Beavers Northwest specializes in non-lethal management options to alleviate flooding and property damage without harming beavers. The most common methods are flow devices, including pond levelers and exclusion fencing. Both types of devices, when properly installed and maintained, are the most cost effective and longest lasting beaver management methods.
If you have further questions about device installation and maintenance or are interested in having us assess the feasibility of a device on your property, please contact us.
A pond leveler is simply a pipe through a dam. The pipe is set at a height that prevents further flooding, but retains enough water so that beavers can remain onsite. A cage is placed around the inlet of the pipe to prevent beavers from plugging it with mud and sticks. These devices require very little maintenance (3-4 check-ups per year), and can last indefinitely.
Deciding where to place your leveler is an important step. If you lower the pond too much, beavers will take notice and may begin building in new places which will exacerbate the problem. But if you don't lower it enough, the flooding issue will not be resolved. Finding the perfect pond height can be tricky! Note: if you remove the dam or notch it too often, beavers may move it to another spot which may be better or worse for flooding!
We notch the dams to the height that we want the pond to equilibrate. During storm events, the water level will temporarily increase until the pipe is able to convey enough water out of the pond. This is normal. The pond height should reach the desired level after a day or two.
It is important to notch the dam gradually. Releasing too much water quickly can cause problems downstream, create high sediment loads, and impact fish in the system.
Each pond leveling device consists of a pipe that goes through the dam and a cage around the inlet of the pipe. The cage is designed so that beavers cannot plug up the pipe with debris. We build these cages out of cattle panel fencing with 4" x 6" mesh. We use two of these panels to build the cages on site. Each cylindrical cage has a top and bottom to ensure that beavers cannot get in.
A hole is cut in the side of the cylinder to send the pipe through. It is important that the pipe is secure in the cage and that there is not a large gap where the pipe enters for beavers to get through.
The cage should be placed in the beaver pond upstream of the dam by at least 10 feet. If the cage is too close to the dam, beavers may key in to the water flowing through the pipe and try to plug up the cage. It is also important that the pipe is placed low enough in the cage that it will not be at the surface of the water. Any noises that the pipe makes as it draws in water will attract beaver attention.
The height of the pond with a functional device is determined by the placement of the pipe in the dam, not it's placement in the cage. This means that if you place the pipe low in the cage, it will not drain all the water from the pond unless the pipe is also placed low in the dam.
The pipe and cage should be secured with crossed t-posts to ensure that they remain in place. Depending on the site and the velocity of the water, we typically place 6-12 t-posts along the whole length of the device. If the water is too deep to safely install t-posts, cinder blocks can be used to weigh down the pipe.
To ensure that the pond leveling device can function indefinitely, periodic maintenance is required. Maintenance includes monitoring for changes in beaver activity, ensuring that the pipe remains clear of debris, and adjusting the height of the pipe in the dam to modify the pond height.
With periodic check-ups, these devices will continue to convey water and maintain the beaver pond at the desired height. We provide maintenance contracts and/or training to clients as part of our device installation. If you have questions about device maintenance at your site, please contact us.
Also known as 'beaver deceivers', exclusion devices keep beavers from plugging culverts and other narrow constrictions. Using fencing materials, beavers are kept a sufficient distance away from the culvert to reduce noise and the feeling of quickly moving water, two things that trigger beavers to build dams. By excluding beavers from this area, they are less compelled to dam the area and focus their work in more preferable places of the stream, away from infrastructure.
Exclusion devices can also be placed on existing dams. This is done by notching (removing a given amount of material) from a dam to promote water flow and achieve desired water levels. Fencing material is then placed around this gap, creating a break in the dam that beavers cannot repair. This allows continuous water flow even if beavers work along the edges of the fence. It also promotes beavers to start building in other areas that do not maximize flooding.