Preliminary Work Maps: Frequently Asked Questions
The New Jersey/New York coastal flood study was underway when Hurricane Sandy struck the region in October 2012. Following Sandy, FEMA released Advisory Base Flood Elevation (ABFE) maps for certain communities based on the partially completed flood study which were designed to help in rebuilding and recovery efforts. In 2013, FEMA began issuing preliminary work maps which included the full results of the coastal flood study.
For most communities in the region, both the ABFE maps and preliminary work maps have now been replaced by preliminary FIRMs as the most recent flood hazard information available from FEMA. An historical archive of all ABFE and preliminary work map information released is available through the FEMA Best Available Data archive page. More information about the preliminary work maps is also available through the FAQ below and in the Document Library.
What are preliminary work maps?
The preliminary work maps created for certain New Jersey/New York communities are an interim product created by FEMA in the development of preliminary Flood Insurance Rate Maps (FIRMs). The preliminary work maps reflect the results of an ongoing coastal flood hazard study for the New York/New Jersey coast. This information replaced the Advisory Base Flood Elevation (ABFE) maps that were prepared for some communities for rebuilding and recovery efforts in the aftermath of Sandy as the most recent data available from FEMA.
The preliminary work maps are intended to help communities and property owners understand current flood risk and likely flood insurance requirements in the future. The release of this information will also provide local officials an opportunity to review and comment on areas in their community where they believe risks are inappropriately mapped (understated or overstated). By identifying concerns early in the map development process, FEMA can avoid delays and costly revisions to the preliminary FIRMs following their release.
Where can I get the preliminary work maps?
For most communities in the region, the preliminary maps have now been replaced by preliminary FIRMs as the most recent flood hazard information available from FEMA. An historical archive of all preliminary work map information released is available through the FEMA Best Available Data archive page.
What is the difference between the preliminary work maps and the ABFE maps?
The ABFE maps were based on the partially completed coastal flood study underway when Sandy occurred and were intended to serve as an interim product while the updated coastal flood hazard analyses were completed. The preliminary work maps, which replace the ABFE maps as the most recent data available from FEMA, are based on the same underlying data as the ABFE maps, but use a more refined analysis of shoreline conditions along the impacted coastal area, including the effects of erosion and wave runup. Information about the coastal modeling techniques used to prepare the preliminary work maps is available on the Coastal Mapping Basics page of this website.
Are the preliminary work maps the same thing as the preliminary FIRM?
No. The preliminary work maps are an interim or “draft” product that FEMA is sharing with communities in advance of the release of the preliminary FIRMs to get early input on the mapping and underlying data. The preliminary work maps represent the same coastal flood elevation and zone data as the preliminary FIRMs but lack certain map legend, notes, and other details included in FIRM products.
Additionally, for most communities, the preliminary work maps will include coastal flood hazard areas only. In most communities, the work maps will not show updates to riverine flood hazards which may be occurring and the tie-ins between riverine and coastal flood hazard information. However, all information for both coastal and non-coastal areas will be included on the preliminary FIRMs.
Were the effects of Sandy taken into account when developing the preliminary work maps?
Because no storm affects all areas in the same way, FEMA does not take into consideration the effects of a specific storm to produce flood hazard information. Rather, FEMA’s engineering studies develop a long-term projection of flood hazards based on data such as overland wave modeling and storm-induced erosion analyses. The preliminary work maps do include the Sandy high-water mark elevations in some areas based on data collected by the U.S. Geologic Survey (USGS). These data are shown for informational purposes and are not intended to be used to validate the coastal mapping or the coastal Base Flood Elevations (BFEs).