Landslides risk in California

You get the letter from your lender: the house on the ridge above town just got a new crack in the foundation. Now you're wondering if that could happen to you. In California, it can—and the risk isn't just in the famous canyons.

California is rated a level 4 out of 5 for landslide risk statewide. That's high. But the risk is not spread evenly. It depends on the slope, the soil, the rain, and what happened to the vegetation last fire season.

Why California looks like this

California's mountains are young and restless. The Coast Ranges, the Sierra Nevada, the Transverse Ranges from Santa Barbara to San Bernardino—they're all rising, faulting, and eroding at the same time. Add heavy winter rain, and you get landslides. The USGS Landslide Hazards Program maps show hot spots in Los Angeles, Orange, San Diego, Santa Barbara, Ventura, and the Bay Area counties like Alameda, Contra Costa, Marin, and Sonoma.

Pacifica has had entire apartment buildings red-tagged. Big Sur deals with Highway 1 closures. Laguna Beach and Malibu have their own histories. And it's not just the coast. The Sierra foothills, the wine country of Napa and Sonoma, and the hills above San Diego all have landslide-prone areas.

Wildfires make it worse. After a fire, the soil repels water, and a normal storm can turn into a debris flow. That's why the months after a major fire in the Santa Monica Mountains or the Sierra foothills are especially dangerous. The USGS and NOAA track this closely.

Insurance gaps people miss

Here's the hard part: your standard homeowners policy almost certainly does not cover landslide damage. Earth movement—landslides, mudslides, sinkholes—is excluded. Flood insurance through NFIP doesn't cover it either. Earthquake policies might cover landslide if the ground shaking caused it, but many don't, and you have to buy them separately. A few specialty insurers offer difference in conditions (DIC) policies, but they're expensive and rare. So if a hillside gives way, you might be paying out of pocket.

That's a gap most people don't discover until after the fact. If you're buying a house on a slope, ask the seller for any geotechnical reports. Talk to your insurance agent about what's actually covered—and get it in writing. The California Department of Insurance has resources, but the short version is: don't assume you're covered.

A practical weekend plan

You don't need to be a geologist. Start by walking your property. Look for new cracks in the foundation, driveway, or patio. Check for doors and windows that stick. Look at trees—if they're leaning or have soil pulling away from roots, that's a sign. Then check the USGS landslide maps for your area. If you're in a high-risk zone, hire a licensed geotechnical engineer for an evaluation.

Clear your gutters and drains. Don't overwater slopes. If you have a hillside, avoid planting heavy trees or shrubs that need a lot of water. And have an evacuation plan—know two ways out of your neighborhood.

If you only do one thing: after every big storm, take photos and videos of your property. That baseline helps if you ever need to file a claim or prove damage. It also helps you notice changes over time.

Questions we get

Does my California homeowners insurance cover landslide damage?

Almost never. Standard policies exclude earth movement. You'd need a separate policy, and even then, read the fine print. Some earthquake policies include landslide if the quake triggered it, but not all.

What's the difference between a landslide and a debris flow?

A landslide is a slow or fast movement of rock and soil. A debris flow is a fast, violent rush of mud, water, and debris, often after wildfire. Both can destroy a home, but debris flows give you less warning.

How do I know if my California house is in a landslide zone?

Check the USGS Landslide Hazards Program maps. Your county planning or public works department may have local maps. Cal OES has preparedness info. Also, look at the slope above and below your house—if it's steep and has springs or seeps, that's a red flag.

Official maps and agencies

• California Governor's Office of Emergency Services
• USGS Landslide Hazards Program
• Ready.gov – Landslides and Debris Flow