29 April 2009

Environment Agency - Home

The future

The Thames Barrier and Associated Defences were originally designed to protect London to a standard of 1:000. That is, it protects against a tidal flooding event that has a 0.1% annual probability of occurring. At the time of design and construction it was designed to protect to this standard until the year 2030 with a slowly decreasing standard thereafter.

The protection was designed with an 8mm sea level rise per year in mind. It is now known, through new techniques and methods, that sea level rise, are in the region of 4 - 6mm per year.

Present and future sea Level rise:

 Years  1990 to 2025  2025 to 2055  2055 to 2085  2085 to 2115
 Net Sea Level Rise (mm/yr) in SE England  4.0 8.5   12.0  15.0

(Source: PPS 25 - Planning Policy Statement 25: Development and Flood Risk: crown copyright)

If nothing’s done to improve the estuary’s tidal defences, the level of protection would gradually decline as sea levels rise.
We have a project a named Thames Estuary 2100 that is studying options to manage flood risk in the Thames estuary up to 2100.

Our studies will decide what standard of protection is needed for London and the Thames Estuary for the next 100 years. We will also recommend how the system of defences we’ve got at the moment may change in the future.

As well as using more traditional defences, like flood walls and embankments, we’re looking at whether we can use other methods of protection that work with the natural processes of the river. These include setting back defences to allow the river to expand in times of flood, or allowing flood waters to spill in a controlled way onto storage areas placed in the natural flood plain.

We’ll also look at the implications of closing the Barrier more often. If the present sea level forecasts are accurate there could be as many as 30 closures or more a year by 2030; this is in contrast to a current average of 4 – 5 closures per year.


Reducing Flood Risk in the Future
Reducing flood risk is not just about adapting London and the estuary’s flood defences. We also need to make sure that, in the unlikely event of a flood, people are safe. This means working with developers and local authorities to make sure new developments are in lower risk areas, are more resilient to flood and have appropriate flood warning and emergency planning.

So, the future will involve close cooperation between ourselves, government, local authorities, environmental organisations and others, to provide long term answers on flood risk management in the Thames Estuary.

Early indications suggest that the Thames Barrier will maintain the current standard of protection to the year 2070. The Thames Estuary 2100 project is investigating the many different future scenarios from minor to extreme sea level rise and proposing a number of options for numerous possible futures. Final results of this study will be available April 2009 when it goes to public consultation.

Follow the link below for more information: