Trees for flood resilience

​What’s not to love about trees? They regulate the earth’s climate, clean the air of pollutants, absorb carbon dioxide and give us oxygen to breathe, provide habitat for wildlife, regulate flood waters, and much more. 

​At the Sussex Flow Initiative (SFI), we are interested in all of the benefits that trees provide, but we are particularly excited about their potential for reducing flood risk, as well as making our landscapes more resilient to drought. The benefits wheels below (taken from the Environment Agency’s Working with Natural Processes evidence base) help to illustrate just how many benefits woodlands can have across a whole range of important natural life support systems.

​The ability of trees to control flood water is the result of their importance within the hydrological cycle; intercepting rainfall, taking up water from the soil, slowing down surface run-off, and promoting water infiltration and percolation into soil and groundwater. These processes hold water on land, and reduce the amount and speed of the delivery of water to our streams and rivers. The evidence for catchment-wide woodland reducing flood flows is strong, with research able to show the negative impacts that woodland felling has at a catchment scale, on stream discharge and sediment delivery.
 
With this in mind, SFI have been making sure that we plant trees in the right places, wherever we can, to help reduce flooding. We have planted our fair share of trees throughout the Ouse catchment since the project started in 2012 – over 28,000 in fact. In December 2017, we embarked on our largest tree planting project to date – the planting of a further 12,050 trees (bringing our 2017/18 total to 17,900!) in the form of 2km of hedgerow and 1.3 hectares of woodland at the Sussex Horse Rescue Trust in Uckfield. The site is a fantastic location nestled between areas of ancient woodland and park land, with large fields sloping down to the floodplain of the River Uck – an ideal location for natural flood management enhancements, which will also provide important corridors for wildlife to move between the surrounding sites.
 
With the help and support from the local community and dedicated volunteers from the surrounding areas, we are pleased to say that we planted the last of the trees this week! With over 800 hours of volunteer time (from more than 125 volunteers), we really couldn’t have done it without them, and hopefully they will find the time to revisit the site in years to come to see the transformation once the trees are established. Working with these volunteers, and the landowner who appreciates the importance of these features of the landscape has been a fantastic experience, and we are already looking forward to next seasons planting at the site (a further 1.5km of hedgerow and more woodland areas), and reconnecting with the volunteers on other projects after a well-deserved rest.