Landslides risk in Missouri

Landslide hazards in Missouri: what homeowners should know

Missouri’s overall landslide risk is rated 1 out of 5, meaning the hazard is relatively low compared to more mountainous states. However, “low” does not mean “none.” The USGS Landslide Hazards Program explains that landslides occur when soil, rock, or debris moves downslope, often triggered by heavy rain, rapid snowmelt, or changes to a slope. In Missouri, localized landslides happen most often in the Ozark Highlands, along the steep bluffs of the Mississippi and Missouri rivers, and in areas with thick deposits of windblown silt called loess, particularly in the southeast part of the state.

The most common triggers in Missouri are prolonged or intense rainfall, flash flooding, and freeze-thaw cycles that weaken soil and rock. Spring and summer thunderstorms can drop several inches of rain in a short time, saturating slopes and increasing pore water pressure. In late winter and early spring, snowmelt and repeated freezing and thawing can also destabilize bluffs and road cuts. The Missouri State Emergency Management Agency (SEMA) includes landslide hazards in statewide mitigation planning and works with local emergency managers to address risk.

Areas of greatest exposure include the steep, forested hollows of the Ozarks, the loess hills near the Mississippi River from Ste. Genevieve south toward the Bootheel, and river bluffs where streams and rivers undercut slopes. Landslides also occur along highway cuts, construction sites, and areas where drainage has been altered. Even a small slide can block a road or damage a single home, so property owners on or below steep slopes should pay attention.

How it affects homes

Landslides can damage homes in several ways. The most common damage comes from ground movement that cracks foundations, shifts walls, and breaks utility lines. Even slow, creeping movement can cause doors and windows to stick, drywall to crack, and chimneys to separate from the house. Faster debris flows or mudflows can push into homes, bury yards, and block driveways and roads. Water and debris can also enter basements and crawl spaces, leading to flooding and mold.

Other common impacts include:

• Foundation settlement or displacement, leading to costly structural repairs.
• Cracked or bowed basement walls, particularly on hillside homes.
• Broken water, sewer, or gas lines, which can create additional hazards.
• Failure of retaining walls, patios, decks, and driveways.
• Damage to septic systems and private wells.
• Debris blocking access for emergency vehicles and utility crews.

On the insurance side, it is important to know that 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 may cover mudflow when it is directly related to a flood, but it does not cover landslide. Some insurers offer difference-in-conditions (DIC) policies or endorsements that can add landslide coverage, but these are not common and may be expensive. Ready.gov advises homeowners to ask their insurance agent specifically about landslide and debris flow coverage. Document your home’s condition with photos and keep receipts for repairs or improvements.

How to prepare your home

If you live on or below a steep slope, in the Ozarks, or along a river bluff, there are practical steps you can take to reduce your risk. Landslides are often triggered or made worse by water, so managing drainage is one of the most effective things you can do.

• Get a professional slope evaluation. Hire a licensed geotechnical engineer or engineering geologist if your home sits on or below a steep slope. They can identify unstable areas and recommend fixes.
• Control water around your home. Keep gutters and downspouts clean, and extend discharge pipes well away from slopes. Repair leaking pipes, irrigation lines, and septic systems promptly. Avoid overwatering lawns and gardens.
• Maintain deep-rooted vegetation. Trees and shrubs with deep roots can help hold soil in place. Avoid removing vegetation from slopes, and do not add heavy fill or structures without engineering advice.
• Inspect for early warning signs. Look for new cracks in foundations, walls, or driveways; doors and windows that stick; tilting trees or utility poles; and bulging ground at the base of slopes. These can indicate ground movement.
• Avoid cutting into slopes. Do not excavate at the base of a slope or add fill at the top without a professional design. Retaining walls should be engineered and permitted.
• Plan your evacuation. Know how to receive local alerts, keep a go-bag ready, and practice a family evacuation plan. If you see signs of imminent movement, leave immediately and call 911.
• Review your insurance. Understand that standard policies exclude landslides. Ask your agent about flood insurance (for mudflow) and any available endorsements or specialized policies.
• Document your property. Take dated photos and keep records of maintenance and improvements. This will help if you need to file a claim.

For more preparedness guidance, contact your local emergency management office or visit the Missouri State Emergency Management Agency website.

Frequently asked questions

How common are landslides in Missouri?

Landslides are relatively uncommon statewide, and Missouri’s overall risk is rated low. However, localized landslides do occur, especially in the Ozark Highlands, along steep river bluffs, and in areas with loess or clay-rich soils after heavy rain. The USGS notes that landslides can happen anywhere slopes are steep and saturated, so even low-risk states can see isolated events.

Does homeowners insurance cover landslide damage in Missouri?

Usually not. Standard homeowners insurance policies typically exclude earth movement, which includes landslides and mudslides. Flood insurance may cover mudflow associated with flooding, but it does not cover landslide. Ready.gov recommends asking your insurance agent about specific coverage options and considering any available endorsements or difference-in-conditions policies.

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

First, ensure your safety. If you see new cracks in the ground or foundation, tilting trees or utility poles, or bulging ground at the base of a slope, evacuate immediately and call 911. Then contact your local emergency management office and a licensed geotechnical professional. SEMA and local officials can provide guidance on next steps and available assistance.

Official resources

• Missouri State Emergency Management Agency (SEMA)
• USGS Landslide Hazards Program
• Ready.gov – Landslides and Debris Flow