Planting productive woodland in specific areas of the UK could reduce the risk of flooding, according to a new landmark report. The study by Forest Research and trade body Confor highlights the role productive woodland can play in lessening the likelihood of floods – as well as offering significant potential improvements to the water environment and a range of additional economic and environmental benefits. The report draws on ‘opportunity mapping’ work Forest Research has developed to identify, map and target areas where woodland could have the most positive impact to reduce flood risk.
The report notes that forests and woodland can reduce flooding in several ways:
- The greater water use of trees reduces flood volumes
- The higher infiltration rates of woodland soils reduces rapid surface run-off of water, reducing flood generation
- The ‘hydraulic roughness’ of trees, shrubs and large woody debris acts as a drag on flood waters, slowing flows
- Trees protect soil from erosion, decreasing the amount of sediment going into watercourses and reducing the need for dredging.
It also highlights how productive woodland can deliver specific benefits, including:
- Water use tends to be highest for productive conifer woodland
- Drier soils under productive woodland may make them better able to receive and store rainfall
- In general, larger areas of planting offer greater water benefits – and productive woodlands tend to be on a larger scale because they are more economical and attractive to landowners.
- Reducing pollutants in the water
Dr Tom Nisbet, of Forest Research, the author of the report, said: “There is growing recognition that we need to develop a more sustainable approach to flood management involving a greater use of natural processes. Productive woodlands can be very good at reducing and slowing down flood flows, as well as helping to reduce the amount of soil and other pollutants entering our rivers.”
The report, titled “Role of Productive Woodlands in Water Management", is available for download from the Confor website.