Hedgerows: flood defence heroes

Prolonged heavy rainfall in winter 2023/24 has seen large parts of Bedfordshire face flooding. 

Rivers including the Great Ouse and the Flit burst their banks. In many places the saturated ground couldn’t absorb any more water and new lakes formed.

Later this year CPRE Bedfordshire will be launching the Bedfordshire Hedgerow Project which will work on planting and restoring hedgerows with a number of different groups from across the county. There are many reasons to love hedgerows, they provide homes for nature, look beautiful and capture carbon. However, an underappreciated benefit of hedgerows is their role in flood prevention. They do this in a surprising variety of ways.

Hedgerow cover helps to intercept rainfall, so that it hits the ground with less force and doesn’t run off so readily. Hedgerows slow the speed at which water moves across the surface of the ground, giving it more time to soak into the soil. This also reduces the effect of soil erosion, allowing any sediment that’s been moved by the water to settle out. The sediment doesn’t then end up in our rivers and streams.

The roots of hedgerow shrubs and trees help water to penetrate deeper into the ground, reducing runoff. Crops have shallower root systems and can’t remove water from the soil as quickly.

This all suggests there are clear benefits of healthy hedgerows on rural and farm land, but what about in more urban areas?

A 2016 survey by the RHS suggested one in four UK front gardens are paved over and nearly one in three front gardens have no plants, meaning that rainwater can’t permeate the ground. When rainwater has nowhere to go, flash flooding becomes much more likely. Planting hedges can help soak up water and slow down the flow, as well as providing other benefits such as food and shelter for declining bird species, noise reduction and improved air quality.

We’ll be exploring more of the benefits of hedgerows, their history and place in our local landscape in future posts so watch this space.