Clinton Devon Case Study

Clinton Devon Estates are one of the main landowners in the river Otter catchment, where beavers were discovered breeding in 2013 and a beaver trial run by Natural England took place between 2015-2020. This was the first officially licensed reintroduction of beavers to the wild in England.

Throughout the catchment they have constructed 28 dams at 6 locations (as of 2019). Roughly half of the land in the catchment is occupied by improved pasture, just over a quarter by arable farming, and the remainder is mostly woodland, built-up areas, and the Pebbled Heaths conservation area.

The main stem of the river is 65km long, and there are estimated to be almost 600km of watercourses in total. At Budleigh Brook near Otterton, a beaver family has constructed dams along 300m of stream, the longest dam being 60m, and created a complex wetland and multi thread channel system. Downstream of the beaver territory is a flood-prone village where 52 properties are at risk of of flooding from the brook and surface water, and there have been four flood events since 2000.

The beaver dams have created a water storage area, rewetted the surrounding floodplain, and created complex flow paths and increased the “hydraulic roughness” – the amount of obstacles for water flowing through the site. Since they were introduced, floods have been attenuated, taking longer to move through the site and having longer peak flow levels. A cost-benefit analysis in the River Otter Beaver Trial Science and Evidence Report suggest that the reduction in flood risk to properties downstream thanks to the beavers would result in a net economic benefit.