Two of the perils most likely to destroy a California home — earthquake and flood — are the two that a standard homeowners policy flatly excludes. Owners routinely discover this only after a loss, when a claim for a shaken foundation or a flooded ground floor is denied. In a state defined by seismic risk, coastal and low-lying property, and post-wildfire debris flows, these are not exotic add-ons; they're the coverages that decide whether a catastrophe is an inconvenience or a financial ruin.

This guide explains why flood and earthquake are excluded, how each is actually insured in California, the percentage-deductible math that surprises people, the post-wildfire mudflow trap, and how higher-value homes secure adequate limits.

💡 The One-Line VersionStandard homeowners policies exclude both flood and earthquake. Earthquake is covered through the California Earthquake Authority (CEA) or private/DIC markets, with a percentage deductible (often 5–25% of the dwelling limit). Flood is covered through FEMA's NFIP (capped at $250,000 building / $100,000 contents for a home) or private flood for higher limits. High-value homes typically use private-client or DIC policies to get meaningful limits on both.

Why They're Excluded — and Why That Matters in California

Standard homeowners (HO-3/HO-5) policies exclude "earth movement" (earthquake, landslide) and "water damage" from flooding. Insurers exclude these because the losses are catastrophic and correlated — a single event hits thousands of homes at once — which is exactly why California, with its faults, coastline, rivers, and burn-scar hillsides, is where the exclusions bite hardest. Covering them requires separate, purpose-built policies.

Earthquake Insurance

The CEA and Private Markets

Most California earthquake coverage is written through the California Earthquake Authority (CEA), a publicly managed, privately funded provider whose policies are sold through participating residential insurers, alongside a growing private earthquake market and DIC options for higher-value homes. Coverage generally includes the dwelling, personal property, and loss of use (additional living expense), with options to tailor each.

The Percentage Deductible

Earthquake policies don't use a flat dollar deductible — they use a percentage of the dwelling limit, commonly ranging from about 5% to 25%. On a home insured for $1,000,000, a 15% deductible means you absorb the first $150,000 of loss. Lower deductibles cost more; the right choice balances premium against how much of a loss you could self-fund. This math is the single most important thing to understand before buying.

Earthquake coverage isn't about the cracked drywall — it's about the total loss. Because of the percentage deductible, it's most valuable precisely when a quake is catastrophic, which is exactly the scenario it's designed for.

Retrofitting

Seismic retrofitting — bolting the house to its foundation, bracing cripple walls — reduces damage and can earn premium discounts (the CEA offers a hazard-reduction/retrofit discount). For older California homes it's one of the best risk-reduction investments available.

Flood Insurance

NFIP vs. Private Flood

Flood is covered separately through:

  • The National Flood Insurance Program (NFIP), administered by FEMA — the baseline market, but with limits capped at $250,000 for the building and $100,000 for contents on a residential policy. There's typically a 30-day waiting period before coverage takes effect, so you can't buy it as a storm approaches.
  • Private flood insurance — increasingly available, often with higher limits, replacement cost on contents, and additional-living-expense coverage the NFIP doesn't provide. Essential for homes whose value exceeds NFIP caps.

You Don't Have to Be on the Coast

Flood risk isn't limited to mapped high-risk zones. A large share of flood claims come from moderate- and low-risk areas — flash flooding, overwhelmed storm drains, and rapid snowmelt. FEMA's flood maps determine mandatory-purchase requirements for federally backed mortgages, but they don't define where flooding can happen.

💡 Bollinsure TipAfter a wildfire, watch the mudflow trap. Burn scars dramatically raise the risk of debris flows, and coverage hinges on definitions: NFIP flood insurance covers "mudflow," but "landslide" and "mudslide" (earth movement) are excluded from both homeowners and flood policies. If you're below or near a recent burn area, review flood coverage before the first heavy rain — the 30-day NFIP waiting period means waiting is not an option.

High-Value Homes: Getting Adequate Limits

For an estate, NFIP's $250,000 cap and a basic earthquake policy may be far too little. High-value homeowners typically secure meaningful flood and earthquake limits through private-client carriers and Difference-in-Conditions (DIC) policies, which can bundle earthquake, flood, and other excluded perils at limits matched to the home's true rebuild cost. This is the same coordinated approach behind insuring the home itself; see our high-value home insurance guide and, for second homes, the vacation-home guide.

How to Cover These Gaps — A Practical Checklist

  • Confirm the exclusions — assume your homeowners policy covers neither flood nor earthquake unless proven otherwise.
  • Price earthquake with the deductible in mind — understand the percentage-deductible math against your ability to self-fund a partial loss.
  • Buy flood before you need it — mind the NFIP 30-day waiting period; consider private flood for higher limits.
  • Match limits to rebuild cost — use private/DIC coverage where NFIP or basic earthquake limits fall short.
  • Retrofit and mitigate — seismic retrofits and flood mitigation reduce loss and can lower premium.
  • Reassess after a wildfire — burn-scar mudflow risk changes your flood needs quickly.

Frequently Asked Questions

Does my homeowners insurance cover earthquakes or floods?

No. Standard California homeowners policies exclude both earthquake (earth movement) and flood. Each requires a separate policy — earthquake through the CEA or private/DIC markets, flood through the NFIP or private flood insurance.

Why is my earthquake deductible so high?

Earthquake policies use a deductible expressed as a percentage of your dwelling limit — often 5–25% — rather than a flat dollar amount. On a $1,000,000 dwelling limit, a 15% deductible is $150,000. That's why earthquake coverage is really designed for catastrophic loss; choose the deductible based on how much partial loss you could absorb yourself.

Do I need flood insurance if I'm not in a flood zone?

Often, yes. A large share of flood claims occur outside high-risk mapped zones, from flash flooding, storm-drain backups, and snowmelt. FEMA maps drive mandatory-purchase rules for mortgages but don't define where flooding can occur — and in California, post-wildfire debris flows add risk in areas that never flooded before.

Is post-wildfire mudflow covered?

It depends on the definition. NFIP flood insurance covers "mudflow," but "mudslide" and "landslide" (earth movement) are excluded from both homeowners and flood policies. If you're near a burn scar, review your flood coverage before the rainy season — and remember the NFIP's 30-day waiting period.

Sources & Further Reading

Talk to Bollinsure

Bollinsure is an independent California broker that closes the flood and earthquake gaps standard homeowners policies leave open — CEA and private earthquake coverage, NFIP and private flood, and DIC structures that give high-value homes adequate limits on both. If you own a California home and aren't certain you're covered for the ground moving or the water rising, a free review is the fastest way to find out. Request a review.