Plymouth Green Minds Natural Flood Management and Beaver Project Hydrological Monitoring Report 2024
We are pleased to share the University of Exeter’s 'Plymouth Green Minds Natural Flood Management and Beaver Project Hydrological Monitoring Report 2024'. The report follows 5 years of river level monitoring and data for the Bircham, Forder and Seaton rivers - both pre and post Natural Flood Management and beaver reintroduction.
This report represents a unique, innovative urban case study and a brilliant legacy of Plymouth’s Green Minds Project. Click here to download the report.
The headline is that by slowing-the-flow with the re-introduction of beavers and installation of leaky dams (and other Natural Flood Management interventions) throughout the catchment we have reduced the impact of flooding peak flows – by a whopping 23%!
This report is the result of a lot of hard work from the University of Exeter, multiple Plymouth City Council teams including Green Minds, the Poole Farm Team and volunteers, and Plymouth Natural Grid, and Devon Wildlife Trust and The Plymouth Beaver Project Steering Group.
Summary:
1.Hydrological monitoring results from November 2019 to February 2024, conducted by the University of Exeter for the Plymouth Green Minds project, revealed significant changes.
2. Initially focused on beaver engineering, the project shifted to include natural flood management (NFM) with the installation of leaky dams, expanding the scope.
3. Monitoring extended to the neighbouring Seaton stream, now impacted by NFM interventions, adopting a before-after experimental design across all sites.
4. Continuous water level recording and rainfall radar data analysis facilitated the extraction of over 400 storm events per site, revealing reductions in peak flow levels and lag times post-NFM interventions.
5. Regression analysis indicated statistically significant peak flow reductions (23% on Bircham Stream, 11.6% on Seaton Stream), emphasising the increasing impact of NFM interventions + beavers. There is potential for further hydrological improvements as interventions continue and beavers establish.