Gophers are subterranean pests whose extensive tunneling systems can create significant problems for homeowners, especially when their activity occurs near or directly beneath a structure. The constant excavation and soil displacement threaten the stability of concrete foundations and underground utility lines. Addressing a gopher infestation requires a targeted approach focused on safe removal and permanent structural exclusion.
Identifying the Threat to Your Foundation
Correctly identifying the pest as a gopher is the first step toward effective removal, as their tunneling habits differ from those of other burrowing animals. Gopher mounds are typically crescent or horseshoe-shaped, with a distinct soil plug visible on one side where the lateral tunnel was sealed. This differs from the volcano-shaped, symmetrical mounds created by moles, which have a plug in the center, or the un-mounded, open holes left by voles.
A gopher’s tunnel network is complex, often reaching depths of 6 to 18 inches, with some main runs extending several feet deep. When these tunnels are dug near a home, they remove supportive soil, creating voids underneath slabs, patios, and foundation footers. This lack of support can lead to uneven settling, manifesting as cracks in the foundation or concrete surfaces. Gophers have also been known to gnaw through utility cables, irrigation pipes, and drainage systems, resulting in costly leaks and service disruptions.
Safe and Effective Removal Techniques
Removing gophers from areas near a foundation requires methods that eliminate the pest without causing further soil instability or risk to non-target animals. Trapping is the most reliable and safest approach, offering clear confirmation of removal. Specialized scissor-style or wire traps, such as the Macabee, Victor Easy Set, or Cinch traps, are designed for use within the gopher’s main runway.
To place a trap effectively, you must first locate the main tunnel, typically found by probing 8 to 12 inches away from the plug side of a fresh mound. Once the main runway is intercepted, two traps are often set facing opposite directions to catch the gopher regardless of which way it approaches. Securing the traps with wire tethered to a stake prevents the gopher from pulling the device deep into the tunnel network.
Targeted baiting using products containing zinc phosphide is also an option, but it requires extreme caution due to its toxicity to non-target wildlife and pets. The bait must be placed deep into the active main burrow using a specialized probe or application device to minimize the risk of secondary poisoning. Applying the bait in this manner ensures the gopher consumes it underground and prevents surface broadcasting.
Methods that involve flooding or fumigation should be avoided near foundations, as they can lead to complications. Flooding tunnels near a structure can force water to seep into the foundation or crawl space, potentially causing structural damage or instability. Similarly, using fumigation techniques near a home can result in the gopher sealing off the tunnel, or cause a collapse of the tunnel system beneath the house.
Sealing Entry Points and Structural Remediation
Once the gopher has been successfully removed, the focus must shift to structural remediation to prevent re-infestation and stabilize the compromised soil. Simply covering the holes does not solve the problem, as gophers will often dig new exits or re-open the tunnel. The tunnels closest to the foundation must be thoroughly backfilled to restore soil density and prevent settling.
A mixture of gravel, dirt, and potentially a concrete slurry can be used to fill the voids, as the coarser material makes future tunneling more difficult. For tunnels directly under a concrete slab or patio, injecting a flowable concrete mix can help re-establish support. The goal is to eliminate air pockets and densify the soil, mitigating the risk of future ground collapse.
For long-term exclusion, a physical barrier is the most effective preventative measure. This involves installing galvanized hardware cloth with a small mesh size, such as half-inch openings, vertically along the foundation line. The barrier should extend at least 2 feet deep into the soil and be bent outward at the bottom to form an L-shape. This L-shape physically deters gophers from digging underneath the foundation footer.
Long-Term Landscape Deterrents
After removal and structural repairs are complete, implementing long-term landscape deterrents helps make the property less appealing to new gophers. Gophers are attracted to soft, moist soil that is easy to tunnel through and provides lush food sources. Reducing excessive irrigation, particularly where gopher activity is common, can help harden the soil and deter future digging.
Strategic planting can also serve as a secondary line of defense, as gophers tend to avoid certain plants. Integrating gopher-resistant varieties into the landscape can help make the area unpalatable. These plants possess strong scents or toxic bulbs that gophers find undesirable.
While often marketed as a solution, the effectiveness of sonic or vibrating spikes is limited and temporary. Gophers may initially be disturbed but often learn to navigate around the devices or simply tunnel deeper. Repellents based on castor oil may provide some localized, temporary deterrence near active holes but should be used as a supplement to, rather than a replacement for, physical barriers and trapping.