Flood Zones and Maps

Flooding is the most common of all natural disasters. The average home is more likely to be damaged by flooding than by fire, but flooding is not typically covered by homeowners insurance. Damages caused by flooding are second only to hurricanes as the most expensive of natural disasters, with almost $4 billion in claims annually. In addition, the average number of floods per year has increased six-fold from the 1960s to present day.

Is your home in a flood zone?  Scroll down to the bottom of this page to find out.

National Flood Insurance Program
Recognizing the devastating impact that flooding has on communities, Congress created the National Flood Insurance Program (NFIP) in 1968 to help provide a means for property owners to financially protect themselves. The NFIP offers flood insurance to homeowners, renters, and business owners if their community participates in the NFIP. Participating communities agree to adopt and enforce ordinances that meet or exceed FEMA requirements to reduce the risk of flooding. Participating communities also keep on file the flood maps and any amendments made to them and designate a staff person, typically the building official or engineer, to administer the program for the municipality.

Know Your Role, Know Your Risk And Take Action
Get helpful information from these FEMA brochures. Get a list of floodplain managers for Westchester County or contact Mark Lewis, NYSDEC Regional Floodplain Management Coordinator at . or (845)-256-3822. More information on the NFIP can be found at www.floodsmart.gov.

Flood Insurance Rate Maps (FIRMs)
Every property is subject to flooding at one time or another. Every storm is different. Specific conditions of storms, watershed conditions, storm sewer infrastructure, the site and surroundings as well as the buildings themselves will all influence the degree to which property may be damaged during an actual storm event. For these reasons, it is important to note that flood maps do not map the boundaries of where flooding will and will not occur. A Flood Insurance Rate Map (FIRM) depicts the statistical likelihood of flooding for typical types of storms modeled by FEMA. The maps show the susceptibility of properties to flooding, not the absolute boundaries of flooding. FIRMs are used by the insurance industry to calculate rates based on the level of risk dictated by the flood zone that the property being insured is located in.

FIRM Updates
The Federal Emergency Management Agency updates the Flood Insurance Rate Maps at regular intervals. The most recent update for Westchester County occurred in 2007. That update, however, did not include the more detailed coastal analysis that was just underway at that time. That coastal analysis was completed and incorporated into updated FIRMs in 2014, resulting in new coastal boundary and base flood information as well as the creation of an additional flood zone, the Limit of Moderate Wave Action (LiMWA) described below. The updated maps may be revised by FEMA in response to comments and appeals made during the public review and comment period which ended in July, after which FEMA will issue final maps. Each effected municipality must adopt the new maps within six months of issuance of the final maps by FEMA in order to remain in the National Flood Insurance Program.

Go to list and map of coastal Westchester FIRM panels.

The revised panels were released on December 9, 2014 and copies were sent to the effected municipalities. A public open house to review the updated map panels and discuss the implications for land use and flood insurance was held on Wednesday, March 11, 2015 at the County Center in White Plains. The Department of Planning prepared maps and a list of potentially impacted properties by municipality. FEMA also has an informational brochure. The public comment period was closed in July of 2015, and the revised maps are currently undergoing revisions in response to an appeal filed by the City of New York. These revisions will take at least one year to complete and will incorporate data from more recent storms such as hurricanes Irene and Lee and Superstorm Sandy. Once completed, each effected municipality must adopt the updated FIRMs within six months of issuance by FEMA in order to remain in the National Flood Insurance Program. In the interim, FEMA is recommending that municipalities use the data from the preliminary maps to provide the most conservative estimates to reduce flood risk associated with new development and redevelopment. For more information on the timeline and status of the updated maps, check this Web page or contact David Kvinge, Director of Environmental Planning, at the Westchester County Department of Planning at  or (914) 995-2089.

Non-Regulatory Data
Information about flooding and the National Flood Insurance Program can be found at the Web site floodsmart.gov. FEMA has also produced a number of non-regulatory products through its RiskMAP program, available for viewing or download at the FEMA Region 2 Web site. (URL link www.region2coastal.com/community-officials/flood-risk-tools).

Flood Zones
Flood Insurance Rate Maps (FIRMs) use an aerial image as a background and labels streets, water features and other major features. Most importantly, the FIRMs show the boundaries of a variety of flood zones, called Special Flood Hazard Areas. Please note that a surveyor or engineer experienced with FIRMs should be consulted to determine more precise boundary and elevation data from detailed information provided in the Flood Insurance Studies, which accompany the FIRMs.

Moderate to Low Risk Areas

In moderate-to-low risk areas, the risk of being flooded is reduced but not completely removed. These areas submit over 20% of NFIP claims and receive one-third of disaster assistance for flooding. Flood insurance isn't federally required in moderate-to-low risk areas, but it is recommended for all property owners and renters. These are shown on flood maps as zones labeled with the letters B, C or X (or a shaded X).

High Risk Areas

In high-risk areas, there is at least a 1 in 4 chance of flooding during a 30-year mortgage. All home and business owners in these areas with mortgages from federally regulated or insured lenders are required to buy flood insurance. They are shown on the flood maps as zones labeled with the letters A or V. Special Flood Hazard Areas (SFHA) are described in more detail below.

A - Areas subject to inundation by the 1-percent-annual-chance flood event generally determined using approximate methodologies. Because detailed hydraulic analyses have not been performed, no Base Flood Elevations (BFEs) or flood depths are shown.

AE and A1-30 - Areas subject to inundation by the 1-percent-annual-chance flood event determined by detailed methods. Base Flood Elevations (BFEs) are shown.

AH - Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually areas of ponding) where average depths are between one and three feet. Base Flood Elevations (BFEs) derived from detailed hydraulic analyses are shown in this zone.

AO - Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually sheet flow on sloping terrain) where average depths are between one and three feet. Average flood depths derived from detailed hydraulic analyses are shown in this zone.

AR - Areas that result from the decertification of a previously accredited flood protection system that is determined to be in the process of being restored to provide base flood protection.

A99 - Areas subject to inundation by the 1-percent-annual-chance flood event, but which will ultimately be protected upon completion of an under-construction Federal flood protection system. These are areas of special flood hazard where enough progress has been made on the construction of a protection system, such as dikes, dams, and levees, to consider it complete for insurance rating purposes. Zone A99 may only be used when the flood protection system has reached specified statutory progress toward completion. No Base Flood Elevations (BFEs) or depths are shown.

V - Areas along coasts subject to inundation by the 1-percent-annual-chance flood event with additional hazards associated with storm-induced waves. Because detailed hydraulic analyses have not been performed, no Base Flood Elevations (BFEs) or flood depths are shown.

VE and V1-30 - Areas subject to inundation by the 1-percent-annual-chance flood event with additional hazards due to storm-induced velocity wave action. Base Flood Elevations (BFEs) derived from detailed hydraulic analyses are shown.

LiMWA - An additional area that may be shown on coastal FIRMs for informational purposes is the Limit of Moderate Wave Action (LiMWA). The LiMWA identifies areas that will be affected by waves with a 1.5 foot wave height or greater within the coastal A zone. While FEMA currently does not require special floodplain management standards or flood insurance purchase requirements based on LiMWA delineations, it is likely that properties and structures within the LiMWA will receive substantial damage from wave action during a one-percent-annual-chance flood event. As a result, communities are encouraged to adopt the more stringent building construction standards applicable for V Zones in these areas. Go to fact sheet on LiMWA.

Flood Insurance and Grandfathering
Flood insurance rate maps (FIRMs) are used by the insurance industry to determine risk and insurance premiums. When FIRMs are updated, zone boundaries and base flood elevations may change, impacting the insurance requirements and costs for properties. To minimize this impact, the federal government has developed a grandfathering procedure, described in detail in this pamphlet. To see if your property is impacted by the proposed maps, make a map using the FEMA map tools below for both the effective (current) maps and the preliminary (proposed) maps. You can use this worksheet to document the information for your property.

Am I in a Flood Zone?
Use the following resources to find out if your property is in a flood zone.

1. Use the “What is my BFE” tool from FEMA. BFE stands for Base Flood Elevation.

2. Download the FIRM for your property.

3. Create a flood maps for your property using FEMA’s FIRMette tool.

  • Visit the FEMA FIRMette Web site.
    Enter the address you are looking for. A new page will open with a map. From here you can create a FIRMette by clicking the “View” button. A new window with the FIRM will appear. Then click on the “Make a FIRMette” button.

4. Find your property on the county’s interactive maps.

  • Go to Mapping Westchester County.
  • Enter your address and click "Go."
  • Select the "Show Additional Data on Map" tab at lower right, click the "plus" sign in front of “Environmental Features” and then check the check box in front of "Floodplains."
  • Zoom in on your property and use the information tool (the circle with the lower case “i” in it) to click on your parcel.
  • A dialogue box will open with the property information on it. Use the arrows at the top of the small dialogue box to scroll through the different datasets until you get to the flood information.