Reports from experts at the Mammal Society are suggesting that the reintroduction of beavers could help alleviate the flooding problems affecting parts of the UK. This follows a successful reintroduction in Scotland.
Beavers became extinct in the UK during the 16th century due to hunting but their dam building skills may be helpful in tandem with man-made solutions. In fact their reintroduction could be as useful as dredging and erecting flood barriers.
Society Chief Executive Marina Pacheco stated that the river systems are in a poor state, which needs to be acknowledged, and that special help is needed to get the floods under control. She is advocating the reintroduction to start in the most flood prone areas to see their most immediate benefits.
Results
Beavers have been reintroduced in Scotland since May 2009 and are what is known as a ‘keystone’ species. This is because their dams create ponds and wetlands which can attract other species. Studies also suggest that the wetland can hold around 40 times as much water when worked by beavers.
Beavers work on the rivers and re-establish more natural environments which retain water behind their multiple small dams. This water is then release at a slower rate than man-made drains currently do.
They also create tributaries and side streams which can reduce the pressure on the main river. This could help ease the flooding downstream and would be a very cost effective measure.
Dredging
The current most commonly suggestion solution for the flood prevention is the dredging of the rivers worst affected. However Ola Holmstrom, UK Head of Water at consultancy firm WSP, was quoted as saying that dredging is ‘hotly debated as a flood risk mitigation measure within the hydrological community’. Experts say that the river channel only has small water storage compared with the flood plain and removal of material does increase capacity but not significantly.
And while the currently used system of getting the water to the ocean as quickly as possible still has its merits, problems are simply being moved along the drainage route. Improving the movement of the water through one place can simply increase the risk of flooding down the line at another.
The suggestion is to focus on the upstream areas and increase the capacity to hold water there. This comes with the benefit of being substantial more cost efficient than dredging.
Flood plains
Ultimately it may come to the point where flood plains are reverted to just that and not used for housing or farming. With the changes in the climate, it may come about that there is simply no easy solution to fix the problem in certain areas such as the Somerset Levels, which is nearly totally below sea level and has seen horrific flooding.