FEMA uses the Coordinated Needs Management Strategy (CNMS) to identify and track the lifecycle of mapping needs of the flood hazard mapping program. The CNMS Viewer provides a map view of the inventory of FEMA’s flood hazard study and mapping needs for areas where an updated study is needed. The CNMS Viewer supports community officials and FEMA management and staff in analyzing and depicting flood risk studies validity to enhance understanding of flood hazard risk and make informed decisions on community planning and flood mitigation.
FEMA administers the National Flood Insurance Program (NFIP) and provides flood hazard data and maps nationwide. As floodplains are constantly changing, Flood Insurance Rate Maps (FIRMs) are updated to reflect physiological, climatological, and engineering methodology (PCE) changes.
To maintain the validity of flood hazard data over time, FEMA assesses the inventory of FIRMs and its underlying flood risk studies to determine whether conditions on the ground are still adequately represented on the FIRM panels for that area. When the flood information on the FIRM does not adequately represent actual conditions, it is considered a “flood hazard mapping need” and a new or updated flood hazard study for the area may be warranted. Through the CNMS Viewer, FEMA identifies and tracks the lifecycle of mapping needs of the flood hazard mapping program.
View CNMS Data in the GIS Viewer
The CNMS Viewer provides a single location to view the inventory of studies and mapping needs. In addition, users can view the validity of a flood hazard study and understand if an area is New, Valid, and Updated Engineering (NVUE) compliant, meaning the studies were completed using up-to-date engineering methodology and/or conducted in areas where significant PCE changes have not occurred since the date of the FIRM and its original study.
Below is an image of data populated in the CNMS Viewer. Colored stream centerlines display the validation status of flood hazard studies in the FEMA CNMS Inventory, while polygons are used to hold the supporting data used to make the validation decisions.
Understanding the Validation Process
FEMA re-evaluates all flood hazard studies every five years. The CNMS Validation process evaluates a flood hazard study against 17 factors used to represent possible Physiological, Climatological, and Engineering methodology (PCE) changes that may have occurred since the date the FIRM took effect and its original study date. These may include changes in land use, new/removed bridges and/or culverts, and recent floods. Each study is assigned a validation status (i.e. Valid, Unverified, Unknown, or Assessed).
Valid flood hazard studies are also referred to as being “NVUE compliant.” A study that does not pass the validity checks is assigned an “Unverified” status; such flood hazard study areas may either be eligible to receive resources for a restudy or a restudy may already be underway to regain its compliant status. An “Unknown” status indicates that a study is being evaluated, an evaluation is planned, or insufficient information is available to determine validation status. An “Assessed” status indicates that an evaluation of a flood hazard study has recently been completed and the study meets current validity standards. In all cases, the flood hazard information on the FIRM shall be used as the regulatory standard for floodplain management purposes regardless of validation status.
Users may find that viewing the validation status types is useful for tracking and making informed map update investment decisions. Viewing the validation status types also may enhance data-driven planning activities for map update prioritization efforts.
For more information about flood hazard mapping, floodplain management, or other information provided on this page, contact a Map Specialist in the FEMA Map Information eXchange (FMIX) by: