Look over your homeowner’s insurance policy, and you may be surprised to learn you’re covered for water damage, but not flooding. Flood’s cause water damage, but there’s a difference for insurers.

According to the National Association of REALTORS, approximately half of all flood disaster declarations since 1990 occurred in land-locked states, and flash floods have been reported in all fifty states. Yet only 12% of U.S. homeowners have flood insurance.

Homeowner’s insurance covers most losses due to storms, hail, pipe freezing, and the weight of snow or sleet but it may not cover water damage due to these events. It also may not cover flooding due to leaking appliances, stopped up sinks, broken toilets, etc. Your homeowner’s insurance policy should cover any sudden and unexpected water damage due to a plumbing malfunction or broken pipe. However, most home insurance policies exclude damage to your home that occurred gradually, such as a slow, constant leak. Also, some damage, such as mold, may be excluded from your standard policy depending on the cause.

So why isn’t water damage from catastrophic events like flooding covered? “Adverse Selection” is an industry term that simply means that the insurer can’t collect enough in premiums to cover the risk. Some insurers offer private flood insurance to high-end homeowners in limited groups, or they may offer limited coverage to policyholders that are part of the National Flood Insurance Program (NFIP), a federal program designed to help homeowners coverage for up to $250,000 for the structure of the home and up to $100,000 for personal possessions.

Most homeowners don’t need flood insurance, but to be certain, doublecheck with your insurer what water damage is covered by your policy and if you need additional insurance.