Beavers may be used to combat pollution
The project at Roadford Lake, West Devon, is being considered by South West Water (SWW) to prevent harmful blue-green algae from forming. The reservoir supplies drinking water to much of the Westcountry.
Introducing beavers to the water, say SWW managers, would lead to the creation of naturally formed damns which would filter out the pollutants from run-off that cause the algae to form.
It is currently illegal to release beavers into the wild without a licence. A feasibility study is being carried out to see if one should be issued for Roadford Lake. The project is a multi-agency scheme including Natural England, SWW and the Derek Gow Wildlife Consultancy.
The scheme has been opposed by residents who say they fear their land could be at risk from flooding.
Chris Durston, who has land bordering the area, said: "My land is very low-lying and there is a very real risk that I could lose it to flooding caused by beavers building a dam.
"I don't think they have thought through the consequences of reintroducing something that has not been here for many hundreds of years."
SWW has been working closely with Mr Gow, a wildlife consultant who lives close to Roadford Lake. He said while there were no "done deals" on the matter, it was likely landowners would be given financial incentives for allowing some of their land to become waterlogged.
He said: "Beavers pose no risk to humans and they are very good for the local biodiversity. By allowing them to cut back trees on the water's edge, they allow light in, which helps to encourage an abundance of plant and wildlife.
"People concerned about their land flooding would have no problem. There would be no rules protecting dams built – it will be possible to take them down."
He said reintroducing beavers would also help the water vole population, which finds it very hard to nest anywhere because of the amount of trees on river banks.
Mr Gow said: "In this time of heavy recession, we can't really be looking at anything that will discourage tourism. If we have beavers in the water, then there is every likelihood that people will want to come to the area."
SWW uses an electrically powered oxygenation system which prevents the algae from forming on water in its reservoirs, but it will not prevent the natural, but potentially lethal, pollutant from forming indefinitely.
Martin Ross, the firm's environmental manager, said: "The run-off from fields is causing nutrient enrichment in the reservoir. This can lead to the formation of blue-green algae making the water very difficult to treat in order for it to be suitable to be used as drinking water. This algae is toxic to dogs.
"We could continue using the oxygenation process, but this will cost a lot of money – a cost that would have to be reflected in customers' bills. Alternatively, we can reintroduce beavers, which have no pension plan, holidays or sickness and no health and safety issues in the workplace to consider."
