, the main means of crossing the river was by ferry. Boat Builders & Boatyards on the River Thames, Best Spa Breaks at Stunning River Thames Hotels, Food & Drink Experiences along the Thames, Active Experiences On & Around the River Thames, Explore Thames Valley with Great Western Railway, Thames Path National Trail celebrates 20 Years, What’s on this Christmas along the River Thames, River Thames Conditions, Closures and Restrictions, Coronavirus Information for Visit Thames Partners, Latest information on Coronavirus (COVID-19). The marks of human activity, in some cases dating back to Pre-Roman Britain, are visible at various points along the river. See River Thames whale.[40]. It was the last major flood to affect central London, and, particularly following the disastrous North Sea flood of 1953, helped lead to the implementation of new flood-control measures that culminated in the construction of the Thames Barrier in the 1970s. By clicking on any major stream or river, the user can trace it upstream to its source(s) or downstream to where it joins a larger river or empties into the ocean. In 1715, Thomas Doggett was so grateful to a local waterman for his efforts in ferrying him home, pulling against the tide, that he set up a rowing race for professional watermen known as "Doggett's Coat and Badge". Salters operate services between Folly Bridge, Oxford and Staines. Safe headwaters and reaches are a summer venue for organised swimming, which is prohibited on safety grounds in a stretch centred on Central London. Click here to view the route map on screen; Charles Dickens' Our Mutual Friend (written in the years 1864–65) describes the river in a grimmer light. A screw turbine hydro-electric plant at Romney Lock to power Windsor Castle using two Archimedes' screws was opened in 2013 by the Queen. These activities have disappeared. Length of river - 356 km. Its catchment area covers a large part of south-eastern and a small part of western England; the river is fed by at least 50 named tributaries. Upstream of Wandsworth Bridge a speed limit of 8 knots (15 km/h) is in force for powered craft to protect the riverbank environment and to provide safe conditions for rowers and other river users. In more recent times Platts Eyot at Hampton was the place where Motor Torpedo Boats (MTB)s were built, Tagg's Island near Molesey was associated with the impresario Fred Karno and Eel Pie Island at Twickenham was the birthplace of the South East's R&B music scene. [73] Mercury concentrations in the River Thames decrease downstream from London to the outer Estuary with the total Hg levels ranging from 0.01 to 12.07 mg/kg, giving a mean of 2.10 mg/kg which is higher than many other UK and European river estuaries.[74][73].