Flood plain zone how to#

Flood Zone AH Areas with a 1% annual chance of shallow flooding of, on average, 1 to 3 feet.

In old format FIRMs, the base floodplain is shown in numbered A zones numbered from A1 to A30.

Flood Zones AE / A1-30 Base flood elevations are provided within these areas.

Detailed analyses are not done on these areas and therefore no depths or base flood elevations are shown within “A” zones.

Flood Zone A These areas have a 1% annual chance of flooding, and therefore a 25% chance over the life of a 30-year mortgage.

The BFE is shown for zones: AE / A1-30, AH, AO, AR, and VE / V1-30.

In other terms, it helps to predict how high flood waters will rise in a particular location and elevation. It is the rise of surface water resulting from a flood that has a one percent chance of reaching or exceeding that level in any given year. The Base flood elevation (BFE) is an important metric for high risk and coastal flood zones. Homes and properties within these areas are subject to mandatory flood insurance purchase requirements. These features increase the likelihood of flood waters damaging the surrounding area. “A” areas are typically located near ponds, streams, and rivers. High risk flood areas have a 1 in 4 chance of flooding during a 30-year mortgage, otherwise known as a 1% annual flood risk. “X” zones are areas outside the 500-year flood and protected by levees from 100-year flood. “C” zones may have ponding or drainage issues. Flood Zones C and X (Unshaded) Areas with a minimal flood hazard above the 500-year flood level.“B” zones describe base flood plain areas with “lesser” hazards, such as areas protected by dams, dikes, levees, or shallow flooding areas with average depths of less than a foot etc. Flood Zones B and X (Shaded) Areas with a moderate flood hazard between the 100 and 500-year flood levels.Federal flood insurance is not required in these areas, but it is recommended for all property owners and managers. One in five insurance claims come from low and moderate risk areas these areas receive one-third of federal disaster assistance. These zones are not considered a part of the Special Flood Hazard Area, and are otherwise known as Non-Special Flood Hazard Areas (NSFHAs).Īlthough these areas typically have less than a one percent chance of flooding each year, it is still a good idea to be wary of flood dangers in these zones. In these areas, flood risk is present, but reduced from the intensity of high risk areas. Low and Moderate Risk Areas (FEMA Zones B, C, X) More explanation of much of this information on flood zone categories can be found on government flood resources. A 100-year flood area is one in which there is a 1% annual chance of flood and a 500-year flood corresponds to a 0.2 percent chance on average. To better understand what each flood zone means for a property’s likelihood of flood, FEMA maps often use the terminology of “100 and 500-year flood zones”.

“D” labels undetermined flood zones, where flood risk exists but is unmeasured. High risk areas are started by either “A” or “V”, low and moderate flood risk areas begin with “B”, “C”, or “X”. Special Flood Hazard Areas (SFHAs) are the areas that are at the greatest risk of flooding, mudflow, or flood-related erosion.

The type of flood zone that you are in affects the cost of flood insurance policies and flood insurance is mandatory in some flood zones. The maps are also unable to account for pluvial surface flooding caused by intense rainfall. Unfortunately, FEMA flood maps often struggle to fully account for changes in flood patterns due to climate change. Your flood zone can provide crucial information on the physical and financial risks to your property as a result of flood.

Flood plain zone how to#

For more information on reading a flood zone map, see our full FEMA flood maps guide which describes the terminology of flood maps, how to use them, and their connection to the National Flood Insurance Program (NFIP). You can locate your flood map using your street address through the FEMA Flood Map Service Center, or you can assess all your current as well as future climate risks with the ClimateCheck property report. Not all states require sellers to share flood risk information or reveal previous flooding or leakage to buyers. It is a good idea to research flood risk for your current or potential properties.