Data Development/Floodplain Mapping

• Depending on the scope of the project, the project team members complete some or all of the following tasks during this phase of the project:

1. Develop and/or obtain topographic and cross-section data needed for engineering analyses and floodplain boundary delineations.
2. Perform engineering analyses—called hydrologic or hydraulic analyses—of riverine flooding sources.
3. Perform coastal engineering analyses for areas located along the Atlantic or Pacific Oceans, Gulf of Mexico, or Great Lakes.
4. Delineate flood hazard boundaries and identify flood insurance risk zones.
5. Obtain and prepare the base map to be used for production.
6. Digitize directly from the current effective FIRM panels those flood hazard and regulatory floodway boundaries that are not being updated.
7. "Merge" new or updated flood hazard data (for updated portions of flooding sources) with effective flood hazard data (for non-revised portions of flooding sources) to produce the new or updated DFIRM
8. Collect all required information in the Geographic Information System (GIS)-based DFIRM Database.
9. Compile the FIS report.
10. Produce and distribute hard copy (paper) and digital copies of the Preliminary versions of the DFIRM and FIS report.

For the mapping project for Hancock, Harrison, and Jackson Counties, all of the tasks above were performed.

• To compress timeframes, many work elements during this phase are completed concurrently and collaboratively by the project team members. Such was the case with the work performed for this mapping project. MEMA, MDEQ, and their contractors—who had started their work on the engineering analyses and mapping for the interior areas of Hancock, Harrison, and Jackson Counties before Hurricane Katrina wreaked havoc on the region—were able to continue their work while FEMA and the FEMA contractor performed the detailed coastal engineering analyses on the Gulf of Mexico.

Additional information on data development and map production is provided in Volume 1, Section 1.4, and several of the appendices in FEMA’s Guidelines and Specifications for Flood Hazard Mapping Partners.

Back to the Calendar/Schedule page.