revised noaa flood zone maps post hurricane sandy

7/29/2019 Revised NOAA Flood Zone Maps Post Hurricane Sandy

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Luke P Fetten

Geography 176A

Forum Posting

Revised NOAA Flood Zone Maps Post Hurricane Sandy

On October 29, 2012, Hurricane Sandy made landfall as a Category 1

hurricane just north of Atlantic City, New Jersey after an interesting week of

unpredictability. The storm became the second costliest storm bringing over 68

billion dollars in damage to 24 states. In the hours leading up to landfall GIS analysts

crunched numbers and applied models to accurately depict flood zones as a result of

storm surges and rainfall. Several months after, these same GIS professionals are

working with FEMA, NOAA, and the New Jersey Department of Environmental

Protection to revise old flood maps to more accurately depict the true flood zones.

Immediately after the storm, Advisory Base Flood Evaluations (ABFEs) were

released to give the most up to date flood hazard data that was available for

communities and individuals to properly rebuild damaged properties. On June 17,

2013, preliminary work maps were released to show changes in the ABFEs with

more accurate data. These maps show in layers the old ABFE and the new

preliminary ABFE and what flood zone the polygon enclosed areas are apart of. Zone

V/VE is an area of high flood risk subject to inundation by the 1% annual-chance

flood event with additional hazards due to storm-induced velocity wave action, a 3

foot or higher breaking wave. Zone A/AE is an area of high flood risk subject to

inundation by the 1% annual-chance flood event determined by detailed methods.

Zone AO is an area of high flood risk subject to inundation by 1% annual-chance

shallow flooding where average depths are between one and three feet. Average

flood depths derived from detailed hydraulic analyses are shown in this zone.

Shaded Zone X is an area of moderate coastal flood risk outside the regulatory 1%annual chance flood up to the 0.2% annual chance flood level. Based on the new

preliminary ABFE maps many changes have been made. A few screenshots are

shown below of the Sea Bright Police Department and the flood zone maps for that

location before and after re-evaluation as well as a few photos of the damage there.

These maps will dictate how people are allowed to build in flood zone areas. Some


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areas have lost flood zone status are have a decreased risk much like the examples

below, but many places have a much higher risk associated with them.

New Preliminary ABFE Work Map from Region2Coast.com:


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Preliminary ABFE from FEMA ArcGIS:

Original ABFE from FEMA ArcGIS:


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Damage Post Sandy at Sea Bright:


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Sources:

http://www.region2coastal.com/coastal-mapping-basics

http://www.region2coastal.com/sandy/table
http://www.region2coastal.com/coastal-mapping-basicshttp://www.region2coastal.com/coastal-mapping-basicshttp://www.region2coastal.com/sandy/tablehttp://www.region2coastal.com/sandy/tablehttp://www.region2coastal.com/sandy/tablehttp://www.region2coastal.com/coastal-mapping-basics


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http://fema.maps.arcgis.com/home/webmap/viewer.html?webmap=2f0a884bfb43

4d76af8c15c26541a545

http://www.state.nj.us/dep/gis/gisemerresp.html

http://gcn.com/Articles/2013/02/27/FEMA-emergency-data-available-real-

time.aspx?Page=1

http://www.nj.com/news/index.ssf/2013/06/new_flood_maps_shrink_riskiest_are

as_in_4_nj_counties_by_at_least_45_percent.html
http://fema.maps.arcgis.com/home/webmap/viewer.html?webmap=2f0a884bfb434d76af8c15c26541a545http://fema.maps.arcgis.com/home/webmap/viewer.html?webmap=2f0a884bfb434d76af8c15c26541a545http://fema.maps.arcgis.com/home/webmap/viewer.html?webmap=2f0a884bfb434d76af8c15c26541a545http://www.state.nj.us/dep/gis/gisemerresp.htmlhttp://www.state.nj.us/dep/gis/gisemerresp.htmlhttp://gcn.com/Articles/2013/02/27/FEMA-emergency-data-available-real-time.aspx?Page=1http://gcn.com/Articles/2013/02/27/FEMA-emergency-data-available-real-time.aspx?Page=1http://gcn.com/Articles/2013/02/27/FEMA-emergency-data-available-real-time.aspx?Page=1http://www.nj.com/news/index.ssf/2013/06/new_flood_maps_shrink_riskiest_areas_in_4_nj_counties_by_at_least_45_percent.htmlhttp://www.nj.com/news/index.ssf/2013/06/new_flood_maps_shrink_riskiest_areas_in_4_nj_counties_by_at_least_45_percent.htmlhttp://www.nj.com/news/index.ssf/2013/06/new_flood_maps_shrink_riskiest_areas_in_4_nj_counties_by_at_least_45_percent.htmlhttp://www.nj.com/news/index.ssf/2013/06/new_flood_maps_shrink_riskiest_areas_in_4_nj_counties_by_at_least_45_percent.htmlhttp://www.nj.com/news/index.ssf/2013/06/new_flood_maps_shrink_riskiest_areas_in_4_nj_counties_by_at_least_45_percent.htmlhttp://gcn.com/Articles/2013/02/27/FEMA-emergency-data-available-real-time.aspx?Page=1http://gcn.com/Articles/2013/02/27/FEMA-emergency-data-available-real-time.aspx?Page=1http://www.state.nj.us/dep/gis/gisemerresp.htmlhttp://fema.maps.arcgis.com/home/webmap/viewer.html?webmap=2f0a884bfb434d76af8c15c26541a545http://fema.maps.arcgis.com/home/webmap/viewer.html?webmap=2f0a884bfb434d76af8c15c26541a545

revised noaa flood zone maps post hurricane sandy

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