- Consult an architect, engineer and/or building construction professional. Professionals can guide you through the complexities of home elevation.
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1.1 WHAT ARE ADVISORY BASE FLOOD ELEVATIONS (ABFEs)?
ABFEs are advisory in nature and more accurately reflect the true 1% annual chance flood hazard elevations in a given area. Following large storm events, such as Hurricane Sandy, FEMA performs an assessment to determine whether the 1% annual chance flood event, shown on the effective FIRMs adequately reflects the current flood hazard. In some cases, due to the age of the analysis and the science used to develop the effective FIRMs, FEMA determines there is a need to produce ABFEs. ABFEs are provided to communities as a tool to support them in recovering in ways that will make them more resilient to future storms.
1.2 HAS FEMA ISSUED ABFEs IN THE PAST? IF SO, WHERE, AND WAS IT SUCCESSFUL?
Yes, FEMA developed ABFEs after Hurricane Katrina in 2005. Many communities adopted ABFEs in Louisiana and Mississippi, which resulted in home and business owners building higher and safer. This also meant lower flood insurance premiums once the flood elevations were adopted based on the revised FIRMs several years later.
1.3 FOR WHAT COUNTIES IN NEW JERSEY AND NEW YORK ARE ABFEs AVAILABLE?
ABFEs are available for Union County, NJ. ABFE information has also been released for Rockland and Westchester Counties, New York.
ABFE information is available through the View FEMA Flood Hazard Data page. Learn about preliminary work maps and preliminary FIRMs which are now the most recent data available from FEMA in certain areas, on this page as well.
1.4 HOW WILL ABFEs BE DEVELOPED FOR THE COUNTIES IMPACTED BY HURRICANE SANDY ?
FEMA will use updated coastal study methodologies and topographic data in coastal New Jersey and New York. These ABFEs will also build on the work already underway and reflect an updated coastal analysis.
1.5 WHAT INFORMATION WILL ABFEs INCLUDE THAT WILL BE AVAILABLE TO STAKEHOLDERS?
ABFEs will include advisory coastal flood hazard elevations and associated advisory maps. This information includes the following:
- Advisory Data Layers by County: Geospatial layers depicting ABFEs and updated flood zones (including but not limited to Advisory Flood Hazard Zone A, Advisory Flood Hazard Zone V, Limit of Moderate Wave Action (LiMWA), and Area of Moderate Wave Action, also known as Coastal A Zone), high water marks reflecting Hurricane Sandy’s impact, and U.S. Fish and Wildlife Coastal Barriers Zones that communities can input into existing Geographic Information Systems (GIS) to help make decisions about zoning, building, and redevelopment.
- Advisory Maps by County: Paneled maps depicting the geospatial data layers referenced above. These advisory maps will reflect higher flood elevations and, in some cases, more expansive coastal flood zones.
- Methodology Report for ABFEs: A report summarizing the methodologies, assumptions, and data sources used in developing the advisory data layers and maps.
1.6 WHAT IS THE LIMWA AND HOW WAS IT ESTABLISHED?
Flood hazard identification under the NFIP divides the coastal flood hazard area into two flood zones: Zone VE and Zone AE. Present NFIP regulations make no distinctions between the design and construction requirement for coastal AE and Riverine AE Zones. However, evidence suggests that design and construction requirements in some portions of coastal AE Zones should be more like VE Zone requirements. Post-storm investigations have shown that typical AE Zone construction techniques (e.g., wood-frame, light gauge steel, or masonry walls on shallow footings or slabs, etc.) are subject to damage when exposed to waves less than 3-feet in height. Laboratory tests and field investigations confirm that wave heights as small as 1.5 feet can cause failure of the above-listed walls types. One of the hazard identification criteria for VE Zone designation is where wave heights are estimated to be equal to or greater than 3 feet.
For advisory purposes, FEMA has divided Zone AE in coastal New Jersey and New York counties on the Advisory Maps by the LiMWA. The LiMWA represents the landward limit of the 1.5-foot wave. The area between the LiMWA and the Zone V limit is known as the Coastal A Zone for purposes of the building code and floodplain management standards and as the Moderate Wave Action (MoWA) area by FEMA flood maps. This area is subject to wave heights between 1.5 and 3 feet during the base flood. The area between the LiMWA and the landward limit of Zone A due to coastal flooding is known as the Minimal Wave Action (MiWA) area, and is subject to wave heights less than 1.5 feet during the base flood. Information about adopting and using the LiMWA by communities where these areas have been designated is provided in Section 2.
Since 2009, FEMA has included the LiMWA on preliminary digital FIRMs for coastal communities. However, if a community does not want to delineate the LiMWA on its final digital FIRM, it can provide a written request to FEMA, with justification, to remove it.
1.7 WHEN WILL ABFEs BE AVAILABLE?
ABFEs are available for all or portions of Union County, New Jersey; and Rockland and Westchester Counties, New York.
1.8 WHO SHOULD USE ABFEs?
Communities must use ABFEs for any FEMA Recovery or Mitigation activity (e.g. Public Assistance, Hazard Mitigation Grants). In addition, FEMA recommends that community officials including building and floodplain management officials, property owners, business owners, architects, builders, and engineers use this information because ABFEs will more accurately depict the current flood hazards.
1.9 HOW CAN ABFEs BE ACCESSED?
ABFEs will be available on this website. Guidance to enable users to make informed decisions regarding rebuilding communities is also included on this page.
1.10 HOW WILL THE IMPACTS OF HURRICANE SANDY BE FACTORED INTO THE ADVISORY INFORMATION?
The specific magnitude and track of Hurricane Sandy will not be factored into the updated coastal analysis for ABFEs. FEMA uses statistical probabilities of historic storms as part of the updated coastal analysis, which does not include any individual event from past history. Historical storms of similar paths and magnitudes to Hurricane Sandy are accounted for within the statistical analysis, and the inclusion of Hurricane Sandy would not affect the outcomes of ABFEs or the depiction of the advisory flood zones. FEMA will provide specific high water marks observed from Hurricane Sandy and collected by the United States Geological Survey as point data on the advisory maps. Also, a range of surge elevations that occurred as a result of Hurricane Sandy will be provided in the informational section of each advisory map panel.
1.11 WHY ARE SOME ABFEs HIGHER THAN THE ELEVATIONS SHOWN ON THE EFFECTIVE FIRMS?
Flood risk can change over time due to changes in climate, population, development in and around the community, and other factors. The Base Flood Elevations (BFEs) shown on the current, effective FIRMs are based on studies that were performed more than 25 years ago. ABFEs are based on information from the flood risk mapping studies that were already underway before Hurricane Sandy, and include an additional 25 years of flood data and updated topographic data. As a result, ABFEs will reflect higher elevations than the BFEs shown on current, effective FIRMs.
1.12 WHY DO ABFEs SHOW SOME ELEVATIONS LOWER THAN HURRICANE SANDY FLOOD ELEVATIONS?
ABFEs are based on the 1% annual chance flood event. ABFEs may show elevations lower than Hurricane Sandy in certain areas because Sandy was a more extreme event than the 1% annual chance flood in those areas. The elevations of the 1% annual chance flood are the NFIP standard for floodplain management. It is important to note that buildings constructed to this standard are still vulnerable to the effects of larger events like Hurricane Sandy.
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Floodplain Management Questions on the Use of ABFEs and Advisory Maps for Reconstruction
2.1 IS MY COMMUNITY REQUIRED TO ADOPT THE ADVISORY MAPS AND ABFEs FOR RECONSTRUCTION TO REMAIN ELIGIBLE TO PARTICIPATE IN THE NFIP?
No. The National Flood Insurance Program (NFIP) floodplain management regulations do not require communities to use flood hazard data from the ABFE maps in lieu of using flood hazard data from an existing effective FIRM and FIS report.
While the use of flood hazard information in draft or preliminary form may not be an NFIP requirement, the State of New Jersey is using this information as the basis for statewide floodplain development standards. New York City has adopted similar requirements. Learn more about these requirements through the State of New Jersey Department of Environment Protection’s Frequently Asked Land Use Permitting Questions page
and through New York City’s Press Release
regarding Sandy Legislation (Intro 983-A, Int. 990-A, Intro 1085-A, Intro 1089-A, Intro 1096-A, 1099-A).
2.2 WHAT ARE THE BENEFITS TO MY COMMUNITY OF USING OR ADOPTING ABFEs AND ADVISORY MAPS?
Although FEMA cannot require communities to adopt the ABFEs and Advisory Maps, using ABFEs and the other advisory information on the maps for rebuilding can reduce the vulnerability of structures to flooding and flood damages. Constructing buildings to ABFEs may decrease the cost of flood insurance, as well as the cost to recover from future storm and flood events. While the initial cost to rebuild to ABFEs may be slightly higher, communities and property and business owners will save money over the long-term by having structures that are built high enough and have the structural integrity to resist flood forces that may be encountered in future events. FEMA will provide technical assistance to communities in adopting and implementing ABFEs and advisory maps.
2.3 IF MY COMMUNITY DECIDES TO ENFORCE ABFEs, WILL IT NEED TO AMEND ITS FLOODPLAIN MANAGEMENT REGULATIONS AND/OR THE INTERNATIONAL BUILDING CODES® TO REFLECT ABFEs?
Generally, yes. Your floodplain administrator will need the authority to require use of the ABFEs and Advisory Maps. If your community chooses to use this information, FEMA advises that the community formally adopt the ABFEs and Advisory Maps so that it becomes legally enforceable.
When communities receive ABFEs and Advisory Maps or have evidence that there is an increased flood hazard risk, communities have a responsibility to evaluate and prudently use this information for actions in the floodplain to make structures less vulnerable to flood damage and help secure the health and safety of citizens. Building codes and floodplain management regulations generally require all new construction to meet the BFE and/or the design flood elevation, which would include ABFEs and Advisory Maps once adopted.
2.4 WHAT LANGUAGE SHOULD MY COMMUNITY USE TO ADOPT THE ABFES?
If the Advisory Map for your community includes a Limit of Moderate Wave Action (LiMWA), your community’s legal counsel (or other similarly qualified official) should determine if it is necessary to adopt this provision separately into the ordinance. There presently are no NFIP floodplain management requirements or special insurance ratings associated with the designation of the LiMWA. However, in areas designated with a LiMWA, there are requirements imposed by the I-Codes. Aside from the I-Code requirements, communities are encouraged to adopt Zone V requirements rather than the minimum NFIP requirements in these areas to address the increased risks associated with waves and velocity action. Additionally, be sure to contact your state regulating agency for information on more stringent state requirements which may apply.
The Community Rating System (CRS) awards credit points to communities that extend Zone V design and construction requirements to the LiMWA, and additional points to communities that extend Zone V requirements landward of the LiMWA.
2.5 IF THE COMMUNITY ADOPTS THE ADVISORY DATA, DO THEY APPLY TO NEW CONSTRUCTION, SUBSTANTIAL IMPROVEMENTS, AND SUBSTANTIAL DAMAGE?
Generally, yes. Since FEMA cannot mandate that communities adopt and enforce the advisory data (for non-FEMA Recovery or Mitigation activities); FEMA recommends that communities apply the adopted ABFEs to new construction, substantial improvements, and substantially damaged structures to ensure that all recovery construction is built stronger, safer, and less vulnerable to future flooding events.
2.6 IN AREAS WHERE THE IMPACTS OF HURRICANE SANDY ELEVATIONS EXCEED ABFEs, SHOULD COMMUNITIES BUILD HIGHER?
Yes. It is good practice to build higher. Some options that communities and property owners have to provide additional protection include:
• Adopt or use freeboard on top of ABFEs.
• The use of pile or column foundations to elevate residential buildings is required in V zones. In addition, this may be required in existing AE zones.
2.7 CAN MY COMMUNITY ADOPT A FREEBOARD REQUIREMENT ON TOP OF ITS CURRENT BASE FLOOD ELEVATIONS (BFEs) AS AN ALTERNATIVE TO ADOPTING ABFEs?
Yes. However, communities should use caution in adopting BFEs plus freeboard if they are lower than ABFEs. Structures constructed to the BFE plus freeboard will be more susceptible to flood damage than structures built to the ABFE, if the ABFE is higher.
In addition, property owners and communities need to be aware that insurance rates will also be affected by the Biggert-Waters Flood Insurance Reform Act of 2012, which mandates eliminating flood insurance premium subsidies and discounts and increasing rates to reflect the actual risk. If the new effective FIRM has BFEs that are higher, residents whose buildings are below the new level could pay substantially higher premiums for flood insurance.
2.8 WHEN FEMA PROVIDES FINAL FIRMS THAT REPLACE ABFEs, WILL MY COMMUNITY BE REQUIRED TO ADOPT THE REVISED FIS REPORT AND FIRMs?
Yes. Any time that FEMA revises the effective FIRMs, the community must adopt or amend their floodplain management regulations to incorporate the new data and meet any additional floodplain management requirements. Additional information about adopting FIRMs can be found in FEMA’s brochure, Adoption of Flood Insurance Rate Maps by Participating Communities (FEMA 495).
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Flood Insurance Implications
3.1 IF COMMUNITIES ADOPT AND UTILIZE ABFEs, HOW WILL THAT AFFECT OWNERS’ FLOOD INSURANCE PREMIUMS AND POLICIES?
Adopting standards based on ABFEs will not change the zones or elevations currently in effect, and premiums will continue to be rated based on the map currently in effect and the lowest floor of the building. Flood insurance policies are rated using the zones and flood elevations on the current effective FIRM. Flood insurance premium rates may be affected by the Biggert-Waters Flood Insurance Reform Act of 2012 (see Question 3.3).
3.2 HOW CAN PROPERTY OWNERS AND RENTERS REDUCE THEIR FLOOD INSURANCE PREMIUMS?
A primary way to reduce or avoid future flood losses is to raise your building above the BFE. You could reduce your flood insurance premium by 85 percent or more — and save thousands of dollars over the life of your home or business. It is important to understand the long-term costs and benefits when considering your options for repairing, rebuilding, or relocating.
3.3 WHAT WILL HAPPEN TO RENEWAL RATES FOR EXISTING FLOOD INSURANCE POLICIES IF THE FIRMS ARE REVISED IN THE FUTURE TO REFLECT NEW, HIGHER ELEVATIONS?
As flood maps are updated, flood zones and associated premiums could change to reflect the new flood risk. Rates will also be affected by the Biggert-Waters Flood Insurance Reform Act of 2012, which mandates eliminating flood insurance premium subsidies and discounts and increasing rates to reflect the actual risk. If the new effective FIRM has BFEs that are higher, residents whose buildings are below the new level could be required to pay substantially higher premiums for flood insurance.
If property owners simply rebuild to pre-flood conditions, flood insurance premiums could increase dramatically in the near future. If the property owner has a “grandfathered” policy and the area is remapped, they could see an increase of over 200% over five years!
3.4. WILL INCREASED COST OF COMPLIANCE (ICC) BENEFITS BE AVAILABLE TO HELP COVER THE COSTS TO ELEVATE THE BUILDING?
ICC coverage is a standard coverage in most NFIP policies. The coverage provides up to $30,000 to help property owners reduce the risk of damage from future floods by elevating, flood proofing (for nonresidential structures), demolishing, or relocating their building or home to meet the requirements of a local community’s building ordinances. This coverage is in addition to the building coverage for the repair of the actual physical damages from flooding. However, the total claims payments cannot exceed statutory limits. Therefore, the maximum amount collectible for both ICC and physical damage from flood for a single family dwelling is $250,000.
3.5 IF A HOUSE WAS BUILT IN COMPLIANCE WITH THE CURRENT EFFECTIVE FIRM AND WAS SUBSTANTIALLY DAMAGED, WOULD ICC COVER THE COST TO ELEVATE THE STRUCTURE TO THE BFE OR ABFE?
Yes, to whichever elevation the community has adopted and is enforcing throughout the community.
3.6 IF A SECOND FLOOR IS ADDED TO THE HOUSE AND THE LOWEST FLOOR IS CONVERTED TO PARKING, STORAGE, OR ACCESS, IS THIS ELEVATION TECHNIQUE ELIGIBLE FOR ICC?
No. ICC is only available if the structure meets the flood insurance policy definition of an elevated building. The flood insurance policy defines an elevated building as “a building that has no basement and that has its lowest elevate floor raised above ground level by foundation walls, shear walls, post, piers, pilings or columns. Solid perimeter foundation walls are not an acceptable means of elevating buildings in V and VE zones.”
3.7 IF A PROPERTY OWNER DEMOLISHES A HOUSE, IS THE PROPERTY OWNER ELIGIBLE FOR UP TO $30,000 TO ELEVATE A NEW HOUSE?
Yes, if the elevation is to the BFE, BFE plus freeboard, or the ABFE as required by the community and the structure is in a mapped floodplain on the current effective FIRM. ICC will cover up to $30,000 for any combination of the following activities:
- Flood proofing (non-residential buildings only)
3.8 IF A COMMUNITY IS DEMOLISHING DAMAGED HOMES, BUT NOT DEMOLISHING THE SLAB, WILL ICC COVER DEMOLISHING THE SLAB?
Yes. ICC will cover the demolition of the slab, but ICC will not cover the demolition cost that has already been paid from another funding source.
3.9 CAN A RESIDENTIAL STRUCTURE BE ELEVATED FOR $30,000?
It depends. There are many factors that affect the costs associated with raising houses. Factors such as size of home, construction type including foundation type, condition and shape of home, condition of slab, elevating utilities, and most importantly the height of elevation, should be considered.
3.10 WHAT OTHER RESOURCES ARE AVAILABLE ON ICC COVERAGE AND STRUCTURAL ELEVATION?
USACE Flood Proofing Publications:
- Raising and Moving a Slab-on-Grade House with Slab, 1990
- Flood Proofing - How to Evaluate Your Options, 1993
- A Flood Proofing Success Story Along Dry Creek at Goodlettsville, Tennessee, 1993
4.1 CAN MY COMMUNITY GET CREDIT UNDER THE NFIP COMMUNITY RATING SYSTEM (CRS) FOR ADOPTING ABFEs OR FREEBOARD?
Yes. Several communities on the New Jersey and New York coast participate in the NFIP’s CRS. Policyholders in these communities receive discounts on their flood insurance premiums because their communities are implementing floodplain management programs that go beyond the minimum requirements of the NFIP. Communities could receive CRS credit for adopting and enforcing ABFEs or for adopting and enforcing freeboard requirements. Credits for adopting ABFEs would be in effect until a revised FIRM became effective. Additional information on CRS can be found at: http://www.fema.gov/national-flood-insurance-program/community-rating-system
Application of ABFEs to FEMA Disaster Grants and Assistance Programs
5.1. WILL FEMA USE ABFEs FOR FEMA RECOVERY AND MITIGATION GRANT PROJECTS?
Yes. FEMA Recovery and Mitigation activities and programs must use the best flood hazard data available prior to obligation of Federal funds.
5.2 WHY MUST FEMA USE ABFEs FOR FEMA DISASTER GRANTS AND ASSISTANCE PROGRAMS?
FEMA is taking action to reduce the risks of flood loss, minimizing impacts of floods on human safety, health, and welfare, and restoring and preserving the natural and beneficial values served by floodplains in carrying out our programs. FEMA grants supporting construction, repair, rehabilitation, and/or improvements in or affecting floodplains are subject to Executive Order 11988, codified in 44 CFR Part 9. FEMA is required to follow an eight-step decision-making process for any action with potential to affect floodplains and must involve the public throughout the decision-making process. FEMA is providing significant investment to help communities recover from the impacts of Hurricane Sandy. FEMA’s responsibility is to ensure the Federal investment is wise, sound, and based on the best scientific information available. This will also increase community resilience related to recovery, siting and evaluation of critical facilities and other FEMA infrastructure restoration projects, and will help guide decisions regarding recovery and hazard mitigation in affected areas to reduce future damages.
5.3 HOW WILL FEMA USE ABFEs IN THE MITIGATION AND RECOVERY PROGRAMS?
FEMA will use ABFEs to determine the flood zone boundaries and minimum flood elevations required for project design and performance standards. This includes the use of ABFEs to determine if a temporary housing activity is located in the floodplain. This applies to placement of temporary housing units (THUs) as well as development of group housing sites and non-traditional types of temporary housing.
5.4 IF LOCAL FLOODPLAIN MANAGEMENT ORDINANCES ARE MORE STRINGENT THAN THE FEMA ABFEs, WHICH STANDARD WILL FEMA USE FOR DISASTER ASSISTANCE AND GRANT DECISIONS?
FEMA-funded grant activities and projects must be consistent with all Federal, State and local requirements, laws and ordinances. If the local codes and standards are more stringent than the ABFE, projects must be designed to the higher standard.
5.5 WHAT HAPPENS IF THE BEST AVAILABLE DATA CHANGES?
It should be expected that what constitutes best available data may change over the course of the recovery process. To be consistent with FEMA regulations (44 CFR 9.11(d)(6), no project shall be built to a floodplain management standard that is inconsistent with the NFIP or less restrictive community floodplain management regulations. That information must be considered when making recovery decisions.
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