Fairfax County recently released educational material on its role and responsibilities in working with its furry, four-legged ecosystem engineers on private property following the board matter introduced by Supervisor Walter Alcorn (D-Hunter Mill) last June.
Human-beaver conflicts surfaced concerning vegetation and tree damage, safety concerns of tripping over stumps of felled trees, blocked road culverts, and flooding, which potentially undermines roadbeds, leading to maintenance and repairs. All these were caused by the instincts and actions of Castor canadensis, the American Beaver.
The large rodents are second only to humans in their ability to change the landscape. They typically weigh between 10 and 30 pounds (although they can weigh more) and have a stout body, small eyes and ears, a large, flat, hairless tail shaped like a paddle, an almost black waterproof fur coat, and webbed feet. They are herbivores, plant eaters with large orange incisors that grow continuously to counter wear and tear of chewing on trees. The beaver must keep the incisors worn back by using them daily. The tree damage appears as clean, axe-like cuts at a 45-degree angle. Beavers reside in semi-aquatic habitats and can stay underwater for up to 15 minutes at a time.
Fairfax County published best practices in its recently released beaver management information. The plan is to mitigate the situation amicably while respecting homeowners' rights and beavers’ needs while protecting land and infrastructure.
The guide covers, as directed, in Alcorn’s board matter, “updated educational outreach materials that outline applicable laws relating to beaver relocation or removal, provide guidance and resources for human/beaver coexistence, and describe the county’s role and responsibilities in the guidance as it relates to beavers and beaver activity on private property.”
Beavers, a keystone species, shape ecosystem and benefit wildlife. Dams store and release water to control downstream flooding. Beaver wetlands filter water, trap silt, and remove toxins. Slowing water flow stabilizes stream banks and promotes vegetation, reducing erosion. Beaver dams also recharge groundwater, ensuring water sustainability. Fish, amphibians, and birds use beaver ponds for habitat, and their ponds help with irrigation, flood control, and droughts.
Fairfax County recommends nonlethal ways to discourage beavers from maintaining dams on property, such as exclusion fencing and flow devices to manipulate the water level of a pond for a long-term, effective approach to reducing flooding and property damage associated with beaver damming activities. The county does not recommend lethal control of beavers.
Tree wrapping is one of two available tree protection measures recommended for high-value trees. Using galvanized welded wire fencing, 14-gauge with 2x4 mesh, encircle the trunk upwards four feet, leaving a 6-inch to 12-inch gap between the tree trunk and the fencing for future tree growth. Fasten the ends by bending or securing them with hog rings or zip ties. For clusters of shrubs or groves of trees, encircle the priority area with a single, larger-diameter fence instead of individual tree guards, as needed.
The second method of tree protection, which may deter beavers, is to paint the trunks of adult trees, not saplings, with a mixture of coarse mason's sand or playground sand (30–70 mil) and exterior latex paint. The ratio is twenty ounces of sand to one gallon of paint. Stir often, and paint tree trunks from the bottom of the tree to about 3–4 feet high.
As for flooding control, there are numerous designs for flow devices and fencing solutions, such as beaver baffles, beaver deceivers, Clemson beaver pond levelers, diversion dams, keystone fences, starter dams, and fence and pipe installations.
Beavers dislike the sound of running water; it signals a breach in their dam, prompting them to immediately begin its reconstruction, which can be completed within 24 to 48 hours. Hence, dam breaching and removal are ineffective. Additionally, "activities must comply with local, state, and federal laws and permitting related to land disturbance, floodplains, wetlands, or streams, including Resource Protection Areas and protected waters.
Beaver lodges or bank dens cannot be removed when occupied by beavers (Va. Code § 29.1-521). Virginia law prohibits the relocation of beavers. See also Va. Code 4VAC15-30-10.
Beaver trapping is a lethal control. "Beavers that are trapped must either be released onsite or humanely dispatched if the animal is removed from the property. The Fairfax County Animal Protection Police and Wildlife Management Office do not provide services for trapping and removal of nuisance beavers," states the county. Dispatched means killed.
You can find more information about permitting and Fairfax County's role and responsibility in beaver management at https://www.fairfaxcounty.gov/wildlife/beaver-management