Landslides risk in Wisconsin

Landslide characteristics in Wisconsin

Wisconsin has a relatively low landslide risk compared to many other states. According to HomeRiskMap's hazard rating, the state is at level 1 out of 5 for landslides, meaning the overall threat is limited. However, this does not mean landslides never happen. Localized slope failures occur in certain parts of the state, particularly where steep bluffs, riverbanks, and unglaciated terrain exist.

The most vulnerable areas include the steep bluffs along Lake Michigan, especially in Milwaukee, Ozaukee, Racine, Kenosha, and Door counties. The Mississippi River valley in western Wisconsin also has steep slopes that can become unstable. In southwestern Wisconsin's Driftless Area—a region that was not flattened by glaciers—the landscape features deep valleys and steep hillsides that are more prone to landslides than the rest of the state. Landslides can also occur along other river bluffs and constructed slopes.

Landslides in Wisconsin are typically shallow, small-scale events rather than catastrophic ones. They are most common in spring during snowmelt and after periods of heavy rain, when water saturates the soil and increases its weight. Freeze-thaw cycles in late winter and early spring can also weaken slopes. Human activities such as construction on steep slopes, removal of vegetation, and poor drainage can increase the risk. The USGS Landslide Hazards Program provides national maps and research that show Wisconsin's overall susceptibility is low, but localized hotspots exist.

How it affects homes

When a landslide occurs near a home, the damage can range from minor to severe. Common impacts include cracks in foundations, walls, and driveways; shifting or settling of the structure; basement flooding from redirected groundwater; and damage to utilities, septic systems, and landscaping. In severe cases, a landslide can undermine a home's foundation, making it unsafe to occupy. Access roads and retaining walls may also be damaged or destroyed.

Standard homeowners insurance policies typically do not cover landslide damage. Most policies exclude "earth movement," which includes landslides, mudslides, and sinkholes. Flood insurance through the National Flood Insurance Program (NFIP) also does not cover landslide damage; it covers water damage from flooding, but not earth movement. Some specialized insurance products, such as a Difference in Conditions (DIC) policy, may offer coverage for landslides, but these are not common and must be purchased separately. Homeowners should review their policy and speak with an insurance agent to understand their options.

Because landslide risk in Wisconsin is generally low, many homeowners may never face this threat. However, those living on or near steep slopes, bluffs, or riverbanks should be aware of the potential for damage and take preventive measures.

How to prepare your home

If you live in an area with even a small landslide risk, there are steps you can take to protect your property and family. The following measures can help reduce the chance of a landslide affecting your home or reduce the damage if one occurs.

• Know your risk: Check local hazard mitigation plans and contact your city or county planning department to see if your area has a history of landslides. The Wisconsin Emergency Management website has preparedness information.
• Manage water drainage: Keep gutters and downspouts clean and direct water away from slopes and foundations. Avoid overwatering lawns on or near slopes. Consider installing French drains or other drainage systems designed by a professional.
• Maintain vegetation: Deep-rooted plants and trees help stabilize soil. Avoid removing vegetation from slopes, as this can increase erosion and instability.
• Avoid adding weight to slopes: Do not place fill, heavy structures, or large amounts of snow on the top of a slope. Consult a geotechnical engineer before building near a slope.
• Inspect your property regularly: Look for warning signs such as new cracks in the foundation, walls, or pavement; doors and windows that stick; tilting trees or utility poles; and new springs or seeps. These can indicate ground movement.
• Consult a professional: If you are concerned about slope stability, hire a geotechnical engineer or engineering geologist to assess your property and recommend solutions.
• Consider engineering solutions: Retaining walls, soil anchors, and drainage systems can stabilize slopes, but they must be designed by a licensed professional and may require permits.
• Have an evacuation plan: If you see signs of imminent landslide, evacuate immediately. Have a plan for where to go and how to contact family. Report changes to local authorities.
• Stay informed: Monitor weather forecasts and sign up for local emergency alerts. Heavy rain and rapid snowmelt are key triggers for landslides.

Frequently asked questions

Are landslides common in Wisconsin?

No, landslides are relatively rare in Wisconsin compared to states with mountainous terrain. However, localized landslides do occur, especially along steep bluffs like those along Lake Michigan and the Mississippi River. The USGS notes that while the overall risk is low, certain areas are more susceptible. Wisconsin Emergency Management encourages residents to be aware of local hazards.

Does homeowners insurance cover landslide damage?

Generally, no. Standard homeowners insurance policies exclude damage from earth movement, which includes landslides. Flood insurance also does not cover landslides. Some specialized policies may offer coverage, but you would need to purchase them separately. Review your policy and discuss options with your insurance agent.

What should I do if I notice signs of a landslide near my home?

If you see signs such as cracks in the ground, tilting trees, or shifting foundations, evacuate your home immediately if you feel it is unsafe. Contact your local emergency management office and report the conditions. Do not return until authorities have declared the area safe. For more information, see Ready.gov's landslide guidance.

Official resources

• Wisconsin Emergency Management – state agency responsible for emergency preparedness, response, and recovery.
• USGS Landslide Hazards Program – federal research and mapping of landslide risks across the United States.
• Ready.gov – Landslides and Debris Flow – national public preparedness campaign with tips for before, during, and after a landslide.