Nov 8 2006
New flood defences must be fully adaptable to the consequences of climate change and rising sea levels, according to new guidance issued today by Defra.
The guidance advises those responsible for building flood defences to plan for the long term, by factoring in increasing rates of sea level rise - a result of the climate change already locked in to the global system. Sea level rise is likely to accelerate from the current 2.5mm to 4mm a year to 13mm and 15 mm a year by between 2085 and 2115.
Climate Change and Environment Minister Ian Pearson said:
"Adapting to the consequences of climate change is already a key consideration in managing the risks of flooding. We know that sea levels are rising, and this will get worse over time. This is why we need to work with natural processes rather than against them and also ensure that those responsible for designing flood defences adapt to the long term impacts of climate change.
"The new climate change guidance will help ensure that investment decisions for new coastal defences are sustainable and based on appropriate scientific advice."
The new guidance, in line with previous climate change scenarios issued by Defra, will help authorities to calculate when and how best to build allowances for climate change and sea level rise into their flood defence plans.
Extending the timescale to be considered from 50 to over 100 years will help operating authorities examine the appropriate response to adapt to the risks and uncertainties of climate change. Authorities will consider whether it is necessary for currently planned flood defences to take account of future anticipated sea level rise, or whether to build defences now that are easily adaptable in the future. In many cases, it will be necessary to ensure that defences can be strengthened in future, to take account of increased risks.
As well as higher sea levels, unchecked climate change could lead to an increase in the intensity, severity and frequency of coastal storms and rainfall events affecting river catchments and urban surface water flooding. The new guidance also includes updated allowances for these events.
The guidance comes on the back of the Stern Review on the Economics of Climate Change , which highlighted the latest science showing that the risks of climate change could be more serious than previously thought. Long-term planning will be a key element of adapting to some of the inevitable consequences in the UK.
The Government will shortly be publishing a new planning policy statement on development and flood risk, PPS25. This will avoid inappropriate development in areas at risk of flooding, and direct development away from areas at highest risk - so lessening the future impact of climate change on flood risk.