Looking specifically at flood plains, increasing the diversity of these can help to slow the flow of water across them when the river does flood out. A flood plain entirely comprised of just of short grazed grassland does not provide much ‘roughness’, and it is this ‘roughness’ – be it large boulders, scrub, trees, walls or hedges – which can slow the speed of the water down as it flows over the flood plain.
Increasing the complexity of the floodplain can help reduce the speed at which flood water hits communities, and the amount of debris is carries. The best way to do this would be to plant swathes of woodland across our valley bottom land – but this is an unrealistic option – floodplains in Cumbria are prime agricultural land. What can be done is to think about flood plains as a patchwork quilt, the more different patches there are, the slower the water will move and the less debris it will carry.
This is willow cropping fit in, creating another different ‘patch’ on that patchwork quilt of a flood plain. Environment Agency Energy crops and floodplain flows report Project Summary SC060092/ S2 concludes that the dense nature of the mature SRC Willow plantation acts like a ‘green leaky dam’ to hold water back within and immediately upstream of the energy crop plantation, and to slow the speed of water spread across the floodplain.