Hurricane Rita Surge Inundation & Advisory Base Flood Elevation Maps

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Terrebonne Parish, Louisiana

FEMA has developed Hurricane Rita Surge Inundation and Advisory Base Flood Elevation Maps (referred to as, “Rita Recovery Maps”) to aid Terrebonne Parish property owners to repair or rebuild structures to newly determined advisory coastal flood elevations. These maps are based on Flood Recovery Guidance for Terrebonne 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?

Terrebonne Parish Image Map Thumbnail

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 Terrebonne Parish Index Map (PDF, 1.3 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 1.0 MB to 2.1 MB.

Recovery map of Terrebonne Parish, North

W99
V98 V99 V100 V101
U94 U95 U96 U97 U99
T93 T94 T97 T99 T101 T102 T103
S91 S94 S95 S96 S98 S99 S100 S101 S102 S103 S104
R87 R88 R96 R97 R98 R99 R100 R101 R102 R103 R104 R105 R106
Q87 Q99 Q100 Q101 Q102 Q103 Q104 Q105 Q106 Q107
P86 P87 P100 P101 P102 P103 P104 P105 P106 P107 P108
O101 O102 O104 O105 O106 O107 O108 O109
N100 N101 N102 N103 N104 N106 N107 N108 N109 N110

Recovery map of Terrebonne Parish, South

M96 M99 M100 M101 M102 M103 M106 M107 M108 M109 M110 M111
L95 L97 L99 L100 L101 L102 L103 L106 L107 L108 L111
K93 K94 K96 K97 K99 K100 K103 K105 K106 K107 K110
J94 J95 J96 J99 J100 J102 J103 J105 J106
I95 I97 I98 I99 I102 I103 I105
H102 H103 H104 H105
G94 G95 G96 G97 G104 G105
F104
E102 E103
C97

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.

How do I determine what Advisory Base Flood Elevation (ABFE) applies to my property?

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.

I know my ABFE. How high above ground does this mean I have to elevate my structure?

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

Last Updated: 
07/24/2014 - 16:00
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