Beavers build dams using mud and twigs to create calmer water habitats and a new study shows they can help slow flooding, according to a Science News article. Previously, researchers did not believe beaver dams had much effect on floodwater storage.
However, University of Saskatchewan researchers’ observations of beaver dam impacts during flooding has led them to believe that the dams can serve as natural flood protection. They found that the dams held nearly 4 to 20 inches of rain back, slowing and limiting the water surging into one stream.
Another damaged dam still managed to block nearly 6 inches of water in spite of a breach almost 33 feet wide. The researchers say officials should consider encouraging beaver dam expansion in flood prevention efforts.