Major weather events such as Hurricanes Katrina and Sandy have demonstrated the devastation that sudden flooding can cause. While major storms like these thankfully don’t happen on a regular basis, even a small amount of flooding can be a major concern for a home owner. It doesn’t necessarily take a big storm to cause trouble: Heavy rains or melting snow can lead to flooding if drainage is insufficient. Anywhere there’s rain, there can be flooding. But how do you know if you need flood insurance?

Fixing flood damage can cost thousands of dollars. Standard home owner’s insurance doesn’t typically cover flooding. The National Flood Insurance Program (NFIP) offers flood insurance to home owners and renters. People who live in high-risk areas are legally obligated to take out flood insurance if they have a federally backed mortgage. If you live in an area that benefits from a program like NFIP, you will need to take out flood insurance to get a mortgage. Even if you do not live in one of the NFIP communities, your mortgage provider may insist that you take out flood insurance. If none of these provisions applies to you, insurance is your choice, but it’s probably a very good decision. You can find out more about the practicalities of buying flood insurance from the Federal Emergency Management Agency (FEMA).

You may be required to take out flood insurance if your mortgage lender specifies this in your policy. Make sure to check out any small print in your mortgage contract. Mortgage lenders often have the right to change the requirement for flood insurance even after your mortgage payments begin. If this happens, your mortgage lender should contact you to let you know that you should buy flood insurance. There are also designated flood-hazard areas defined and categorized by FEMA; these are at higher risk for flooding. It may be hard to buy a home in these areas without adequate flood insurance.

Flood risk often changes over time. FEMA updates flood hazards across the country. Flood maps, also known as Digital Flood Insurance Rate Maps, show flood risk at a property-by-property level. When new maps are issued, your risk may change, as well as whether you will require flood insurance. If your property is mapped out of a high-risk area, your insurance rates can go down. However, if you are mapped into a high-risk area, you will probably be required to purchase flood insurance, if your mortgage is held through a federally regulated or insured lender. You can check out the update schedule on the FloodSmart website

FEMA advises that even houses in low flood-risk areas should have flood coverage. According to FEMA records, since 1978 over a quarter of all flood claims have come from home owners in areas with low or moderate flood risks. According to statistics gathered by the NFIP, within a 30-year mortgage, a home owner has a 9 percent chance of making a claim for fire damage, compared with a 26 percent chance of making a flood-damage claim.