How can Culm grassland help us to manage flooding?

In principle, wildlife habitats within a river catchment can hold back water and help to prevent flooding downstream. But how does this work in practice?

Hollocombe MoorOver the last five years, Devon Wildlife Trust has worked closely with Exeter University and other partners to examine the wider benefits of Culm grassland.

This rare habitat, a type of purple moor-grass and rush pasture peculiar to north Devon, is important for biodiversity; but it also has real potential to hold water, filter pollution and retain carbon. Understanding all of these ‘ecosystem services’ helps society to understand just how important these habitats can be.

Increasing our knowledge

StowfordResearch to date by Exeter University across a number of sites in north Devon has shown that Culm grassland can hold up to five times as much water as intensive grassland in extreme weather events.

The analogy often used is that Culm grassland acts a little like a ‘leaky bucket’, holding and releasing water more slowly than more intensive land uses. Results have also shown that Culm grassland can play a significant role in reducing nutrient pollution and storing carbon. Much of this benefit from Culm grassland comes from its uneven and tussocky vegetation layer.

We will be learning our about how Culm Grassland holds water through new Ph.D research with Exeter University, starting in 2017.

Reports about this research:

The economic value of ecosystem services provided by culm grasslands. This report describes how research data has been used to build the first ever picture of the financial value of ecosystem services delivered by culm grassland. 

Culm Grasslands Proof of Concept; Developing an understanding of the hydrology, water quality and soil resources of Unimproved grasslands. 

Putting knowledge into practice: the Culm Grassland Natural Flood Management Project

Green hay spreading tractor

Our latest project started in October 2016 and will run for four years until September 2020. It’s supported and funded by the Environment Agency (EA), Devon County Council (DCC) and the European Union through Interreg 2 Seas. Delivery is supported by a partnership of EA, DCC, Exeter University and Natural England.

The project aims to:

  1. Learn more about how Culm grassland and wet grassland can help to hold and release water in catchments (through Ph.D. research and modelling)
  2. Increase everyone’s understanding about the value of Culm grassland, and the role they can play in its protection and re-creation (through workshops and training)
  3. Work with landowners to protect, restore and re-create Culm grassland sites across north Devon (through free farm advice, grants and practical work, targeted to high flood risk areas)
  4. Share our learning with others across the South West, UK and Europe

Culm workshopUnderstanding how Culm grassland works in practice in a complex landscape will increase our knowledge and help farmers and flood risk engineers to evaluate the wider practical benefits of this important wildlife habitat. By actively managing existing habitat and creating new grassland, landowners can make a real contribution to this effort.

Our partners and funders for this developing project include:

Interreg 2 Seas


Keep in touch with the latest news on this project:

Culm Grassland Natural Flood Management Project: newsletter 1 March 2017

Contact:
Lisa Schneidau, NIA Manager
lschneidau@devonwildlifetrust.org
01409 221823