Aquatic mammals are also known to inhabit the Thames. The population of grey and harbour seals numbers up to 700 in the Thames Estuary. These animals have been sighted as far upriver as Richmond. [46] Bottlenose dolphins and harbour porpoises are also sighted in the Thames. [47] Needham, P. (1985). "Neolithic And Bronze Age Settlement on the Buried Floodplains of Runnymede". Oxford Journal of Archaeology. 4 (2): 125–137. doi: 10.1111/j.1468-0092.1985.tb00237.x. a b c Vane, C.H.; Beriro, D.; Turner, G. (2015), "Rise and fall of Mercury (Hg) pollution in sediment cores of the Thames Estuary, London, UK." (PDF), Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 105 (4): 285–296, doi: 10.1017/s1755691015000158, archived (PDF) from the original on 12 August 2016 , retrieved 17 June 2016 This part of the river is managed by the Port of London Authority. The flood threat here comes from high tides and strong winds from the North Sea, and the Thames Barrier was built in the 1980s to protect London from this risk. The next Roman bridges upstream were at Staines on the Devil's Highway between Londinium and Calleva ( Silchester). Boats could be swept up to it on the rising tide, with no need for wind or muscle power.

A timeline showing activities planned between 2023 and 2100. These include maintaining and adapting the existing flood defence system, and raising defences. The timeline shows 4 options for the future of the Thames Barrier. We need to decide on one by 2040 and implement it by 2070. Securing land Another major consequence of John's reign was the completion of the multi-piered London Bridge, which acted as a barricade and barrage on the river, affecting the tidal flow upstream and increasing the likelihood of the river freezing over. In Tudor and Stuart times, various kings and queens built magnificent riverside palaces at Hampton Court, Kew, Richmond on Thames, Whitehall and Greenwich.The Thames Barrier protects the area by controlling tidal water levels. There are also secondary tidal defences along the Thames frontage, some of which are part of buildings. Fluvial flooding from the Thames is unlikely to be a problem for this policy unit because fluvial flood levels would not overtop the defences. Update on Environment Agency Investigation - Creating a better place". environmentagency.blog.gov.uk. 12 May 2022 . Retrieved 21 April 2023. The springs at Seven Springs flow throughout the year, while those at Thames Head are seasonal (a winterbourne). With a length of 215mi (346km), [20] the Thames is the longest river entirely in England. (The longest river in the United Kingdom, the Severn, flows partly in Wales.) However, as the River Churn, sourced at Seven Springs, is 14mi (23km) longer than the section of the Thames from its traditional source at Thames Head to the confluence, the overall length of the Thames measured from Seven Springs, at 229mi (369km), is greater than the Severn's length of 220mi (350km). [21] Thus, the "Churn/Thames" river may be regarded as the longest natural river in the United Kingdom. The stream from Seven Springs is joined at Coberley by a longer tributary which could further increase the length of the Thames, with its source in the grounds of the National Star College at Ullenwood. Science-fiction novels make liberal use of a futuristic Thames. The utopian News from Nowhere by William Morris is mainly the account of a journey through the Thames valley in a socialist future. The Thames features in H. G. Wells' The War of the Worlds. The Thames also features prominently in Philip Pullman's His Dark Materials trilogy, as a communications artery for the waterborne Gyptian people of Oxford and the Fens, and as a prominent setting for his novel La Belle Sauvage.

Bailey, David (15 May 2012). "Tracing the source of the Thames". BBC News. Archived from the original on 27 August 2020 . Retrieved 12 September 2018. There are several watersports prevalent on the Thames, with many clubs encouraging participation and organising racing and inter-club competitions.So extensive have the changes to this landscape been that what little evidence there is of man's presence before the ice came has inevitably shown signs of transportation here by water and reveals nothing specifically local. Likewise, later evidence of occupation, even since the arrival of the Romans, may lie next to the original banks of the Brent but have been buried under centuries of silt. [51] Roman Britain [ edit ] Mercury (Hg) is an environmentally persistent heavy metal which can be toxic to marine life and humans. Sixty sediment cores of 1 m in depth, spanning the entire tidal River Thames between Brentford and the Isle of Grain, have been analysed for total Hg. The sediment records show a clear rise and fall of Hg pollution through history. [90] Mercury concentrations in the River Thames decrease downstream from London to the outer Estuary, with the total Hg levels ranging from 0.01 to 12.07mg/kg, giving a mean of 2.10mg/kg which is higher than many other UK and European river estuaries. [91] [90]

The Victorian era was one of imaginative engineering. The coming of the railways added railway bridges to the earlier road bridges and also reduced commercial activity on the river. However, sporting and leisure use increased with the establishment of regattas such as Henley and the Boat Race. One of the worst river disasters in England was on 3 September 1878, when the crowded pleasure boat Princess Alice collided with the Bywell Castle, killing over 640 people. Thiess International Riverprize – International RiverFoundation". riverfoundation.org.au. Archived from the original on 1 August 2017 . Retrieved 1 August 2017. In 1974 the Thames Conservancy became part of the new Thames Water Authority. When Thames Water was privatised in 1990, its river management functions were transferred to the National Rivers Authority, in 1996 subsumed into the Environment Agency. The River Thames has played several roles in human history: as an economic resource, a maritime route, a boundary, a fresh water source, a source of food and more recently a leisure facility. In 1929, John Burns, one-time MP for Battersea, responded to an American's unfavourable comparison of the Thames with the Mississippi by coining the expression "The Thames is liquid history". In the late 1990s, the 7mi (11km) long Jubilee River was built as a wide "naturalistic" flood relief channel from Taplow to Eton to help reduce the flood risk in Maidenhead, Windsor and Eton, [62] although it appears to have increased flooding in the villages immediately downstream.Grahame, Kenneth (2009). The Wind in the Willows: An Annotated Edition. Harvard University Press. ISBN 978-0674034471. London's super sewer won't solve the city's epic poop problem". Wired UK. ISSN 1357-0978 . Retrieved 21 April 2023. The form of speech of many of the people of the area, principally the accents of those from Kent and Essex, is often known as Estuary English. The term is a term for a milder variety of the "London Accent". The spread of Estuary English extends many hundreds of miles outside London, and all of the neighbouring home counties around London have residents who moved from London and brought their version of London accents with them, leading to interference with the established local accents. The term London Accent is generally avoided, as it can have many meanings. Forms of "Estuary English", as a hybrid between Received pronunciation and various London accents, can be heard in all of the New Towns, all of the coastal resorts, and in the larger cities and towns along the Thames Estuary.