Beavers are the largest living rodents in North America, with adults averaging 40 pounds in weight and measuring more than 3 feet in length including the tail. Once among the most widely distributed mammals in North America, beavers were eliminated from much of their range in the late 1800s because of unregulated trapping and loss of suitable habitat. Today, interest in Living with Beavers in California is on the rise as the benefits to fish and wildlife habitat, surface water storage and ground water recharge become more apparent during drought conditions.
Because the activities of beavers can create conflict with wildlife, agriculture, infrastructure or human safety, the Department does not issue permits for the relocation of beavers in California. Please consider living with beavers to help support California beaver populations and their benefits to terrestrial and aquatic habitats.
Beavers are well known for their construction efforts. They create dams and lodges for shelter and protection, largely with woody material. This woody material is either gathered from the ground locally or from small and medium-sized trees that the beavers fell with their teeth.
Beaver dams create habitat for many other animals and plants of California. Deer and elk frequent beaver ponds to forage on shrubby plants that grow where beavers cut down trees. Weasels, raccoons, and herons hunt frogs and other prey along the marshy edges of beaver ponds. Sensitive species such as red-legged, yellow-legged and Cascade frogs all benefit from habitat created by beaver wetlands. In coastal rivers and streams, young coho salmon and steelhead may use beaver ponds to find food and protection from high flows and predators while waiting to grow big enough to go out to sea.
Tips for Preventing Conflicts
Beaver activities can cause problems, but before beginning a beaver control action, assess the problem and match the most appropriate and cost-effective controls to the situation. There are two basic control methods used in California: prevention and lethal control. It is almost impossible as well as cost prohibitive to exclude beavers from ponds, lakes, or impoundments.
Fencing off groups of trees or shrubs or garden plots with a low fence (3-feet-tall) will protect them. Since beavers generally do not like to stray far from water, fences may be effective even if they do not completely surround the area. The fence should be constructed of woven or welded wire and be well-anchored to the ground, so that beavers do not crush it, crawl under it, or walk over it. An electrified wire strung 4-6” above the ground may also be an effective beaver deterrent.
Protecting Trees and Plants
Valuable trees and other plants adjacent to waterways may be protected from beavers by encircling them with hardware cloth, welded wire mesh or sheet metal. Welded wire mesh of 2” x 4” is an optimal for effectiveness, durability, aesthetics and cost of construction.
Painting tree trunks with a sand and paint mixture may also prevent beaver gnawing, and may be more aesthetically pleasing than metal barriers. The sand/paint ratio should be approximately 8 ounces (2/3 cup) of fine sand to one quart of latex paint.
Beavers are attracted to the sound of running water and will repair most dam breaches and plug most culverts and pipes that are installed in order to drain the ponds. A variety of devices and designs have been developed for controlling beaver impoundments and keeping blocked culverts open. The Flexible Leveler and Beaver Deceiver are two examples. Visit www.beaversolutions.com for more information.
Modification of beaver dams, or any construction work within lakes or within the bed and bank of a stream, may require a Lake and Streambed Alteration Agreement from the California Department of Fish and Wildlife (CDFW). Contact your local CDFW office before attempting to install any beaver devices.
For questions and more information, contact your regional CDFW office.