UK Environment Agency publishes new evidence to plan for flood and coastal risk up to 2065
The Environment Agency has published a new economic assessment to aid planning for flooding and coastal risk management over the next 50 years. The long-term investment scenarios use new climate change, population and mapping data to set out potential future scenarios, assessing how funding could be best allocated to meet these challenges.
(published 28 February 2019)
Under a plausible extreme climate change scenario (IPCC A1FI), there are more places where new investment is not cost effective.
In the high climate change scenario and with current effective planning outcomes it’s possible to prevent risk from increasing.
Conventional investment strategies suggest an overall cost benefit ratio of 5 to 1 i.e. for every £1 invested about £5 of property damage would be avoided.
With optimum investment and outcomes in this new study, that ratio increases 9 to 1.
Using strict economic criteria alone and not considering the social impacts, assets would be left to degrade. This would increase risk.
Using a potential new method to calculate the benefit cost ratio for a flood risk management scheme the impacts on mental health increase from 16:1 to 24:1.
Building and maintaining large-scale engineered defenses, using natural flood management techniques such as planting trees and slowing the flow of water, and property flood resilience for homes will be required.
Planning policy mitigation measures can reduce risk to properties on flood plains, for example, raised floor levels.
It is not just property at risk from flooding. Transport and utility networks are at risk (41%) requiring protection investment.
The Environment Agency is investing £2.6 billion in flood and coastal erosion risk management projects between 2015 and 2021, helping to protect 300,000 homes.