Project Overview

ATM successfully prepared an appeal of the preliminary FEMA Flood Insurance Rate Map (FIRM) that resulted in moving a portion of the primary frontal dune out of the VE Zone.

Summary

ATM reassessed the landward location of the VE zone determined by FEMA on the revised Flood Insurance Rate Maps (FIRM). Marineland Dolphin Adventure is located behind a granite revetment designed for a 30-year storm event and the landward extent of the VE zone was based on the assumption of the existence of primary frontal dune (PFD) at this site. To assess the potential for moving the VE line west and account for protection afforded by the revetment, ATM initiated a preliminary study that required review of:

• Preliminary FIS report for St. Johns County
• FEMA Wave model (WHAFIS) transects
• LiDAR/DEM data used in the models
• Revetment design and PFD occurrence and characteristics in LiDAR and survey data.

ATM determined there were potential items of appeal that would support a request to relocate the VE zone boundary. As part of the successful appeal package submitted to FEMA, ATM:

• Conducted a detailed review of FEMA preliminary data and historic data
• Performed a partial revetment failure and wave runup analysis
• Re-ran WHAFIS runs with better site-specific information
• Created a revised map and completed a PFD appeal package