Guide on natural flood management points to monetary gains over engineered approaches

The Construction Industry Research and Information Association has published guidance in a bid to boost implementation of natural flood management (NFM) claiming it can promise substantial monetary gains.

Natural flood management lead at Mott MacDonald and lead author of the manual, Emma Wren, said: “This is a practical guide designed to drive implementation of NFM, moving the industry from why to how.”

She claimed that financial benefits arising from natural methods “Often will exceed the flood risk benefits.” She offered an example in a Mott MacDonald project with Eddleston Water: “We found that the annual monetised flood risk benefit from the introduction of various NFM features over a 70 square kilometres catchment was about £32,000, whereas the value of the co-benefits was close to £141,000 a year.”

According to Mott MacDonald, natural solutions include “restoring bends in rivers, changing how land is managed so soil can absorb more water, floodplain restoration, installing leaky barriers, planting trees along rivers, catchment woodland and offline storage areas.” Wren added: “We try to mimic what occurs naturally. At the same time, we want to protect our rivers and landscapes from further degradation."