Beaver back saver how-to

Beaver Back Saver Device, Top and Side Views (Illustration by Sherry Guzzi)

These simple structures can be made by a fabricator or hobbyist welder. Installation takes 1-2 hours and is easiest under dry conditions.

Materials list:

  • Custom-fabricated three-sided connector box sized to fit the weir you are protecting
  • 10 to 20-foot long 24”-diameter HDPE culvert pipe with holes for rebar pins on both ends; pipe should be perforated 4 rows of 4-inch-wide holes with 1-foot spacing between them, making sure one of these rows is on the bottom of the pipe.
  • Custom rebar pin to secure pipe to steel cylinder on front of box
  • Concrete block with an attachment point on top (?) or a custom-fabricated metal support for pipe
  • 8-foot-long galvanized chain to secure pipe to support
  • Ask Brock about hardware to close the chain (nut, bolt, lube)
  • Hog paneling or custom-made grate sized to cover 24-inch-wide pipe inlet
  • If connector box lid does not cover weir itself, you will need to build another grate to cover the top of the weir

Tools for installation:

  • For dry installations, a backhoe; for wet installations, an excavator
  • Laser level (or other means to level concrete block with weir)
  • Rope or chain to secure device to backhoe or excavator bucket


  • Clean the twin track weir of any debris.
  • Dig out a hole or basin to accommodate structure keeping in mind that you will need enough space for the concrete block that supports the pipe.
  • Place a concrete block with the top resting at the same elevation as the bottom of the weir.
  • Slide the three-sided connector box through the outer track of the twin track weir.
  • Fit the perforated pipe onto the three-sided steel connector box, making sure one row of holes is at the bottom, and pin it to stay secure.
  • Chain the pipe onto the concrete blots blocks so the pipe couldn’t float away or move.
  • Add the hog paneling or custom grate to pipe inlet to keep beavers from coming in.
Example of a wet installation. Installer has secured pipe to a welded metal support structure.
Example of a dry installation. Installers are securing the pipe to the concrete block with a chain.