Plant trees for water management

How trees and woods can reduce flooding

Although further UK based evidence is needed, there appears to be significant potential for trees and woods in the water catchment to help reduce flood risk. This is particularly the case at a local catchment scale and for moderate flood events.  Research on floodplain and riparian woodland planting suggests that trees can have a significant impact on reducing or delaying larger floods within downstream towns and cities.



Surface water runoff is the major cause of flooding in our towns and cities. The risks are increasing as more hard surfaces areas are being created, by paving over gardens and developing business car parks for example. The frequency and severity of  storms are predicted to rise as our climate changes and thus the problem of surface water flooding is likely to worsen.  However, preliminary results from research by Manchester University indicate that trees can help reduce surface water runoff by as much as 60% compared with asphalt. 

How trees and woods can reduce water pollution

Runoff from agricultural land can lead to sedimentation and pollution of watercourses, which is both damaging to wildlife but also costly due to the expense of treating the water downstream. Research shows that carefully sited trees and woods can assist infiltration of rainwater, helping reduce runoff. Reducing peak storm flows also helps to lessen the erosion of river banks, which further reduces sedimentation and the risk of localised and more widespread flooding.

Trees planted as part of riparian buffer strips in sensitive infiltration areas are also a cost-effective way to help protect rivers and aquifers from agricultural nutrient and pesticide runoff.

In urban areas, runoff not only contributes to localised flooding, it also pollutes water courses and increases water treatment costs. Collecting rainwater, planting trees and creating permeable surfaces in gardens, drives and car parks can make a significant difference in this area also.

The Woodland Trust has been working with landowners in the River Derwent catchment, helping them plant trees on land damaged by the massive floods of 2009. New trees will help stabilise banks and have the potential to slow flood water, reducing the impact of any future floods.

Read our case study

If you are interested in planting trees for water with the Woodland Trust, contact Diane Millis, partnerships manager at dianemillis@woodlandtrust.org.uk

Woods and trees can play a vital role in controlling both water quality and quantity according to a recent review of evidence conducted by Forest Research.

The Environment Agency and Forestry Commission have produced a Summary report of the research: ‘Woodland for Water: Woodland measures for meeting Water Framework Directive objectives’

Read the report