How Do We Prevent Flooding? Save the Beaver!
The flooding seen across the north of England and in Scotland this winter has left a trail of destruction and provoked a lot of controversy. Flood management systems failed and left thousands of people’s lives severely disrupted. Flood management is clearly a key concern for government in the coming year, but one facet to the solution could well be a species that has been absent from the UK for 400 years.
The last beavers disappeared from England in the 12th century; a small population clung on in Scotland but had also been driven to extinction by the 16th century, as a result of hunting for their fur and meat. However, in recent years there have been several programmes to reintroduce beavers to the UK. One such programme has been running on the River Otter Devon. Beavers were introduced to a three hectare patch of Woodland near Okehampton five years ago. Since then the beavers have been tree toppling and channel digging and dam building with great effect.
Biodiversity in the area has been greatly improved by beaver activity, the river has been transformed into a complex braided stream which supports a much greater diversity of wildlife including bog pimpernel, orchids and kingfisher to name a few. In addition more mayfly and caddisfly larvae have been recorded, suggesting that water quality is improving as the beaver’s dams filter out impurities washed into the river from intensively managed grassland upstream.
However, one of the most interesting aspects of the reintroduction of the beavers is their capacity to engineer the environment to better cope with flooding. The 13 dams built along a 150 metre stretch of river have formed a staircase which contain sudden heavy rainfall by releasing the water slowly, preventing the inundation that would otherwise occur if the water were simply channelled downstream. The dams have evened out the flow of the river and increased its storage capacity. Professor Brazier from the University of Exeter told the Guardian that stream that previously could only hold a few hundred litres could now hold around 65,000 litres as a result of the beaver activity.
A carefully managed beaver population could have clear benefits to flood management and water quality in areas where they have been reintroduced. However, there is still great opposition to the reintroduction of beavers. Populations would need to be managed with the utmost caution to prevent damage to land. Yet the signs from early reintroduction trials seem positive in terms of what beavers could bring to the UK.
Source: The Guardian