Lafourche Parish, Louisiana
FEMA has developed Hurricane Rita Surge Inundation and Advisory Base Flood Elevation Maps (referred to as, “Rita Recovery Maps”) to aid Lafourche Parish property owners to repair or rebuild structures to newly determined advisory coastal flood elevations. These maps are based on Flood Recovery Guidance for Lafourche Parish (PDF, 118 KB) that FEMA published in November 2005.
Frequently Asked Questions
- How do I find the Rita Recovery Map that shows my property?
- How do I determine what Advisory Base Flood Elevation (ABFE) applies to my property?
- I know my ABFE. How high above ground does this mean I have to elevate my structure?
- How did FEMA determine what areas got flooded by Hurricane Rita’s storm surge, and should I be concerned if I think the surge limits are inaccurate?
To locate a particular property, the first step is to determine which detailed Rita Recovery Map panel applies to the area of interest. Users should first consult the Lafourche Parish Index Map (PDF, 1.1 MB), which shows which panels were produced and what area is covered by each. Panel numbers are shown in green text (e.g., PP25). Panels were only produced for areas where structures or other significant development could be observed on recent aerial photography.
Once the detailed Rita Recovery Map panel number is known, it can be opened by clicking on the corresponding panel number on the parish map immediately below. The panel will open up in the internet browser window using the Adobe Acrobat Reader software. The Rita Recovery Map panels range in size from 1.1 MB to 2.1 MB.
AA99 AA100 AA101 AA102 AA103 AA104 AA105 AA109
Z96 Z97 Z98 Z99 Z100 Z101 Z102 Z103 Z104 Z105 Z106 Z107 Z108 Z110
Y96 Y97 Y98 Y99 Y100 Y101 Y103 Y104 Y105 Y106 Y107 Y110
X97 X98 X99 X100 X101 X103 X107 X109 X110 X111 X112
W94 W95 W96 W97 W98 W99 W100 W101 W102 W103 W104 W105 W106 W107 W108 W112 W113
V95 V96 V100 V101 V102 V103 V104 V105 V106 V107 V108 V109 V114
U94 U95 U96 U97 U101 U102 U103 U104 U105 U106 U107 U108 U109 U110 U111 U112 U114
T102 T103 T104 T105 T106 T107 T108 T109 T111 T112 T113
S103 S104 S105 S106 S107 S108 S109 S110 S111 S116 S117 S118
R104 R105 R106 R107 R108 R109 R110 R111 R112 R113 R114 R115
Q106 Q107 Q108 Q110 Q111 Q112 Q113 Q114 Q115
P107 P108 P109 P110 P111 P112 P113 P114 P115 P116 P117
O108 O109 O110 O114 O116 O117
N109 N114 N115 N116 N117
M110 M115 M117
L111 L115 L116
K114 K116 K117 K118
J115 J117 J118
D119 D120 D121 D122 D123
B118 B119 B120
Rita Recovery Maps are for advisory purposes only; they do not supersede effective Flood Insurance Rate Maps (FIRMs). The Hurricane Rita-related data presented are preliminary and subject to update as additional data become available.
The Rita Recovery Maps depict ABFEs (that is, elevations that FEMA recommends be used for rebuilding) for defined areas or zones. The visual appearance of these advisory zones and elevations was intentionally made similar to the format of flood hazard data shown FEMA’s FIRMs. [Note: Individuals unfamiliar with FIRMs can view the online tutorial, “How to Read a Flood Insurance Rate Map (FIRM).”]
On the Rita Recovery Maps, each ABFE zone is outlined in yellow and is labeled with the applicable advisory flood zone type and whole-foot elevation (e.g., ABFE Zone VE Elevation 16). ABFEs are measured relative to the National Geodetic Vertical Datum of 1929 (NGVD29), or roughly sea level. The whole-foot ABFE listed on each contour can be directly applied to properties located within the zone. On some maps, a thick yellow line marks the inland limit of the ABFEs; landward of this line, ABFEs do not apply.
Since the ABFEs are measured relative to NGVD29 (or roughly sea level), property owners will need ground elevations to determine how high above grade a structure should be elevated to meet the ABFE. Property owners are advised to consult with a licensed surveyor or professional engineer to determine ground elevations at their site. Once the ground elevation is known, it can be subtracted from the ABFE to calculate the height above grade that a structure’s first floor (in A Zones) or lowest horizontal structural member (in V Zones) should be elevated.
How did FEMA determine what areas got flooded by Hurricane Rita’s storm surge, and should I be concerned if I think the surge limits are inaccurate?
FEMA used the best data available at the time the recovery mapping was completed to estimate the extent and magnitude of Hurricane Rita’s storm surge. To develop this data layer, surge-only High Water Marks (HWMs) collected by FEMA shortly after the storm were compared to detailed, pre-storm topographic data provided by the State of Louisiana. In some areas, few or no HWMs were available to help guide the mapping; in these cases, surge inundation limits were interpolated from more distant HWMs, with coastal engineering judgment and eyewitness accounts (when available) used to complete the mapping. As a result of these and other data limitations, the mapped Rita surge limits may over- or underestimate the actual coastal flooding that occurred.
The ABFEs, not the estimated Rita surge limits or surge heights, are what FEMA is advising be used for rebuilding, so there should be no negative impact on property owners if the Rita limits were over- or underestimated. If property owners have detailed documentation concerning the height and/or extent of Rita’s surge flooding that differs from the data shown on the Rita Recovery Maps, they can submit this information through the recovery mapping helpline link listed below. Unless there becomes a need to completely reanalyze the Rita surge and remap large areas, FEMA will only be able to use submitted information to help improve the surge inundation modeling and mapping procedures for future recovery mapping efforts.