I think we shouldn’t be trying to solve problems once created we should be stopping them at the root cause. Is it possible that what’s happening here is the water is being rerouted for a very specific reason? And that there is more to the reintroduction of the beaver population than meets the eye? Like I said there was a reason these beavers were culled to begin with.
Beavers weren't "culled" @LemaLemons. They were hunted to extinction because:
a) they are really tasty and people like eating them.
b) they have really thick fur that kept people warm before central heating came along so people liked killing them to wear them.
c) the secretions of their anal glands were used in medicine and perfume so people liked killing them to make themselves smell better and feel better.
And as far as water rerouting is concerned, it's worth educating yourself on what happened when people straightened rivers. Rivers are not naturally straight. It was very fashionable to straighten rivers and then, suddenly, people realised that the water comes down a straightened river really, really fast and then, shock horror, it floods. So having watercourses "re-meandered", as it's known, is a really good flood prevention tool. You'll probably go off now and look to see what a meander is and whether it'll need culling or if it'll attack children. The answer is almost certainly.