Editing River Thames (section)

===20th century===
[[File:London from above MLD 051002 003.jpg|thumb|The Thames as it flows through east London, with the [[Isle of Dogs]] in the centre]]

The growth of [[road transport]], and the decline of the [[British Empire|Empire]] in the years following 1914, reduced the economic prominence of the river. During the [[Second World War]], the protection of certain Thames-side facilities, particularly docks and water treatment plants, was crucial to the munitions and water supply of the country. The river's defences included the [[Maunsell fort]]s in the estuary, and the use of [[barrage balloons]] to counter [[Luftwaffe|German bombers]] using the reflectivity and shapes of the river to navigate during [[the Blitz]].

In the post-war era, although the [[Port of London#The Port today|Port of London]] remains one of the UK's three main ports, most trade has moved downstream from central London. In the late 1950s, the discharge of methane gas in the depths of the river caused the water to bubble, and the toxins wore away at boats' propellers.<ref>Peter Ackroyd "Thames: Sacred River" 274</ref>

The decline of heavy industry and tanneries, reduced use of oil-pollutants and improved sewage treatment have led to much better water quality compared to the late 19th and early- to mid-20th centuries and aquatic life has returned to its formerly 'dead' stretches.

Alongside the entire river runs the [[Thames Path]], a National Route for walkers and cyclists.

In the early 1980s a pioneering flood control device, the [[Thames Barrier]], was opened. It is closed to tides several times a year to prevent water damage to London's low-lying areas upstream (the [[1928 Thames flood]] demonstrated the severity of this type of event).
[[File:A London Mosaic.jpg|thumb|A view of the Thames as it passes through London, composed of 29 photos taken from the ISS in 2021]]
In the late 1990s, the {{cvt|7|mi|km|0|adj=on}} long [[Jubilee River]] was built as a wide "naturalistic" flood relief channel from [[Taplow]] to [[Eton, Berkshire|Eton]] to help reduce the flood risk in [[Maidenhead]], [[Windsor, Berkshire|Windsor]] and Eton,<ref>[[Environment Agency]] (2005). ''[http://www.environment-agency.gov.uk/subjects/recreation/345623/631029/346131/348128/349190/349293/?lang=_e&theme=&region=&subject=&searchfor=Jubilee+River&any_all=all&choose_order=&exactphrase=&withoutwords=&exclude_itemtype=Station%2C&include_itemtype=Acrobat%20Document%2CAttached%20File_e%2CAttached%20File_w%2CHTML%20Page%2C Jubilee River] {{Webarchive |url=https://web.archive.org/web/20100225045649/http://www.environment-agency.gov.uk/subjects/recreation/345623/631029/346131/348128/349190/349293/?lang=_e&theme=&region=&subject=&searchfor=Jubilee+River&any_all=all&choose_order=&exactphrase=&withoutwords=&exclude_itemtype=Station%2C&include_itemtype=Acrobat%20Document%2CAttached%20File_e%2CAttached%20File_w%2CHTML%20Page%2C |date=25 February 2010 }} ''.</ref> although it appears to have increased flooding in the villages immediately downstream.