Delaware Flood Planning Tool

Overview

The Delaware Department of Natural Resources and Environmental Control (DNREC) Flood Tool is an interactive web map application. This tool is designed to aid you in researching your flood risk in the state of Delaware. It is designed to provide floodplain managers, insurance agents, developers, real estate agents, engineers, surveyors, local planners and citizens with an effective means by which to make informed decisions about the degree of flood risk for a specific area or property. Map features are connected to geospatial databases that may be queried by users in order to obtain pertinent information that may otherwise be difficult to obtain or relate to specific geographic locations, such as the Advisory Flood Height (AFH) for flood Zone A and downloadable HEC-RAS models.

The online tool is for use in administering the National Flood Insurance Program. It does not necessarily identify all areas subject to flooding, particularly from local drainage sources of small size. To obtain more detailed information in areas where Base Flood Elevations have been determined, users are encouraged to consult the latest flood profile data contained in the official Flood Insurance Study (FIS). These studies are available online at www.msc.fema.gov.

Advisory Flood Height (AFH)

Advisory Flood Height (AFH) represents the elevation of the surface of the 1% annual chance or regulatory flood in Zone A (approximate study) modeled areas. The AFH value for a given location serves as a surrogate base flood elevation (BFE) when the latter is not available. AFH data are subject to limitations such as: no hydraulic structures (bridges/culverts/dams) are considered, no reservoir routing/attenuation of flood discharges are incorporated and no channel survey data are included. Therefore, AFH’s may be inaccurate especially near structures.

Disclaimer

The Flood Tool provided herein is for reference only within the State of Delaware boundaries. The user of this information understands and acknowledges that the data may be inaccurate or contain errors or omissions and the user assumes full responsibility for any risks or damages resulting from any use of or reliance upon this data. Delaware DNREC does not guarantee the accuracy or reliability of the data generated from this service.


Parcel Examples:
New Castle County: 1502400103
Kent County: 3-01-01700-02-2901-00001
Sussex County: 123-16.00-950.00

Address Search Disclamer
For more information please contact:

Janice Shute, PE: janice.shute[at]state.de.us

For a list of contacts by community: Community Contact List

Getting Started

  • Identify your location by navigating the map and using the plus/minus buttons or searching an address, watershed or parcel by entering the information in the Search tool located in the ‘Search’ tab on the left navigator tab.
  • Display the floodplain results by clicking the location on the map or selecting the ‘Results’ tab on the left navigation tabs if the location has already been selected.

Additional Tools and Information

  • The Results tab identifies if the location selected is within the FEMA 100-year floodplain and other parcel specific information.
  • The Legend Tab defines the features used within the map and presents the user the ability to turn on and off the various feature layers. The transparency of the ‘Effective Flood Insurance Rate’ and ‘Preliminary Flood Insurance Rate Map’ layers can also be adjusted here.
  • The Basemap can be changed by clicking the Satellite/Gray button in upper right corner to toggle between gray scale map and aerial imagery backgrounds.
  • The Print Tab contains a ‘Print’ button that will compile a PDF printout that can be saved or printed. Upon completion, click the “Printout” link to open or print the pdf. * Printout will display exactly the layers that are being shown in the tool when the printout is created. If you want bot Effective and Preliminary layers to show you will need to make sure both layers are turned on.
  • Contacts Tab displays a contact for help/information about the tool and a link to the Floodplain Management contacts for each community.

HOW TO USE DRAFT/PRELIMINARY DATA

For FEMA guidance on use of draft or preliminary FIS data use the following link: http://www.fema.gov/use-flood-insurance-study-data-available-data

Advisory Flood Height (AFH)

AFH The elevation in feet of the 1 percent annual chance flood

AFH – CAUTION CAUTION!! The advisory flood height listed CANNOT be used in proximity to a culvert, bridge or other stream crossing. Also, if the site is close to the confluence with a larger stream check the AFH or BFE on the larger stream to see if the site is within the backwater of the 1% annual chance flood elevation of that larger stream.