How the Thames Barrier works, and when it is scheduled to close.
Applies to England
The Thames Barrier is one of the largest movable flood barriers in the world. The Environment Agency runs and maintains the Thames Barrier as well as London’s other flood defences.
Forthcoming scheduled closures
Planned tests of the Thames Barrier 2023 to 2024
The Barrier is operated once a month for maintenance and test purposes. Details of the next planned closures are listed below:
2 November 2023 Thursday 9:15 - 11:45 (cancelled)
4 December 2023 Monday 10:30 - 13:00
15 January 2024 Monday 9:50 - 12:20
13 February 2024 Tuesday 9:35 - 12:05
14 March 2024 Thursday 9:40 - 12:10
11 April 2024 Thursday 9:40 - 12:10
Please note these times may change as a result of a particular experiment or test that engineers need to carry out or because of the weather. The closure and reopening of the gates may start up to an hour before the listed times. Occasionally, closures may be cancelled at short notice due to the Thames Barrier being closed in that month for flood defence purposes or navigational reasons. If you plan to come and watch a test closure, call us the day before to check it is going ahead.
Please call us on 0208 305 4161 or email email@example.com for our opening times, packages prices and conference details.
The Environment Agency receives information on potential tidal surges from:
- weather satellites
- oil rigs
- weather ships
- coastal stations
They can forecast dangerous conditions up to 36 hours in advance. The barrier will close just after low tide, or about 4 hours before the peak of the incoming tide surge reaches the barrier.
Information comes from a range of mathematical computer models that forecast expected sea and river levels. This is supplemented by data from the Met Office and real-time information provided by the UK National Tidegauge Network. This hydrological and meteorological data is fed into the control room every minute from a wide network of tide and river pressure and wind gauges.
The decision to close, or not, is based on a combination of 3 major factors:
- the height of the tide (usually a spring tide) measured at the Thames Estuary
- the height of the tidal surge, which naturally accompanies each tide
- the river flow entering the tidal Thames, measured as it passes over Teddington Weir
The barrier has no individual trigger level for closure. The closing process is guided by a mathematical matrix that considers the river flow, tide and surge at the time. The final decision for closure lies with the Thames Barrier Duty Controller.
How the Thames Barrier works
The Thames Barrier:
- spans 520 metres across the River Thames near Woolwich
- protects 125 square kilometres of central London from flooding caused by tidal surges
It has 10 steel gates that can be raised into position across the River Thames. When raised, the main gates stand as high as a 5 storey building and as wide as the opening of Tower Bridge. Each main gate weighs 3,300 tonnes.
The barrier is closed under storm surge conditions to protect London from flooding from the sea. It may also be closed during periods of high flow over Teddington Weir. This is to reduce the risk of river flooding in some areas of west London including Richmond and Twickenham.
The Thames Barrier will then remain closed over high water until the water level downstream of the Thames Barrier has reduced to the same level as upstream. This is a managed process to provide for different circumstances, and takes about 5 hours. The Thames Barrier is then opened, allowing the water upstream to flow out to sea with the outward bound tide.
You can watch a video that shows how the Thames Barrier works:
Thames Barrier closures
The Thames Barrier has been closed 209 times since it became operational in 1982 - correct as at 1 November 2023. Of these closures:
- 118 were to protect against tidal flooding
- 91 were to protect against combined tidal/fluvial flooding
If you have an enquiry about the Thames Barrier, or would like to receive a project pack, email: firstname.lastname@example.org.
The future of the Thames Barrier
The Thames Estuary 2100 plan sets out how flood risk will be managed in the Thames estuary to the end of the century and beyond. It also recommends what actions the Environment Agency and others will need to take in the:
- short term (the next 25 years)
- medium term (the following 15 years)
- long term (to the end of the century)
The plan is based on current guidance on climate change, but is adaptable to changes in predictions for sea level rise and climate change over the century.
More information can be found on the Thames Estuary 2100 page.
Visiting the Thames Barrier
The Thames Barrier Information Centre is a small exhibition where you can learn about the construction of the Thames Barrier and how it works. There is a working model of the Thames Barrier and virtual technical tour along with other films and displays about flooding and the environment.
Each package has a personal guide for your group who will show you around the Thames Barrier Estate.
Our guides will cover topics including the history of the river and the risk of flooding in London, the environment and wildlife of the Thames.
Packages for group talk – available every day – need to book in advance:
- Economic package – up to 15 people, all ages - £160.00
- Child group talk – up to 30 children - £191.00
- Child luxury group talk – with activities, up to 30 children - £215.00
- Adult group talk – up to 30 people - £215.00
- Technical presentation – over 16 years old, up to 30 people - £240.00
Note there is no access on to the Barrier.
If you would like to book one of our packages, send an email to email@example.com. Note we need at least a week to process any booking form, as our guides are available just when requested.
The Thames Barrier Information Centre is open to the public every Saturday from 1st April 2023 to 28th October 2023 from 10:30 to 15:30hrs.
Adult - £5.50
Child: £4.30 – Child under 5 years old is free.
Family ticket: £15.00 (2 adults+ up to 3 children)
Our outside toilets downstairs, disabled lift and car parks will continue to be open 7 days a week between 9am and 5pm.
For further enquiries, telephone 0208 305 4161 or email firstname.lastname@example.org.
Conference room hire
The Thames Barrier View Conference Centre also has rooms to hire that offers spectacular views of the Thames Barrier and River Thames. The rooms are light and spacious and offer various room layouts to suit all occasions:
For prices, e-mail us: email@example.com.
Getting to the Thames Barrier
Charlton station is situated on Woolwich Road and is approximately a one mile walk from the Thames Barrier Site. Woolwich Dockyard station is situated near Church Street and is within walking distance. Woolwich Arsenal station is the most convenient station to take a taxi to the Barrier Site.
London Underground North Greenwich (Jubilee Line)
The station is approximately 2 miles from the Thames Barrier and only 5 minutes by taxi or bus (161 & 472).
Bus No’s 177 and 180 via Greenwich (stop at the top of Eastmoor Street). 161 & 472 from North Greenwich tube station.
London City Airport
The City Airport is situated in North Woolwich only a short distance from the North Woolwich Ferry crossing.