Southwest Florida - Hernando County

Floodplain Justification Report
Hernando County, Florida
Centralia Watershed (B206)
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TABLE OF CONTENTS
1.0 INTRODUCTION ___________________________________________ 1
2.0 GUIDELINES & SPECIFICATIONS _____________________________ 1
3.0 WATERSHED DESCRIPTION _________________________________ 1
4.0 FLOODPLAIN MODEL DEVELOPMENT METHODOLOGY _________ 2
5.0 VERIFICATION & VALIDATION DATA _________________________ 12
6.0 MODELED FLOODPLAINS __________________________________ 14
7.0 FLOODPLAIN JUSTIFICATION _______________________________ 15
8.0 PUBLIC MEETING _________________________________________ 16
9.0 CONCLUSION ____________________________________________ 16
10.0 REFERENCES _____________________________________________ 16
ATTACHMENTS
FIGURES
TABLES
EXHIBITS
Figure 1 - Location Map
Figure 2 - Existing FEMA Floodplain
Figure 3 - 1960 Potentiometric Surface Above Land Surface
Figure 4 - Western Region Floodplain Comparisons
Figure 5 - Corresponding Land Surface and 1960 Potentiometric Surface
Figure 6 - Evaluation Areas for Multi-Day
Figure 7 - Projected 1- and 5-day Elevation Comparison
Figure 8 - Two-Sink Area Investigation
Figure 9 - Catchments Selected for Multi-Day Assignment
Figure 10 - Well Levels
Figure 11 - Withlacoochee River and Weeki Wachee Well Levels
Figure 12 - 1960 Potentiometric Surface Overlain On To 1970 Aerial Photos
Figure 13 - Centralia Romp Well with Historic Contours
Figure 14 - Pasco 16 Well
Figure 15 - Modeled 100-Year/24-Hour Floodplain
Table 1 - Floodplain Justification Summary
Exhibit – Model Map
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Southwest Florida Water Management District December 2, 2009