How deep are groundhog burrows and what damage can they cause?
Direct answer
Groundhog burrows can run several feet deep and extend many feet long with chambers and multiple entrances. The biggest practical problem is not the exact depth. It is the underground voids and soil movement they create. If a burrow is near or under a deck, shed, steps, slab, or foundation, treat it as higher risk and focus on safe removal/exclusion first, then proper backfill and compaction.
Quick decision table
| Your situation | Best next move | Why |
|---|---|---|
| Burrow in open yard, away from structures | Confirm activity > removal/exclusion > fill and compact | Lower structural risk; easier to verify inactivity |
| Burrow under deck/shed/steps/patio slab | Pro wildlife control + exclusion mesh, then repairs | Harder to confirm exits; voids can worsen settlement |
| You see sagging soil, sink spots, or shifting pavers nearby | Address burrow first, then backfill/compact in lifts | Filling without exclusion often leads to re-digging |
| Multiple entrances / you cannot find the main hole | Track entrances + consider professional help | Missed openings make DIY sealing fail |
What a groundhog burrow is like
- Multiple openings: often a main entrance plus one or more escape exits.
- Long tunnels: runs can extend well beyond what you can see from the hole.
- Chambers: nesting/rest areas and separate side areas can exist inside the system.
- Site choice matters: edges of lawns, brush lines, and sheltered spaces under structures are common.
Damage groundhogs can cause
- Settlement and sink spots: voids collapse over time, especially after rain.
- Undermining slabs and steps: pavers, patios, and walkways can shift as soil moves.
- Deck and shed issues: burrows near footings or pads can reduce support and create unevenness.
- Trip hazards: sudden soft spots and holes in lawns.
- Garden damage: feeding on plants plus soil disturbance around beds.
What to do (safe order)
- Confirm activity: smooth the dirt at the entrance and check for fresh digging within 24 to 48 hours.
- Locate other entrances: walk the perimeter (fence lines, brush edges, under-deck openings).
- Do not seal an active burrow: avoid trapping an animal inside or creating odor problems.
- Remove or exclude: once the animal is out (or removed), block re-entry with heavy-gauge mesh.
- Backfill in lifts and compact: add soil in layers, compact each layer to reduce future settling.
- Prevent the dig-under comeback: bury hardware cloth or use an outward L-footer at edges.
How to backfill correctly (so it does not sink again)
- Do it after exclusion: otherwise they often reopen the same spot.
- Use layers: backfill in several lifts, not one giant dump of loose soil.
- Compact each lift: tamp firmly to reduce voids and settling.
- Expect some settling: plan to top off and reseed after the first rain cycle.
- Watch drainage: divert downspouts and surface water away from the repaired area.
Common mistakes
- Sealing or filling a burrow while it is active.
- Assuming there is only one entrance (missed exits = repeat problems).
- Repairing a patio/steps before the burrow is addressed (damage returns).
- Backfilling without compaction (creates future sinkholes).
- Relying on repellents alone after a burrow is established.
FAQ
How deep are groundhog burrows?
Depth varies by soil and site, but groundhog burrows commonly run several feet below the surface with tunnels and chambers. The bigger practical issue is the extent of the system and the voids it creates, especially near structures.
Can a groundhog burrow cause a deck or shed to sink?
Yes. Burrows can create voids that lead to soil settling and loss of support near pads, steps, slabs, and footings. If the burrow is under a structure, prioritize safe removal/exclusion and consider professional help.
Is it safe to fill a groundhog hole right away?
Do not fill or seal an active burrow. Confirm the animal is out (or removed), install exclusion to prevent re-entry, then backfill and compact properly. Sealing too early can trap an animal and create odor issues.
How do I tell if the burrow is active?
Fresh digging, a clear open entrance, worn paths, and new disturbance after you smooth the dirt at the entrance (checked within 24 to 48 hours) are common signs of activity.
Related pages
- How deep are groundhog burrows and what damage can they cause?Learn typical groundhog burrow depth and tunnel layout, the kinds of damage they cause near decks/sheds/foundations, and the safest order to fix the problem.
- Groundhog burrow entrances: how many there are and how to find themGroundhog burrows often have multiple hidden entrances. Learn how many holes to expect, where escape exits are usually located, and how to find them before sealing.
- Do mothballs, ammonia, or ultrasonic repellents work for groundhogs?Do mothballs, ammonia, and ultrasonic devices actually work for groundhogs? Learn why these repellents usually fail, what can be risky, and what works instead (exclusion + proper backfill).
- How to deter groundhogs and get rid of them safelyA practical, step-by-step guide to deterring groundhogs, preventing burrows, and knowing when removal or a pro is the best option.
- How to Find and Safely Fill Groundhog BurrowsLearn how to locate all groundhog burrow entrances, confirm activity, and fill tunnels correctly to prevent collapse, odors, and repeat digging.
Sources and assumptions
- General wildlife control best practices: confirm activity, remove/exclude first, then seal and compact.
- Burrow depth varies widely; this page focuses on practical risks (voids, settlement) and safe remediation order.
- This page is informational and not a substitute for local legal guidance on wildlife handling or structural advice.