Clients: Natural Resources Wales
Year: 2025
eftec team: Ian Dickie, Allegra Naldini, Emma Thomas
Service Area: Ecosystem service valuation
Location: Wales
Full report: Spatial mapping of the role of coastal habitats in mitigating flood risk in Wales
Flooding from the sea poses increasing risks to communities, infrastructure and economic activity along the coastline of Wales. While engineered defences are often the focus of flood management, natural habitats such as saltmarsh, dunes and shingle also play a protective role.
Economic analysis needs clear evidence of the ability of natural habitats to reduce flood risk to justify long-term investment in maintaining and restoring such habitats. eftec and ABPmer were commissioned by Natural Resources Wales (NRW) to find that evidence. We asked:
What is the economic value of natural flood protection?
How much flood damage is avoided because the habitats that are present?
Where are these benefits greatest?
Our analysis shows that coastal habitats in Wales provide an estimated £36 million per year (2025) in avoided flood damages. Nearly half of this value (48%) comes from avoided damage to residential and commercial properties. A further 37% results from reduced disruption to rail services, with additional benefits linked to avoided impacts on agricultural land and roads. Where dune systems and saltmarsh are extensive and functioning well, the reduction in flood damages is particularly significant.
The findings demonstrate that coastal habitats are economically critical infrastructure.
To reach this headline figure, the project team:
Mapped 380 Coastal Units around Wales to identify where natural habitats contribute to flood protection.
Applied an ecosystem accounting framework to link habitat characteristics (such as dune height and saltmarsh extent) to flood attenuation.
Translated flood attenuation to avoided damages to properties, agricultural land, roads and rail infrastructure in the protected areas.
Developed an innovative approach to assess how habitat protection reduces disruption across interconnected rail corridors.
Valued avoided damages using economic data on property losses, agricultural impacts, travel time costs and compensation payments for disrupted rail services against a counterfactual.
By identifying where coastal habitats deliver the greatest economic benefits, the results support more effective investment in their maintenance and restoration. Our work strengthens the case for nature-based solutions alongside engineered defences.
As flood risk increases, integrating natural infrastructure into mainstream decision-making will become increasingly important. This study provides the foundation to do so. Future work on other natural habitats and integrating increasing flood risk due to climate change into projections, will support decision making for other investments in nature too.