MIL-OSI United Kingdom: Growing evidence of the benefits of natural flood management

Working with natural processes (WWNP) or natural flood management (NFM) protects, restores or emulates the natural functions of rivers, floodplains, catchments and the coast to reduce flooding and coastal erosion.   

The updated Working with natural processes evidence directory was published in February 2025. It summarises the latest evidence for 17 NFM measures relating to river and floodplain, woodland, run-off, and coast and estuary management.

The directory shows NFM evidence has grown in recent years, building our confidence in the flood risk and wider benefits these approaches can bring.   It provides a new evidence baseline for NFM, helping to inform future investment decisions and support the selection of measures on the ground.

These benefits vary across measures and help us understand what works best and where. There is still more to learn about NFM, but the research gaps are closing and are becoming more detail orientated.  

Among the findings, the evidence is telling us that:

• catchment woodlands can reduce the height of flood water, with the greatest reductions during smaller events
• there is growing research that soil and land management can help with flood resilience, especially in grasslands
• for some NFM measures, the wider benefits are even greater than the benefits to flood risk such as with floodplain or river restoration
• ponds in floodplain areas can reduce flood risk by decreasing flows and storing water
• run-off pathway management can reduce flood risk by storing water, and slowing the flow downstream and includes wider benefits related to water resources and biodiversity
• the flood risk benefits of saltmarsh and mudflat restoration, dune management and beach nourishment is consolidating 
• restoring salt marshes and mudflats offers significant environmental benefits including storing carbon 
• there is emerging science on the flood reduction benefits of beavers, coastal reefs, and submerged aquatic vegetation – these are new additions to the directory

Further details about the findings are available in the Working with natural processes research report and literature review.

Quick guides for each of the 17 NFM measures covered in the evidence directory are included on the summaries page.