The use of a three-log drain or a structural device such as wire mesh culverts or T-culvert guards will occasionally cause beavers to move to other areas. They all prevent beavers from controlling water levels. However, once beavers have become abundant in a watershed or in a large contiguous area, periodic reinvasions of suitable habitat can be expected to occur. Three-log drains have had varying degrees of success in controlling water levels in beaver impoundments, especially if the beaver can detect the sound of falling water or current flow. All of these devices will stimulate the beavers to quickly plug the source of water drainage.
A new device for controlling beaver impoundments and keeping blocked culverts open is the Clemson beaver pond leveler. It has proven effective in allowing continual water flow in previously blocked culverts/drains and facilitating the manipulation of water levels in beaver ponds for moist-soil management for waterfowl and other environmental or aesthetic purposes. The device consists of a perforated PVC pipe that is encased in heavy-gauge hog wire. This part is placed upstream of the dam or blocked culvert, in the main run or deepest part of the stream. It is connected to nonperforated sections of PVC pipe that are run through the dam or culvert to a water control structure downstream. It is effective because the beavers cannot detect the sound of falling or flowing water as the pond or culvert drains; therefore, they do not try to plug the pipe. The Clemson beaver pond leveler works best in relatively flat terrain where large volumes of water from watersheds in steep terrain are not a problem.
A number of improvements have been found with beaver pipes. Before looking any further into this, you should consult your state’s wildlife officials to determine what permits may be needed. Beaver ponds are often considered wetlands, and you don’t want to run afoul of wetlands laws.
In states where trapping is legal, trapping can be an effective method of reducing beaver numbers and flooding associated with beavers. Check with your state Department of Natural Resources for regulations concerning beaver trapping.
Resources: (online)
ICWDM
Beavers
Beaver Pipes
