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Large Area Mapping Initiative, Nebraska

NEBRASKA  - Through the Cooperating Technical Partnership program, the Nebraska Department of Natural Resources (NDNR) developed the Large Area Mapping Initiative to map unstudied areas in the state as a means of providing flood hazard data to all users. Coordinated with FEMA, the results of the initiative provide a complete set of data to floodplain managers for use in the administration of the National Flood Insurance Program (NFIP).

Until five years ago, not all Special Flood Hazard Areas (areas subject to inundation by the base, or 100-year flood) within the State of Nebraska had been identified. The NDNR requires that flood hazard data be provided to its citizens. This requirement, coupled with the need to assist communities in the NFIP, provided the incentive to enter into a partnership with FEMA to provide flood hazard data to all users in the state.

Using a geographic information system (GIS), the State developed software to delineate flood hazard areas. The method is largely automated, making the process more efficient, and less expensive than traditional study methods. In the last three years, 19 counties have been mapped using this method. The delineations are approximate, but a user can input flood stage data to calculate a Base Flood Elevation (BFE) for use in floodplain development.

FEMA and the State are working together to produce official FEMA flood maps from these studies. In the meantime, many communities in the NFIP have adopted the working maps as best available data, and use the BFE information for floodplain management.

The State will continue to work with the communities to help them adopt the working maps for use in floodplain management. Even after the maps are published as the official, effective FEMA flood hazard, the additional flood elevation data generated by Nebraska’s automated processes will continue to benefit communities.

“This mapping effort would have been impossible without the strong partnership between the State of Nebraska and the Federal Emergency Management Agency, through the Cooperating Technical Partners program.” --Roger Patterson, P.E., Director, NDNR.

Last updated June 3, 2020