A groundhog is a serious digger. One animal can move a surprising amount of dirt building a burrow, and when that burrow runs next to your foundation, it becomes a structural problem, not just a lawn problem. If you have a groundhog living near your house, the damage is often blamed on water or settling at first. The giveaway is the burrow entrance and the dirt piled next to it.
How a burrow damages a foundation
Groundhog burrows are not just a single hole. They run for dozens of feet, with chambers, a main entrance, and a couple of escape exits. When the tunnels run under or beside a footing, they pull soil out from where the foundation needs support. The ground settles unevenly, and you get cracks.
There is a second problem that people miss: water. A burrow can act like a drainage channel that points rainwater straight at your foundation instead of away from it. Water pools against the wall, builds up pressure, and finds its way into the basement or crawlspace. Over time that erodes more soil and makes the voids bigger.
Burrow dug under a shed footing
How to spot groundhog damage
- A mound of fresh dirt near the foundation, usually fan-shaped, where the animal pushed soil out of the entrance.
- A burrow entrance the size of a dinner plate or a bit larger, shaped like a half circle, within a few feet of the wall.
- Cracks in the foundation that appear or get worse, often following mortar joints in block walls.
- Water seeping into the basement or crawlspace after rain, new damp spots, or a musty smell.
A hard rule: do not fill in a burrow while the animal is still in it. Trap it first, then do the repair. Filling an active burrow just traps the groundhog, and it will dig a new exit, usually straight through whatever is in its way.
Repairing the damage
Get the groundhog out first, using a live trap baited with fresh vegetables or fruit. Check it regularly and follow your state’s rules for what to do with the animal. Then:
- Dig out the burrow so you can see the tunnels and remove the loose soil.
- Backfill in layers, compacting each layer before adding the next.
- If the burrow runs under the slab or footing, you may need a structural engineer, or a grout injection to fill the void under the concrete.
- Put down a barrier along the foundation so they do not dig back in. A trench lined with galvanized hardware cloth, bent outward at the bottom, works well.
For the foundation cracks themselves, a mason or foundation contractor will look at the same fixes they use for any settling: underpinning or piers, wall anchors, or epoxy injection. Groundhog damage often gets treated the same way as ordinary settlement once the animal is gone, but the void under the slab has to be filled or the problem comes back.
Preventing it from happening again
- Keep vegetation and brush cleared around the foundation. Groundhogs like cover.
- Remove food sources: fallen fruit, garden vegetables, bird seed.
- A gravel trench around the foundation is a solid barrier, groundhogs do not like digging through loose gravel, and it improves drainage at the same time.
- Walk the perimeter every month or two during the active season and look for fresh dirt.
Frequently Asked Questions
A full collapse is rare, but the uneven settling, cracks, and water damage are real and get worse the longer the burrow is active. Deal with it early and it rarely gets that far.
Usually a few feet deep, down below the frost line so the den stays a stable temperature. Near a foundation they will dig as deep as the soil lets them.
A burrow entrance near the foundation, fresh dirt at the base of the wall, new cracks, water in the basement, and the sound of digging or scratching under the floor.
Only after the animal is gone. Filling an active burrow traps it and makes it dig a new exit, often causing more damage. Trap and remove first, then fill.
