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Preventing Unwanted Flooding from Beaver Dams

Simple devices made of plastic pipe and wire fencing provide effective and economical solutions to control water levels to prevent flooding and protect roads, trails, and other infrastructure.
Flexible Pond Levelers keep ponds at acceptable levels and Beaver Deceivers protect culverts.

Flexible Pond Levelers  (TM)

Developed from earlier designs, Beaver Solutions LLC in Massachusetts has installed over 1,000 Flexible Pond Levelers in many states in the U.S. and in Canada, which have successfully regulated water levels in Beaver Ponds to prevent unwanted flooding.  Installed correctly these devices require little maintenance and continue working for decades.  Sierra Wildlife Coalition has installed several of these successfully in the Tahoe and Truckee area, for the US Forest Service, The CA Tahoe Conservancy, and for private homeowners associations.  Materials are readily available- flexible ABS irrigation pipe, concrete block (CMU) for weights, 6x6 mesh commonly used as concrete slab reinforcement - and the total cost for an installation is only about $300, with free labor provided by our Volunteers, and easily installed in an afternoon.

Installing a Pond Leveler for the US Forest Service at Taylor Creek

LIghtweight and flexible ABS pipe is put thru a notch made into the Beaver Dam at the desired water level.  The pipe is run back into the pond, away from the dam 20'-30', to an inlet protection cage made of 6x6 wire mesh.  This inlet cage prevents the pipes from getting clogged with debris, AND also prevents the beavers from feeling or hearing water going into the pipes.  Since there is no sound or moving water at the inlet or the actual dam, the beavers do not try to 'fix' it.

A few tools (and Inlet cage and CMU weights)                   The pipes (in this case, 8")                          Notching the beaver dam

Attaching the pipe to the Inlet Cage                Both pipes thru the Notch in the Dam                     Adding CMU weights to hold the pipes down

  Covering the pipes and notch with sticks                       Completed Leveler, almost invisible underwater

"Beaver Deceivers" - Protecting Culverts

Done and headed home

"Beaver Deceivers" are very specific fencing systems to prevent beavers from plugging culverts.  These were developed (and trademarked) by Skip Lisle in Connecticut - see his website at for some beautiful photos of many of his installations.


Wire-mesh fencing is installed in a trapezoid shape above a culvert - the fenced area is narrow at the culvert, and then widens going upstream from the culvert, to make a trapezoid ideally at least 15' wide.

The beavers cannot dam against the widening sides,  as the current works against them, and if the trapezoid is large enough the upper side becomes too wide for beavers to dam easily.  The bottom of the fenced trapezoid also has to be covered with wire mesh, as beavers are very good at digging.  Metal fence posts pounded into the bottom of the pond hold the fencing in place.


Mike Callahan of Beaver Solutions LLC combines a Beaver Deceiver with a Pond Leveler for an almost fool-proof Pipe and Fence System.

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