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Beavers build 70 metre wide dam (believed to be the largest beaver-made dam in the UK) across Sutherland Beck in Cropton Forest\u2013 slowing the flow and reducing flood risk for the village of Sinnington downstream.<\/h3>\nBeavers build 70 metre wide dam (believed to be the largest beaver-made dam in the UK) across Sutherland Beck in Cropton Forest\u2013 slowing the flow and reducing flood risk for the village of Sinnington downstream.<\/h3>\n<\/p>\n
Yorkshire and Humber Climate Commission writes:<\/p>\n
Cath Bashforth, ecologist at Forestry England, gives\u00a0an insight into the Yorkshire enclosed beaver release trial.<\/p>\n
What work are you doing?<\/strong> How does this trial relate to improving climate resilience? What are the aims of the trial? Other aims of the project include assessing the additional amount of water retention and how the water moves through the site, the beaver\u2019s impact on biodiversity within the enclosure and also their effect on rhododendron.\u00a0 It is also hoped further into the project that the potential for ecotourism can be investigated.<\/p>\n How do you monitor the impact of the beavers? Over 40 volunteers have been involved, surveying plants, bats, small mammals, otter, amphibians and reptiles, mosses and liverworts, butterflies, dragonflies, diptera and fungi.\u00a0 The volunteers were invaluable in pulling together a fantastic baseline of information of site biodiversity and this will be monitored throughout the 5 years of the trial.<\/p>\n We also monitor the beavers closely with 12 trail cameras throughout the enclosure to capture footage of behaviours and monitor their health and wellbeing.<\/p>\n What water engineering have the beavers done so far? In addition, the beavers have built a large dam in the river which is now over 6ft tall.\u00a0 This has significantly raised water levels upstream to enable them to burrow into the banks and create an\u00a0underwater entrance into their lodge, which they have constructed on the river bank.\u00a0 They have since extended this dam across the floodplain, connecting the pond and the river, and built up the bottom pond edge by 30cm along its whole 60m length to hold back even more water, significantly changing the way the water moves through the site.<\/p>\n So far the beavers have not worked on the man-made structures \u2013 but it is early days yet.<\/p>\n Have the beavers slowed the water flow? Early results from Exeter University\u2019s monitoring show that the beavers\u2019 structures do indeed seem to be helping to reduce the peak of the water flow through the site, although it is still too early in the project to be conclusive.<\/p>\n How have beavers impacted on biodiversity?<\/strong> The beavers have also coppiced many of the trees overhanging the pond – opening it up to a lot more light.\u00a0 This has seen foxgloves and other vegetation appearing along the pond banks which were not growing here before due to the amount of shade.\u00a0 The willow trees are already coppicing back up with abundant shoots \u2013 a future resource for the beavers.\u00a0 Interestingly many of the stems were \u2018pleached\u2019 (left attached) and fell into the water meaning that the shoots that grow will be much more accessible to the beavers going forward \u2013 was this accident or planning?<\/p>\n
\nIn April 2019, 2 adult beavers from Scotland were released into an enclosure in Cropton forest as part of a 5 year trial. The enclosure is securely fenced and is just over 10ha in size, it is situated in the river Seven catchment.<\/p>\n
\n<\/strong>The stream rises and falls very rapidly and was part of the \u2018slowing the flow\u2019 project which started in 2007 to look at the impact of man-made woody dams reducing the peak during storm events.\u00a0 This earlier project had been established in an effort to reduce flood damage in Pickering and Sinnington downstream.<\/p>\n
\n<\/strong>The main aim of the trial is to monitor the way that the beavers interact with the man-made woody structures in the beck – to see if they will adopt and maintain them on our behalf.\u00a0 There is one large timber bund in the site and 3 smaller man-made dams.<\/p>\n
\n<\/strong>Exeter University have been working on the hydrological monitoring of the watercourses and also undertaking aerial drone imagery.\u00a0 Leeds University have been involved with laser scanning several areas and Teesside University have undertaken aquatic vegetation surveys.<\/p>\n
\n<\/strong>The 2 beavers have quickly made the site home.\u00a0 They set to work straight away plugging the leaks in the top pond and the water levels have now increased by over a metre in both ponds.\u00a0 The beavers constructed an amazing canal to connect the bottom pond to the top pond.\u00a0 Beavers move much more easily in water and feel more comfortable, so this was to aid their travel between the ponds.<\/p>\n
\n<\/strong>Now, water is forced out across the floodplain in periods of heavy rain instead of rushing down the river channel, resulting in a multi-braided watercourse which effectively slows the flow.<\/p>\n
\nTheir work has resulted in a record amount of amphibians recorded at the site. Before the beavers were released just 6 clumps of spawn were recorded, this year the amount of spawn was uncountable.\u00a0 Because of the number of frogs and toads over 12 herons have been regularly seen fishing around the pond and both otters and tawny owls have been caught on camera feasting on the amphibians.\u00a0 \u00a0\u00a0Teal and Mandarin have been spotted on the site for the first time too because of the increased water levels.<\/p>\n