How Beavers Build Dams

For 20-million years, beavers have been nature’s water engineers.

In North America – before Europeans trapped them out – 400-million beavers impounded 50-million surface acres of water. Beaver eradication was a disaster for continental hydrology. Fortunately, they can be restored. Beavers can again work tirelessly, cheaply and effectively to maintain and improve watersheds.