Hazard Mitigation Technical Assistance Program
Contract No. EMW-2000-CO-0247
Task Order 415
Hurricane Katrina Rapid Response
Wind Water Line (WWL) Data Collection  Louisiana
FEMA-1603-DR-LA
Final Report
June 9, 2006
Submitted to:
Federal Emergency Management Agency
Region IV
Atlanta, GA
Prepared by:
URS Group, Inc.
200 Orchard Ridge Drive
Suite 101
Gaithersburg, MD  20878
FOR PUBLIC RELEASE
Table of Contents
Abbreviations and Acronyms	iii
Glossary of Terms	iv
Background	1
Overview of Impacts in Louisiana	3
Purpose	11
Methodology	15
Findings and Observations	25
Conclusion	31
List of Figures
Figure 1: Hurricane Katrina Storm Track	1
Figure 2: FEMA-1603-DR-LA Disaster Declaration	5
Figure 3: New Orleans Area Levee Breaches	7
Figure 4: Southern Breach in the East Floodwall and Levee of the Industrial Canal	8
Figure 5: New Orleans 17th Street Canal at Old Hammond Highway Bridge	8
Figure 6: Photograph of Flooded Homes along New Orleans Levee	9
Figure 7: WWL Study Area within Louisiana	13
Figure 8: WWL Illustration (Profile View/Plan View)	16
Figure 9: WWL Data Point Distribution	17
Figure 10: Example of a Debris Line	19
Figure 11: Example of an HWM	19
Figure 12: HWMs Used to Help Delineate the WWL	21
List of Tables
Table 1: Parishes Designated for IA and PA 	3
Table 2: Parishes Designated for IA and PA  Categories A and B Only 	4
Table 3: Parishes Designated for PA  Category B Only 	4
Table 4: HWMs Used to Help Delineate the WWL	21
Table 5: HWM Data Points Used as WWL Data Points	22
Table 6. CHWM Points Used to Determine the Inland Extent of Surge Flooding
along the Pearl River 	22
Table 7. CHWM Points Used to Determine the Inland Extent of Surge Flooding
along the Mississippi River 	23
Table 8: Summary of Flood Sources and Map Sheets by Parish	25
Appendices
Appendix A: WWL Data Points	APPENDIX A NOT INCLUDED DUE TO PRIVACY ISSUES
Appendix B: WWL Photographs	APPENDIX B NOT INCLUDED DUE TO PRIVACY ISSUES
Appendix C: Debris Line and Inundation Mapping Report: HMTAP Task Order 411, Rapid
Response, Aerial Radar  Louisiana, Mississippi, and Alabama
Appendix D: Notes on Analysis of WWL Data Points
Appendix E: WWL Maps
ABBREVIATIONS AND ACRONYMS
Acronyms
Explanation
CDT
Central Daylight Time (daylight savings time zone)
CHWM
Coastal High Water Mark
DEM
Digital Elevation Model
EDT
Eastern Daylight Time (daylight savings time zone)
FEMA
Federal Emergency Management Agency
FIRM
Flood Insurance Rate Map
GIS
Geographic Information System
GPS
Global Positioning System
HMGP
Hazard Mitigation Grant Program
HMTAP
Hazard Mitigation Technical Assistance Program
HWM
High Water Mark
IA
Individual Assistance
kts
Knots
LiDAR
Light Detection and Ranging or Laser Imaging Detection and Ranging
mb
Millibar
mph
Miles Per Hour
NAD 83
North American Datum of 1983
NAVD 88
North American Vertical Datum of 1988
NCDC
National Climatic Data Center
NFIP
National Flood Insurance Program
NGS
National Geodetic Survey
NGVD 29
National Geodetic Vertical Datum of 1929
NWI
National Wetlands Inventory
PA
Public Assistance
PNP
Private Non-Profit
RHWM
Riverine High Water Mark
USGS
United States Geological Survey
UTM
Universal Transverse Mercator
WWL
Wind Water Line
GLOSSARY OF TERMS
Word
Definition
ArcCatalog
Software application from ESRI that organizes and manages all
Geographic Information System (GIS) information such as maps,
globes, data sets, models, metadata, and services.
ArcGIS
The comprehensive name for the current suite of GIS products
produced by ESRI that are used to create, import, edit, query, map,
analyze, and publish geographic information.
ArcView
A software application from ESRI that provides extensive mapping,
data use, and analysis, along with simple editing and geoprocessing
capabilities.
Base map
A map or chart showing certain fundamental information, used as a
base upon which additional data of a specialized nature are
compiled or overprinted.
Contour data
All the information required to create lines of equal elevation on a
map. These are referred to as contour lines on topographic maps
and are used to describe land forms based on elevation above a
defined vertical datum.
Contour lines
Lines that connect a series of points of equal ground elevation and
are used to illustrate topography, or relief, on a map.
Data point
A point associated with a discrete geographic location where data
pertaining to the study were collected.
Debris line
Defines the extent of flooding where debris such as parts of houses,
docks, cars, or other non-natural material is generally carried by
floodwaters with some velocity and is then dropped as the
floodwaters lose velocity and begin to recede.
Disaster declaration
The formal action by the President to make a state eligible for major
disaster or emergency assistance under the Stafford Act.
Emergency protective
measures
Actions taken by Applicants before, during, and after a disaster to
save lives, protect public health and safety, and prevent damage to
improved public and private property.
Flood recovery map
High-resolution maps that show flood impacts, including high water
mark (HWM) flood elevations, flood inundation limits, the inland limit
of waterborne debris (trash lines), and storm surge elevation
contours based on the HWMs. The maps also show existing FEMA
Flood Insurance Rate Map (FIRM) flood elevations for comparison to
hurricane data.
Geodatabase
The geodatabase provides the common data access and
management framework for ArcGIS. Geodatabases organize
geographic data into a hierarchy of data objects. These objects are
stored in feature classes, object classes, and feature datasets. An
object class is a table in the geodatabase that stores nonspatial
data. A feature class is a collection of features with the same type of
geometry and the same attributes. A feature dataset is a collection
of feature classes sharing the same spatial reference.
Hazard Mitigation Grant
Program
Provides grants to states and local government to implement long-
term hazard mitigation measures after a major disaster declaration.
The purpose of the program is to reduce the loss of life and property
due to natural disasters and to enable mitigation measures to be
implemented during the immediate recovery from a disaster.
Individual Assistance
Federal assistance provided to families or individuals following a
major disaster or emergency declaration. Under a major disaster
declaration, assistance to individuals and families is available
through grants, loans, and other services offered by various Federal,
state, local, and voluntary agencies.
Infrastructure
The basic facilities, services, and installations needed for the
functioning of a community or society, such as transportation and
communications systems, and water and power lines.
Inundated
Flooded or covered with water.
Inundation polygon
Aerial extent of flooding as shown by polygon feature in ArcGIS.
Knot
A unit of speed, one nautical mile per hour, approximately 1.85
kilometers (1.15 statute miles) per hour.
LiDAR
A technology that determines distance to an object or surface using
laser pulses. Like the similar radar technology, which uses radio
waves instead of light, the range to an object is determined by
measuring the time delay between transmission of a pulse and
detection of the reflected signal.
Millibar
A unit of atmospheric pressure equal to one thousandth of a bar.
Standard atmospheric pressure at sea level is about 1,013 millibars.
Mitigation
Any measure that will reduce or eliminate the long-term risk to life
and property from a disaster event.
National Flood Insurance
Program
The Federal program created by an Act of Congress in 1968 that
makes flood insurance available in communities that enact and
enforce satisfactory floodplain management regulations.
National Geodetic Vertical
Datum of 1929
Vertical control datum that was widely used in the U.S. prior to the
establishment of NAVD 88.
North American Datum of 1983
Horizontal datum used as the standard map coordinate system
default by the majority of Global Positioning System (GPS) devices.
North American Vertical Datum
of 1988
The most widely used vertical control datum in the U.S. today, it was
officially established in 1991 by the minimum-constraint adjustment
of the Canadian-Mexican-U.S. leveling observations.
Orthorectification
Process by which the effects of relief displacement and imaging
geometry are removed from aerial photographs. These adjustments
are made to correct for the natural distortions caused by the
perspective of the aircraft or spacecraft that took the photographs,
and recreate the ground geometry in the imagery as it would appear
from directly above each point in the photograph. From this process,
orthophotos are created, which generally have the same geometric
characteristics as topographic maps.
Polygon
In ArcGIS, a shape defined by one or more rings, where a ring is a
path that starts and ends at the same point. If a polygon has more
than one ring, the rings may be separate from one another or they
may nest inside one another, but they may not overlap.
Public Assistance
Federal assistance provided to state and local government, Native
American Tribes, and certain non-profit organizations after a disaster
declaration. The assistance is for the repair, replacement, or
restoration of disaster-damaged, publicly owned facilities and the
facilities of certain Private Non-Profit (PNP) organizations. The
Federal share of assistance is not less than 75 percent of the eligible
cost for emergency measures and permanent restoration. The state
determines how the non-Federal share (up to 25 percent) is split
with the applicants.
Riverine flooding
Occurs when rivers and streams overflow their banks.
Seed file
Used within software applications and serve as templates in which
standard file parameters are set to predetermined standards.
Shapefile
Stores geographic features and their attributes. Geographic features
in a shapefile can be represented by points, lines, or polygons
(areas).
Storm surge
Onshore rush of water piled higher than normal as a result of high
winds on an open water bodys surface. It occurs primarily along the
open coast and can destroy houses, wash away protective dunes,
and erode soil.
Topographic quadrangle maps
A standard map size and scale used by the United States Geological
Survey (USGS) to show topography, roads, and landmarks.
Water mark
A mark, usually on structures, left by floodwaters.
Wind Water Line
An approximate boundary to delineate the inland extent of the area
where structures were damaged as a result of flooding from storm
surge from a particular event.  Landward of the line, most of the
damage is attributable to winds and/or wind-driven rain. Sometimes,
the Wind Water Line (WWL) is located along the debris line, but in
some cases, inundation and flood damage extend beyond the area
where major debris was deposited.
Wrack line
Defines the extent of flooding where organic-type debris such as
grass and weeds are carried by floodwaters and then dropped as
the floodwaters recede.
Background
Hurricane Katrina began as a tropical depression in the southeastern Bahamas on August
23, 2005. By the next day, the depression had developed into Tropical Storm Katrina.
Moving slowly northwesterly then westerly through the Bahamas, Katrina strengthened
over time. Just before landfall in South Florida on August 25, 2005, Tropical Storm
Katrina developed into a Category 1 hurricane, with wind speeds of 74 miles per hour
(mph)[reference footnote 1]  (64 knots[kts]) or greater. Landfall occurred around 6:30 p.m. eastern daylight time
(EDT) between Hallandale Beach and North Miami Beach, with wind speeds of
approximately 80 mph (70 kts). Gusts of 90 mph (78 kts) were measured as Katrina came
ashore. The storm moved southwesterly across the tip of the Florida peninsula with its
winds decreasing slightly (see Figure 1). However, having spent only 7 hours on land,
Katrina was not significantly diminished and regained intensity shortly after moving over
the warm waters of the Gulf of Mexico.
 Footnote 1 - Wind speed and central pressure data are from the National Climatic Data Center (NCDC).
Figure 1: Grapic depicion of Hurricane Katrina Storm Track
Source: http://cimss.ssec.wisc.edu/tropic/archive/2005/storms/katrina/katrina.html
Once over the Gulf of Mexico, Hurricane Katrina moved almost due west. A mid-level
ridge from Texas weakened and moved westward, causing Katrina to gradually move
northwest and then north over the next few days. Katrina attained major hurricane status
on the afternoon of the August 26, 2005, due to the atmospheric and sea level conditions
that rapidly intensified the storm.
Over the next 48 hours, Hurricane Katrina continued to intensify, moving in a northerly
direction. The storm reached maximum sustained wind speeds of 175 mph (152 kts) with
gusts of 215 mph (187 kts) on the morning of August 28, 2005, making it a Category 5
hurricane. Its minimum central pressure dropped that afternoon to 902 millibars (mb),
giving it the fourth lowest recorded central pressure for an Atlantic storm at the time and
the sixth lowest by the end of the 2005 hurricane season.  Later in the 2005 Hurricane Season, Hurricanes Rita and Wilma developed with minimum pressures of 897 mb and 882 mb, respectively. As a result, Katrina became the sixth most intense Atlantic Basin hurricane on record (Rita is now the fourth and Wilma ranks as the first).Tropical cyclones rarely stay at
Category 5 strength for long; Katrina weakened slightly to a Category 4, and then became
a Category 3 at its second landfall near Buras, Louisiana, on August 29, 2005, at
approximately 6:10 a.m. central daylight time (CDT) (see Figure 1). Maximum sustained
winds at landfall were approximately 127 mph (110 kts), making Hurricane Katrina a
Category 3 storm.
After crossing over Lake Borgne (located east of New Orleans) and the Mississippi Sound,
Katrina made its third landfall along the Louisiana/Mississippi border with wind speeds of
approximately 121 mph (105 kts). Gusts of over 90 mph (78 kts) were recorded in Biloxi,
Mississippi, while gusts reached approximately 80 mph (70 kts) in Mobile, Alabama.
Katrinas storm surge caused failure of the levee system that protects the City of New
Orleans, Louisiana, from Lake Pontchartrain and, subsequently, an estimated 80 percent of
the City was flooded. This and other major damage to the coastal regions of Alabama,
Louisiana, and Mississippi made Katrina the most destructive natural disaster in the history
of the United States.
Overview of Impacts in Louisiana
A disaster declaration in response to Hurricane Katrina was authorized by the President for
several parishes in Louisiana on August 29, 2005, with the Federal Emergency
Management Agency (FEMA) acting as the Federal Coordinating Agency (FEMA-1603-
DR-LA). In addition, several amendments were made to the initial declaration. The
declaration provided the necessary assistance to meet immediate needs and to help
Louisiana recover as quickly as possible through the following means:
Public Assistance (PA): includes supplemental Federal disaster grant assistance for
the repair, replacement, or restoration of disaster-damaged publicly owned
facilities, and the facilities of certain private non-profit (PNP) organizations. There
are seven subcategories (A-G) within this designation under two work types:
emergency work and permanent work. Unless otherwise noted, Public Assistance
will include all categories under both work types. However, often only the
emergency work categories are designated, which include Category A, debris
removal, and Category B, emergency protective measures.
Individual Assistance (IA): includes cash grants of up to $26,200 per individual or
household for housing (reimbursement for hotel or motel expenses, rental
assistance, home repair and replacement cash grants, and permanent housing
construction assistance in rare circumstances) and other needs (medical, dental, and
funeral costs, transportation costs, and other disaster-related needs).
Hazard Mitigation Grant Program (HMGP): may be used to fund projects that will
reduce or eliminate the losses from future disasters by providing a long-term
solution to a problem. Eligible applicants include state and local government,
Indian tribes or other authorized tribal organizations, and certain non-profit
organizations. FEMA can fund up to 75 percent of the eligible costs of each
project, and the state or grantee must provide a 25-percent match.
All Louisiana parishes were eligible for HMGP funds. Tables 1, 2, and 3 provide the
designations for FEMA-assistance eligibility by parish. In all, 31 parishes received IA
designations; 33 parishes received PA, Category B Only designations; 9 parishes were
eligible for PA, Category A and B Only; and 22 parishes were designated for PA, All
Categories. Note that all of the parishes designated for IA also received a PA designation
(either Categories A and B Only or All Categories). Figure 2 shows this same information
graphically.
Table 1: Parishes Designated for IA and PA
Ascension
Assumption
East Baton Rouge
Iberia
Iberville
Jefferson
Lafourche
Livingston
Orleans
Plaquemines
St. Bernard
St. Charles
St. Helena
St. James
St. John the Baptist
St. Martin
St. Mary
St. Tammany
Tangipahoa
Terrebonne
Washington
West Baton Rouge
Table 2: Parishes Designated for IA and PA 
Categories A and B Only
Acadia
Calcasieu
Cameron
East Feliciana
Jefferson Davis
Lafayette
Point Coupee
West Feliciana
Vermillion
Table 3: Parishes Designated for PA  Category B Only
Allen
Avoyelles
Beauregard
Bienville
Bossier
Caddo
Caldwell
Catahoula
Claiborne
Concordia
De Soto
East Carroll
Evangeline
Franklin
Grant
Jackson
La Salle
Lincoln
Madison
Morehouse
Natchitoches
Ouachita
Rapides
Red River
Richland
Sabine
St. Landry
Tensas
Union
Vernon
Webster
West Carroll
Winn
Figure 2: Map of all Louisiana parishes and designation of which are eligible for Individual and Public Assistance, Individual and Public Assistance (Category A and B) and Individual Assistance only for FEMA-1603-DR-LA Disaster Declaration
Levee Breaches
Hurricane Katrina passed just east of New Orleans shortly after 6:00 a.m. CDT on August
29, 2005. There were numerous breaches to the levee system as a result of Hurricane
Katrina that affected areas in Jefferson, Orleans, Plaquemines, and St. Bernard Parishes.
Figure 3 shows the location of the storm-induced breaches, as well as distressed areas and
deliberate levee breaches created to help drain waters after the flooding occurred. Pump
stations are also shown and are color coded based on their capacities in the days after
Hurricane Katrina. The major levee breaches are described in detail in the following
paragraphs. Levee breach approximate times and some details are taken from the Times-Picayune Flash Flood graphic published in print on May 14, 2006, and online at http://www.nola.com/katrina/graphics/flashflood.swf.
Before Hurricane Katrina made landfall, storm surge from Lake Borgne already began
pounding levees along the eastern edge of St. Bernard Parish. The parishs eastern levee
system began to be compromised at approximately 5:00 a.m. CDT, causing flooding of the
wetland area west of this levee system. Then, surge from Lake Borgne pushed westward
through the portion of the Intracoastal Waterway located between Eastern New Orleans
and St. Bernard Parish. The surge overtopped and breached levees along the canal
protecting eastern New Orleans. At approximately 8:30 a.m. CDT, the parishs western set
of levees protecting developed communities was compromised, and floodwaters poured
into these communities.
As Katrina made landfall at Buras shortly after 6:00 a.m. CDT, water from the Breton
Sound surged onto land overtopping the Mississippi River levees from the east side and
flooding Plaquemines Parish (south of area shown on Figure 3).
Water began to overtop flood walls and levees shortly before 7:00 a.m. CDT along the
Industrial Canal. Between 7:30 and 8:00 a.m. CDT, first the west side and then the east
side of the Industrial Canal was breached (see Figure 4). There were actually two breaches
on the east side of the Industrial Canal. Both of them were located to the north of the lock
separating the canal from the Mississippi River, between the Florida Avenue and Claiborne
Avenue Bridges.
Surge from Lake Pontchartrain also began straining the levee and floodwall system along
the London Avenue Canal. At approximately 9:00 a.m. CDT, walls on both sides of the
levee began showing signs of weakening. At approximately 9:30 a.m., the east side of the
canal began to fail north of the Mirabeau Avenue Bridge, followed by the west side at
approximately 10:30 a.m. CDT.  Also, at approximately 9:00 a.m. CDT, flooding occurred
east of the New Orleans Avenue Canal as water reached the foot of the canal and
overtopped the embankment.
Figure 3: Map showing New Orleans Area Levee Breaches
Source: U.S. Army Corps of Engineers
Figure 4: Photo of Southern Breach in the East Floodwall and Levee of the Industrial Canal
Source: http://homepage.ntlworld.com/c.mcmahon4/nola/industrial.htm
At approximately 9:45 a.m. CDT, the vital 17th Street Canal levee (see Figure 5) began to
be breached where it connects to the new hurricane proof Old Hammond Highway
Bridge. This breach sent water from Lake Pontchartrain coursing across Lakeview and into
Mid-City, Carrollton, Gentilly, City Park, and neighborhoods farther south and east. The
breach was an estimated 200 feet in length.
Figure 5: Photo of New Orleans 17th Street Canal at Old Hammond Highway Bridge
Source: http://en.wikinews.org/wiki/Image:New_Orleans_USACE-17th_Canal-A-09-04-05_0004.JPG
At least 80 percent of New Orleans was under water by August 31, 2005, as a result of the
levee failures (see Figure 6). The flooding also caused a water line main in New Orleans to
break, leaving the City without drinking water.
Figure 6: Photograph of Flooded Homes along New Orleans Levee
Source: http://homepage.ntlworld.com/c.mcmahon4/nola/london.htm
Reported Damage (Damage estimates are from an interview with FEMA Public Information Officer for Louisiana in mid-December 2005 and information provided by FEMA Jackson, Mississippi, Disaster Field Office personnel in January 2006.)
More than 1.7 million people lost power as a direct result of Hurricane Katrina. According
to the FEMA Public Information Officer for Louisiana, over 200,000 structures in
Louisiana were destroyed due to Hurricane Katrina. According to the Louisiana Economic
Development Office, an estimated 71,000 of those structures were businesses.
Infrastructure also suffered heavy losses; a preliminary estimate of $5.5 billion in damage
to infrastructure, including roads and bridges, was reported. Approximately 300,000 to
350,000 vehicles were destroyed, and approximately 2,400 ships and vessels were
wrecked. An estimated 46 million cubic yards of debris has been generated due to
hurricane damage. The number of people displaced is estimated to be 450,000, and
800,000 Louisiana citizens have requested assistance from various Federal and state relief
programs and agencies.
As of December 5, 2005, the Small Business Administration reported that requests for
$229 million in home and small business loans have been submitted. The insurance
industry has reported loss payouts in the amount of $20.8 million, while the National Flood
Insurance Program (NFIP) reported losses totaling $17 billion. As of December 3, 2005,
the Federal government had provided $3.6 billion in assistance to Louisiana. In January
2006, IA projections were at $7.7 billion, while the PA program had already allocated $1.2
billion.
Hurricane Katrina also caused major business disruptions. The financial impact on the
tourism industry is estimated to be approximately $11 billion. For the retail fishing
industry, losses are estimated at $1.29 billion, and for the recreational fishing industry a
loss of approximately $400 million was estimated.
The oil industry has estimated that 15 percent of the Gulf oil production was lost between
August 26 and November 10, 2005. Approximately 12 percent of natural gas production
along the Gulf Coast was lost during that same period.
Purpose
After a hurricane impacts a coastal area with significant flooding, it is imperative that data
be collected to document the event to assist in response, recovery, and mitigation efforts,
and to improve disaster preparedness and prevention efforts for future disasters. Wind
Water Line (WWL) data collection is an initial step in accurately documenting an event.
These data help place the event in historical perspective and improve the ability to estimate
current flood risk and future event prediction.
Collection of site-specific flood inundation data along rivers, bays, and coasts has
numerous applications. The purpose of this particular data collection effort was to
document the extent of flooding caused by storm surge that occurred as a result of
Hurricane Katrina in southeast Louisiana. There are several potential uses for these data,
including:
Estimating storm frequency and severity
Assessing accuracy of Flood Insurance Rate Maps (FIRMs)
Providing information for use with other studies, including FEMA Building
Performance Assessments
Assisting with the prioritization of mitigation projects and providing data for use in
benefit/cost analyses
Sharing information for calibrating models that simulate the storm (for example,
HAZUS and other coastal storm-surge models)
Helping to create flood recovery maps when coupled with sufficient data density
and observational information; building officials can use the maps to update
guidance for both reconstruction and future construction by local citizens,
developers, and contractors
Specific FEMA programs that directly benefit from post-disaster flood data collection
include:
IA Program  advises individuals on how to use Federal grants to increase their
homes flood resistance
PA Program  identifies appropriate flood mitigation measures to pursue when
providing Federal grants to repair infrastructure
HMGP  ensures that accurate benefit/cost analysis is performed
NFIP  provides insurance claim information, floodplain management, repetitive
loss classification, and flood hazard identification
The purpose of WWL data collection is to determine the inland extent of damages caused
by storm-surge-induced flooding, and differentiate this area from those areas farther inland
where damages were primarily the result of wind forces. By delineating the WWL, an
approximate boundary is created to distinguish areas where both storm-surge-induced
flooding and wind forces caused damage to structures from those areas where wind forces
were the primary cause of damages to structures, and storm-surge flooding did not have a
significant impact. Sometimes, the WWL is located along the debris line, but in some
cases, inundation and flood damages extend beyond the area where major debris was
deposited.
Overview of Related Projects
URS Group, Inc. (URS), with support from Government Services Integrated Process
Team, LLC, was tasked by FEMA under their existing Hazard Mitigation Technical
Assistance Program (HMTAP) contract to assist in disaster recovery efforts for Hurricane
Katrina. Assistance provided by this Task Order included data collection and visual survey
of the debris line and the extent of flooding to identify the WWL in the New Orleans area.
After Hurricane Katrina, FEMA issued several task orders under the HMTAP contract
called Rapid Response Task Orders. Generally, the purpose of these task orders is to allow
FEMA contractors to move quickly into disaster-stricken areas to collect perishable data
for use in defining the parameters of the event that can be used for future studies and flood
mitigation activities. In addition to the WWL Task Order, there were several other Rapid
Response Task Orders issued including Aerial Imagery Data Collection, Coastal High
Water Mark (CHWM) Surveys, and Riverine High Water Mark (RHWM) Surveys. HWM
Survey findings are used to define the extent of flooding, and therefore can be used in
conjunction with field findings from the WWL Task Order to determine the extent of the
WWL. Aerial imagery is also used to estimate the WWL; post-event imagery can be used
to identify areas affected by flood damages as well as the approximate inland extent of
storm surge flooding.
In response to Katrina, HMTAP Task Order 415, Rapid Response, Hurricane Katrina Wind
Water Line Data Collection  Louisiana was issued and is the focus of this report. In
addition, HMTAP Task Order 411, Rapid Response, Aerial Radar  Louisiana,
Mississippi, and Alabama; HMTAP Task Order 412, Rapid Response, Hurricane Katrina
Coastal High Water Mark Survey  Louisiana; and HMTAP Task Order 419, Rapid
Response, Hurricane Katrina Riverine High Water Mark Survey  Louisiana were also
issued. An overview of these task orders is provided below.
Under Task Order 411, Rapid Response, Aerial Radar  Louisiana, Mississippi, and
Alabama, cartographic analysts were tasked with using post-event aerial imagery to
delineate areas affected by flooding along the Louisiana Coast, with a focus on
New Orleans. Uses of post-event aerial imagery for Mississippi and Alabama are
discussed in the HMTAP task orders contracted for those states.
Through Task Order 412, Rapid Response, Hurricane Katrina Coastal High Water
Mark Survey  Louisiana, field crews collected perishable HWM data at field-
observed point locations. The crews looked for evidence of the peak elevation of
flooding caused by storm surge, then inventoried and surveyed these elevations.
Peak flood elevations in southeastern Louisiana were recorded at several locations
as part of this task order. These data can be used to help determine the extent of
flooding.
For Task Order 419, Rapid Response, Hurricane Katrina Riverine High Water
Mark Survey  Louisiana, field crews also collected HWM data at field-observed
point locations. Field crews for RHWMs focused on areas of overbank flooding
where heavy and/or prolonged precipitation resulted in an exceedance of the
capacity of rivers and streams to keep floodwaters within their banks. Peak flood
elevations for riverine-type flooding were surveyed and recorded as part of this task
order.
This report focuses on the results of data collected in Louisiana to determine the WWL.
Figure 7 shows the WWL Study Area within Louisiana; parishes included in the study area
are highlighted in yellow. The study area comprises parishes in southern coastal Louisiana,
including Jefferson, Lafourche, Orleans, Plaquemines, St. Bernard, and Terrebonne
Parishes. The study area also encompasses the parishes affected by the flooding of Lake
Pontchartrain and Lake Maurepas, including Ascension, Livingston, St. John the Baptist,
St. Tammany, and Tangipahoa Parishes, and two additional parishes along the Mississippi
River, St. Charles and St. James Parishes.
Figure 7: Map of WWL Study Area within Louisiana
Methodology
There were two basic elements to this project: field data collection and WWL mapping.
While field crews worked to collect data in the weeks following Hurricane Katrina, the
WWL mapping process occurred after the data had been collected and involved
interpretation and analysis of data from several sources.
Data Collection Methodology
URS field crews collected WWL data for Hurricane Katrina in Louisiana. The teams met
in Baton Rouge, Louisiana, on September 8, 2005, to be briefed on the project and form
field crews. On September 9, 2005, field data collection began. However, access to the
New Orleans area was restricted because floodwaters still covered much of the City.
Efforts were initially focused on areas outside of the City. By September 14, 2005, field
crews began to gain access to New Orleans, and data collection within the City was
underway.
Data collection for Task Order 415, Rapid Response, Hurricane Katrina Wind Water Line
Data Collection  Louisiana was performed in conjunction with data collection for Task
Order 412, Rapid Response, Hurricane Katrina Coastal High Water Mark Survey 
Louisiana and Task Order 419, Rapid Response, Hurricane Katrina Riverine High Water
Mark Survey  Louisiana. Under Task Orders 412 and 419, field crews collected
perishable HWM data at field-observed, point locations. Under Task Order 412, they
looked for evidence of the peak elevation of flooding caused by storm surge, then
inventoried and surveyed these elevations. CHWM points are taken where surge directly
affects flood levels, including the shoreline of open coasts, bays, and tidally influenced
rivers. CHWMs are formed when the water level during a storm rises to a maximum
elevation and leaves marks on the interior and/or exterior walls of a structure, or debris or
wrack lines along the ground. CHWM field crews are responsible for identifying these
marks and recording basic information about the data point. Survey crews then use these
initial records to later relocate the points and survey them to determine the peak elevation
of flooding.
The WWL points, which are also located by identifying water marks on structures or
debris or wrack lines, doubled as HWMs. WWL points are used to define the inland extent
of damage to structures caused by surge flooding. Thus, the points generally form a line
showing the approximate inland limit of surge flooding. The WWL is so called because
landward of the line in coastal areas, damage to structures is usually limited to wind
damage, which includes direct rain damage, where the envelope of the structure may have
been compromised. Seaward of the line, damage to structures is the result of surge-induced
flooding with wind forces contributing as well (see Figure 8).
URS field crews were tasked with identifying data points for a WWL for southeast
Louisiana with a focus along the open coasts of the Gulf of Mexico, the shores of Lake
Pontchartrain, and areas affected by the breached levees. Parish emergency managers were
contacted prior to field work within each parish to inform them of the crews work and site
investigations and to acquire any available information about the location and extent of
damages to structures within the parish. Priority was given to areas of known damage to
structures and significant flooding as identified by parish emergency managers.
The presence of low swampy ground made determination of the limit of the coastal storm
surge difficult to establish along coastlines (i.e., southern areas in Lafourche, Plaquemines,
and Terrebonne Parishes and eastern St. Bernard Parish), inland swamps/marshes (i.e.,
Lake Maurepas area and the southern portion of Tangipahoa Parish), and up river courses
affected by surge. Where access was available and a determination as to the approximate
location of the WWL was possible, data points were taken. Ideally, these points were taken
every 2 to 4 miles along coastlines and at denser intervals in more populated areas,
including the City of New Orleans. Field crews data were sent to a central processing unit
in a local URS office each night and data points were plotted to ensure adequate spatial
coverage. Figure 9 shows the WWL data point distribution, which illustrates the overall
coverage of WWL points and highlights areas where there was a lack of data points due to
swampy or marshy land areas or inaccessibility.
Figure 8: Graphic - WWL Illustration (Profile View/Plan View)
The area highlighted by a pale blue-green overlay on Figure 9 shows coastal
swamps/marshes (developed from ESRI open water coverage) where access was limited
and the WWL points were difficult to find. The hatched green area by Lake Maurepas
shows one of the larger inland wetland areas where the land use/vegetation and lack of
roads prevented access and WWL points were difficult to distinguish.
Each field team was tasked with identifying the WWL and collecting data points. The
WWL was located by observing wrack lines, debris lines, or by locating water marks close
to the ground and tracing them along topographic features to determine the extent of
flooding. Generally, when these features were observed within 1.5 feet of the ground and
the field crews could validate through field observations or interviews with local citizens
that these features were near the edge of inundation, these points were marked as WWL
data points.
Figure 9: Map depicting WWL Data Point Distribution
Data collection had to be completed quickly given the perishable nature of the data; as
community cleanup efforts progressed, valuable debris line (see Figure 10) and HWM (see
Figure 11) data were being destroyed. The field crews collected raw data for both WWLs
and HWMs from September 9 through September 19, 2005. The data for each data point
were stored in a database (see Appendix A). In fact, as previously mentioned, the WWL
points doubled as HWM points since a flood elevation could be determined at each of the
WWL data points. Therefore, the WWL data points are actually a subset of the HWM data
points. WWL data points are assigned a HWM identification number that is also used as
their WWL identifier. It is a three-part alphanumeric label. For example, a point might be
labeled KLAC-05-16. The leading K indicates that the HWM/WWL data point is a
Hurricane Katrina data point, the middle LA stands for Louisiana, and the last letter can
be either a C or an R indicating coastal or riverine flooding. The middle two-digit
number identifies the field crew that gathered the data, and the final two-digit number
identifies the sequential data points collected by the field crew.
At each observed WWL point, the following data were collected:
Address (if the point was near an addressable structure)
Latitude/longitude reading, taken in North American Datum of 1983 (NAD83),
which is used as the standard map coordinate system default by the majority of
Global Positioning System (GPS) devices
Location description (e.g., neighborhood or other descriptive name)
Date data point was taken
Type of data point, including debris line, water mark, wrack line (indicates the high
tide mark), etc.
Type and severity of observed wind damage
Flood source
Approximate flood depth (if a water mark data point)
Digital photographs (named according to the WWL point identification number;
see Appendix B). The SD memory cards containing some of the images became corrupt, and, as such, the images on them were unrecoverable. For this reason, images for 10 of the WWL points are not available.
Figure 10: Photo  - Example of a Debris Line
Figure 11: Photo - Example of an HWM
Mapping Methodology
To create the WWL maps, the project team relied heavily on data supplied from both
HMTAP Task Order 411, Rapid Response, Aerial Radar  Louisiana, Mississippi, and
Alabama, and HMTAP Task Order 412, Rapid Response, Hurricane Katrina Coastal High
Water Mark Survey  Louisiana.
Under Task Order 411, Rapid Response, Aerial Radar  Louisiana, Mississippi, and
Alabama, cartographic analysts used post-event aerial imagery to delineate areas affected
by flooding along the Louisiana coast, with a focus on New Orleans. The analysts used
natural color orthorectified imagery acquired between September 4 and September 17,
2005, by the firm 3001, Inc. The analysts studied the imagery to locate the extent to which
high-velocity floodwaters, including coastal surge, pushed debris inland, and to delineate
areas beyond these debris lines where floodwaters had continued to push inland causing
additional flood inundation without leaving behind major debris. Contour data were
created using U.S. Geological Survey (USGS) Digital Elevation Models (DEMs) to
perform checks as needed of the analysts interpretations against elevation data. A
Geographic Information System (GIS) coverage showing the approximate extent of
flooding was created as part of this task order. Appendix C includes a summary report
prepared by the cartographic analysts summarizing their methodology and product.
Under this task order, Task Order 415 Rapid Response, Hurricane Katrina Wind Water
Line Data Collection  Louisiana, field WWL data points were used together with the
information about the extent of flooding determined as part of the aerial imagery task order
(Task Order 411, Rapid Response, Aerial Radar  Louisiana, Mississippi, and Alabama) to
finalize the aerial measure of inundation based on both photointerpretation and field
ground-truthed data. The inundation areas defined under Task Order 411, Rapid Response,
Aerial Radar  Louisiana, Mississippi, and Alabama, served as the base data for
determining the WWL, and the field data collected under this Task Order 415 Rapid
Response, Hurricane Katrina Wind Water Line Data Collection  Louisiana were
compared to this base data to determine if the two data sets were in agreement. A
geodatabase with the WWL data points was created. Where WWL field data point
locations varied from the photointerpreted flood area delineation by more than 200 feet,
analyses using information about the depth of flooding and flood elevation for the WWL
(and potentially for nearby HWM points) were conducted. If the flood elevation data and
supporting documentation, including comments and photographs from the field crews,
confirmed that the WWL point was correct, the inundation coverage was modified to agree
with the field-collected data, and topography (note reference 6) was used to delineate the boundaries for
these modifications. Notes from these comparisons are included in tabular format in
Appendix D.
Reference 6 - Topography was obtained from the Louisiana State University website at http://atlas.lsu.edu/. It is 2-foot contour data provided to the University by the Louisiana Oil Spill Coordinators Office and was generated from Light Detection and Ranging (LiDAR) data processed by 3001, Inc. The elevation data were developed in five phases between 2000 and 2003. Error measurements for the data were derived by surveying elevations at check points and comparing them to the LiDAR-developed elevation data. This comparison showed that the mean elevation difference for all points ranged from -6.41 centimeters (phases 3 and 4) to 0.64 centimeters (phase 5). The greatest Vertical Root Mean Square Error reported was 11.65 centimeters (phase 1).
The extent of flooding was defined not only by the WWL points, but also from data
collected as part of the HWM Surveys (Task Orders 412 and 419). In some areas, it was
difficult to locate WWL points, either because areas could not be accessed by field crews
(no roads, undeveloped areas, etc.) or because there was no clear physical evidence to
define a WWL point. This happened particularly in swampy/marshy areas where it was not
clear how far inland the surge had moved through the swamps and marshes. In these cases,
the elevation data from the HWM surveys were used to complement the data. The HWM is
a measure of the peak flood elevation and, when used along with reliable topography data,
can help to determine an approximate WWL boundary. In these cases, HWM points that
appear to be near the edge of inundation (based on interpolation from other WWL points or
boundary estimates) should be used, as surge-induced flood elevations will generally
increase towards the coastline. Information about these HWMs and how they were used is
provided in Table 4, and an overview map of their locations is shown in Figure 12.
Table 4. HWMs Used to Help Delineate the WWL
CHWM ID:KLAC-02-06
ELEVATION (feet NAVD 88a):3.1
LOCATION:West of Lake Maurepas
ISSUE:Only one WWL point in this area and post-event imagery ends approximately 10,000 feet west of Lake Maurepas, so there were no photointerpreted inundation boundaries here either.
ACTION:Elevation of 4 feet was used as a guide in this area to estimate the extent of
flooding.
CHWM ID:KLAC 02-07
ELEVATION (feet NAVD 88a):2.8
LOCATION:West of Lake Maurepas
ISSUE:Only one WWL point in this area and post-event imagery ends approximately 10,000 feet west of Lake Maurepas, so there were no photointerpreted inundation boundaries here either.
ACTION:Elevation of 4 feet was used as a guide in this area to estimate the extent of
flooding.
CHWM ID:KLAC 02-08
ELEVATION (feet NAVD 88a):3.3
LOCATION:West of Lake Maurepas
ISSUE:Only one WWL point in this area and post-event imagery ends approximately 10,000 feet west of Lake Maurepas, so there were no photointerpreted inundation boundaries here either.
ACTION:Elevation of 4 feet was used as a guide in this area to estimate the extent of
flooding.
CHWM ID:KLAC 02-09 (note reference b)
ELEVATION (feet NAVD 88a):5.4
LOCATION:West of Lake Maurepas
ISSUE:Only one WWL point in this area and post-event imagery ends approximately 10,000 feet west of Lake Maurepas, so there were no photointerpreted inundation boundaries here either.
ACTION:Elevation of 4 feet was used as a guide in this area to estimate the extent of
flooding.
CHWM ID:KLAC 07-01
ELEVATION (feet NAVD 88a):4.0
LOCATION:West of Lake Maurepas
ISSUE:Only one WWL point in this area and post-event imagery ends approximately 10,000 feet west of Lake Maurepas, so there were no photointerpreted inundation boundaries here either.
ACTION:Elevation of 4 feet was used as a guide in this area to estimate the extent of
flooding.
Reference a - NAVD 88 = North American Vertical Datum of 1988
Reference b  - A WWL point, but the surveyed elevation was used to help determine the extent of flooding in surrounding areas.
Figure 12. Map depicting location of HWMs Used to Help Delineate the WWL
The complicated flooding patterns that occurred within the City of New Orleans due to the
levee breaches made the field identification of WWL data points more challenging. Some
CHWMs were determined to actually be WWL data points when data were reviewed after
crews returned from the field. These data points are presented in Table 5.
Table 5. HWM Data Points Used as WWL Data Points
CHWM ID:KLAC 06-28
LOCATION:New Orleans, along Lake Pontchartrain
REASONING:Aerial imagery indicated that this was the boundary of flooding, and
field crew personnel noted that, along Lake Pontchartrain by the levee
east of the Lakefront Airport, there was some dry ground as land
sloped upward.
CHWM ID:KLAC 06-29
LOCATION:New Orleans, along Lake Pontchartrain
REASONING:Aerial imagery indicated that this was the boundary of flooding, and
field crew personnel noted that, along Lake Pontchartrain by the levee
east of the Lakefront Airport, there was some dry ground as land
sloped upward.
CHWM ID:KLAC 06-30
LOCATION:New Orleans, along Lake Pontchartrain
REASONING:Aerial imagery indicated that this was the boundary of flooding, and
field crew personnel noted that, along Lake Pontchartrain by the levee
east of the Lakefront Airport, there was some dry ground as land
sloped upward.
CHWM ID:KLAC 06-31
LOCATION:New Orleans, along Lake Pontchartrain
REASONING:Aerial imagery indicated that this was the boundary of flooding, and
field crew personnel noted that, along Lake Pontchartrain by the levee
east of the Lakefront Airport, there was some dry ground as land
sloped upward.
CHWM ID:KLAC 07-47
LOCATION:New Orleans, north of Mississippi River west of confluence with Industrial
Canal
REASONING:Aerial imagery indicated that this was the boundary of flooding, and
field crew personnel noted that on the western side of the Industrial
Canal, in New Orleans east, there was a dry area. St. Claude Avenue
seemed to be the WWL line. On the east side of the Industrial Canal,
the water got closer to the levee.
CHWM ID:KLAC 07-48
LOCATION:New Orleans, north of Mississippi River west of confluence with Industrial
Canal
REASONING:Aerial imagery indicated that this was the boundary of flooding, and
field crew personnel noted that on the western side of the Industrial
Canal, in New Orleans east, there was a dry area. St. Claude Avenue
seemed to be the WWL line. On the east side of the Industrial Canal,
the water got closer to the levee.
The GIS maps also show a general coastal wetland coverage based on National Wetlands
Inventory (NWI) data to illustrate why WWL data points could not be located along much
of the southern coast of southeast Louisiana.
HWMs were used to determine the inland limit of surge along coastal rivers. Because
HWMs are grouped into two types, coastal and riverine, they serve as a good tool to help
distinguish these two types of flooding.  Therefore, the first general indication of the extent
of surge was the boundary between CHWMs and RHWMs along a given watercourse.
After finding this boundary area, surge elevations for the closest CHWMs were identified,
and the inland limit of surge was mapped by following the topography along these
elevations.
In Louisiana, this method was used along the Pearl River and the Mississippi River. Along
the Pearl River, two CHWMs were used to make the determination. However, one point
was located in Louisiana, and the other was across the state line along the river in
Mississippi. KLAC 06-05, the point in Louisiana, was located approximately 18.5 miles
inland of the rivers mouth at Lake Borgne and the Mississippi Sound. The other point,
which was in Mississippi, was named KMS USGS-105 and located about 14 miles inland.
As shown in Table 6, using these two points, an elevation of 15 feet NAVD 88 was
determined to be the maximum elevation along the river where surge effects occurred.
Table 6. CHWM Points Used to Determine the Inland Extent of Surge Flooding along
the Pearl River
POINT:KLAC 06-05
DISTANCE INLAND FROM RIVER MOUTH (linear miles):18.5
ELEVATION (feet NAVD 88):15.2
ELEVATION USED (feet NAVD 88):15
POINT:KMS-USGS-105 (reference a)
DISTANCE INLAND FROM RIVER MOUTH (linear miles):13.8
ELEVATION (feet NAVD 88):14.8
ELEVATION USED (feet NAVD 88):15
Reference a - Some HWM points from USGS field teams were also available.
Along the Mississippi River, two points were used, KLAC 02-04 and KLAC 06-10, that
are located well inland in western Jefferson Parish. These points provided the surge
elevation used to determine the extent of the WWL along the river. This elevation was
determined to be 18 feet NAVD 88 as shown in Table 7.
Table 7. CHWM Points Used to Determine the Inland Extent of Surge Flooding along
the Mississippi River
POINT:KLAC 02-04
ELEVATION (ft NAVD 88):17.8
ELEVATION USED (ft NAVD 88):18
POINT:KLAC 06-10
ELEVATION (ft NAVD 88):17.9
ELEVATION USED (ft NAVD 88):18
GIS maps of the WWL were produced at a scale of 1:24,000 (see Appendix E). The maps
depict the location of each WWL data point and the WWL. Additionally, they show the
debris line and inundation located inland of the debris line. The GIS maps are based on
USGS 7.5-minute topographic quadrangle maps.
Recommendations
The use of post-event imagery analyzed through photointerpretation, combined with field
data and observations, allowed for a balanced interpretation of the WWL and extent of
flooding, as shown on the maps in Appendix E. The post-event imagery provided an
overview of the extent of flooding within the area and a basis for determining the general
flood boundaries. The field data, including field crews damage observations, pictures,
notes about flood depths, etc., provided true ground observations to compare to the WWL
developed through the use of the debris line and flood extent created via
photointerpretation of the post-event imagery.
One potential area for improvement in the field data collection methodology would be the
use of teams with a more specific focus on WWL data collection. While HWM data and
field crew observations were helpful in interpreting the WWL locations, field crews with a
more narrow focus aimed solely at determining the WWL would probably have allowed
for more specific and/or descriptive data about WWL indicators and damages at sites, as
well as better visual documentation (photographs) illustrating evidence of the WWL.
Much of southeastern Louisiana consists of swampy wetlands, which presented a major
impediment to field data collection and prevented access to coastal areas in several of the
affected parishes. While development in these areas is limited (along with the potential for
damage), being able to collect data here would have allowed for a more continuous WWL
to be delineated along the entire coastline. One possible solution would be to perform a
flyover by renting time on a helicopter or small plane to observe conditions along these
swampy coastal areas that would help to define the WWL.
Also, a better log or record of field crews attempts to access areas where no data points
were identified would help to create a clearer picture of the efforts made and the ground
covered when there are no WWL data points to illustrate the crews findings. One possible
solution would be to make better use of mapping/navigational software to record crews
movements each day. Crews can note directly on a map what hindrances or problems kept
them from collecting data in specific areas.
Findings and Observations
The WWL is shown as the inland extent of coastal flooding on the maps in Appendix E.
Many of the WWL data points were taken around Lake Ponchartrain where there is the
highest concentration of development in the affected area, which includes the City of New
Orleans. Table 8 shows locations affected by flooding, their corresponding flood sources,
and the map sheet names and numbers contained in Appendix E.
Table 8. Summary of Flood Sources and Map Sheets by Parish
PARISH:Ascension
LOCATION (City or Area):Eastern portion of parish
MAJOR FLOOD SOURCES:Lake Maurepas and surrounding swamps and rivers, including the Petit Amite and Amite Rivers
MAP SHEET NAMES AND NUMBERS:French Settlement  7, Mount Airy NW  18, Sorrento 17
PARISH:Jefferson
LOCATION (City or Area):Coast along Lake Pontchartrain
MAJOR FLOOD SOURCES:Lake Pontchartrain and canal system
MAP SHEET NAMES AND NUMBERS:Indian Beach  28, La Branche  27, Luling  33, New Orleans East  35, New Orleans West  34
PARISH:Jefferson
LOCATION (City or Area):Central portion of parish
MAJOR FLOOD SOURCES:Intercoastal Waterway, Lake Cataouatche, and Lake Salvador
MAP SHEET NAMES AND NUMBERS:Barataria  44, Bertandville  40, Lafitte  45, Lake Cataouatche East  39
PARISH:Lafourche
LOCATION (City or Area):Central eastern border of parish at Lake Salvador
MAJOR FLOOD SOURCES:Lake Salvador
MAP SHEET NAMES AND NUMBERS:Barataria  44, Catahoula Bay  43, Des Allemands  37
PARISH:Lafourche
LOCATION (City or Area):Gulf Coast
MAJOR FLOOD SOURCES:Gulf of Mexico
MAP SHEET NAMES AND NUMBERS:No sheets printed for Gulf Coast area
PARISH:Livingston
LOCATION (City or Area):Southern portion of parish
MAJOR FLOOD SOURCES:Lake Maurepas, Amite River, Blind River, Natalbany River, Petit Amite River, and Tickfaw
River
MAP SHEET NAMES AND NUMBERS:French Settlement  7, Killian  9,  Mount Airy NE  19, Mount Airy NW  18, Springfield  2, Whitehall  8
PARISH:Orleans
LOCATION (City or Area):City of New Orleans
MAJOR FLOOD SOURCES:Lake Pontchartrain and canal system including Industrial Canal, London Avenue Canal, and 17th Street Canal
MAP SHEET NAMES AND NUMBERS:Chalmette  36, Chef Menteur  31, Little Woods  30, New Orleans East  35, North Shore  21, Rigolets  22, Spanish Fort  29
PARISH:Plaquemines
LOCATION (City or Area):Gulf Coast
MAJOR FLOOD SOURCES:Gulf of Mexico
MAP SHEET NAMES AND NUMBERS:No sheets printed for Gulf Coast area
PARISH:Plaquemines
LOCATION (City or Area):Along Mississippi River
MAJOR FLOOD SOURCES:Mississippi River
MAP SHEET NAMES AND NUMBERS:Belle Chasse  41, Bertandville  40, Buras  52, Chalmette  36, Empire  51, Happy Jack  49
Lafitte  45, Lake Laurier  47, New Orleans East  35, Phoenix  46, Pilottown  55,
Point a la Hache  48 , Port Sulphur  50, Triumph  53, Venice  54
PARISH:St. Bernard
LOCATION (City or Area):Western portion of parish
MAJOR FLOOD SOURCES:Industrial Canal, Intercoastal Waterway, and Lake Borgne
MAP SHEET NAMES AND NUMBERS:Belle Chasse  41, Chalmette  36, Delacroix  42
PARISH:St. Charles
LOCATION (City or Area):Entire parish
MAJOR FLOOD SOURCES:Lake Pontchartrain, Lake Salvador, Lake Cataouatche, and the Mississippi River
MAP SHEET NAMES AND NUMBERS:Barataria  44, Catahoula Bay  43, Des Allemands  37, Hahnville  32, Lake Cataouatche East  39, Lake Cataouatche West  38,  Laplace  26, La Branche  27, Luling  33
PARISH:St. James
LOCATION (City or Area):Northeast corner of parish
MAJOR FLOOD SOURCES:Lake Maurepas and the Mississippi River
MAP SHEET NAMES AND NUMBERS:Convent  23, Lutcher  24, Mount Airy NW  18, Sorrento  17
PARISH:St. John the Baptist
LOCATION (City or Area):Parish coastline along Lake Pontchartrain and Mississippi River
MAJOR FLOOD SOURCES:Lake Maurepas, Lake Pontchartrain, Mississippi River, and Pass Manchac
MAP SHEET NAMES AND NUMBERS:Laplace  26, Lutcher  24, Manchac  10, Mount Airy NE  19, Mount Airy NW  18, Ponchatoula SE  11, Reserve  25, Ruddock  20
PARISH:St. Tammany
LOCATION (City or Area):Southern parish along Lake Pontchartrain and eastern parish bordering Lake Borgne and the Pearl River (reference 1)
MAJOR FLOOD SOURCES:Lake Borgne, Lake Pontchartrain, Pearl River, and West Pearl River
MAP SHEET NAMES AND NUMBERS:Covington  4, Covington SW  12, Haaswood  16, Hickory  5, Madisonville  3, Mandeville  13, Nicholson  6, North Shore  21, Lacombe  14, Rigolets  22, Slidell  15
PARISH:Tangipahoa
LOCATION (City or Area):Southern parish along Lake Pontchartrain
MAJOR FLOOD SOURCES:Lake Maurepas, Lake Ponchartrain, Natalbany River, Pass Manchac and Tangipahoa River
MAP SHEET NAMES AND NUMBERS:Manchac  10, Ponchatoula SE  11, Springfield  2
PARISH:Terrebonne
LOCATION (City or Area):Gulf Coast
MAJOR FLOOD SOURCES:Gulf of Mexico
MAP SHEET NAMES AND NUMBERS:No sheets printed for this parish
Reference 1:Most of eastern coast is not shown on maps. Focus is on surge flooding along coastlines of lakes.
Following is a brief summary of the extent of surge-related flooding in each of the parishes
included as part of the study. It is suggested that the reader view the maps included in
Appendix E while reading these summaries.
Ascension Parish
In Ascension Parish, flooding occurred in the eastern portion of the parish in an area that is
mapped as a swamp/marsh. The WWL is located an estimated 3 to 3.5 miles inside of
Ascension Parish from its eastern border with St. John the Baptist Parish, westward to near
State Highway 22 on the north side and to U.S. Highway 61 on the south side (see map
sheets 7, 17, and 18). The WWL in this area was developed based on HWMs and
topography. Aerial imagery was not available, and WWL data points were not taken
because of the swampy nature of the area.
Jefferson Parish
Flooding in Jefferson Parish is attributed to the canal and pumping system being
overwhelmed (see map sheets 27, 28, 33, 34, and 35). Unlike Orleans and St. Bernard
Parishes, flood water was pumped out relatively quickly. Aerial imagery did not show
clear signs of flooding in this area; however, field data collection for both WWL data
points and CHWM data points showed that flood elevations were approximately -4 feet
(NAVD 88) for much of the parish near Lake Pontchartrain; much of the parish lies below
0 feet (NAVD 88).
In the central and southern portions of the parish, some flooding occurred along the eastern
edges of Lake Cataouatche and Lake Salvador. This flooding is shown on map sheets 39
and 44. The central portion of the parish is also shown on map sheets 40 and 45.
Lafourche Parish
In Lafourche Parish, the WWL was not delineated along the Gulf Coast. No field data
points were collected for this parish, and post-event imagery did not include this area.
WWL data points were not taken in most of this parish because surge effects occurred only
in the undeveloped, largely inaccessible swampy areas along the southern coast. The
wetlands coverage shown on the Appendix E map sheets (see map sheets 37, 43, and 44)
shows the extent of NWI wetland areas where surge effects were difficult to identify.
Along the eastern border of the parish, a WWL is shown along Lake Salvador (see map
sheets 43 and 44) and extends from 150 feet landward of the lake in some areas to as much
as approximately 3,000 feet landward.
Livingston Parish
The WWL is located north and west of Lake Maurepas, as much as 2 miles inland in some
areas (see map sheets 2, 7, 8, 9, 18, and 19). State Highway 22 borders the low wetland
areas near Lake Maurepas, and the WWL follows the roadway for much of the length of
the parish.
Orleans Parish
The WWL in Orleans Parish is complicated; all three of the major levee breaches
associated with Hurricane Katrina occurred in this parish in the New Orleans area (see map
sheets 29 and 35). The New Orleans Uptown Area, Garden District, and most of the
French Quarter were spared from major flooding, but most of the rest of the City was
flooded, as evidenced by the WWL. The WWL extends inland from the Lake Pontchartrain
coast about 3.5 to 7.5 miles (see map sheets 29, 30, 35, and 36). However, much of the
Lakeshore area just behind the lakes levees west of the Industrial Canal was spared. The
portion of the parish south of the Mississippi River was also spared from flooding (see map
sheets 34 and 35). East of the Industrial Canal (see map sheets 35 and 36), most areas were
affected by flooding, but there are some pockets of high ground here, including areas along
Gentilly Road and areas just behind the lakes levees.
Plaquemines Parish
Most development in Plaquemines Parish is located along the Mississippi River where
there is a system of levees. Beyond the river, most of the parish consists of low, wetland
areas. The levees were overtopped during Katrina, and developed areas along the levees
were flooded. The east bank was hit particularly hard, and several communities in the
parish sustained severe damage (see map sheets 40, 41, and 45-56). The WWL shows
where flooding occurred just outside of the levees. Wetland areas are shown as such,
indicating that surge effects occurred in these areas along the eastern and southern coasts.
St. Bernard Parish
There is considerable information that surge flooding occurred in St. Bernard Parish from
Lake Borgne. The extent of wetlands in the parish, particularly in its eastern portion, made
delineation of a WWL difficult (see Figure 3 and the pre-Katrina wetlands in St. Bernard
Parish). Field crews could not gain access to this wetland area to obtain data points, nor
could imagery analysts identify flooded wetlands. Therefore, although the WWL does not
show flooding in this area (eastern part of panel 36 and points eastward), the NWI
wetlands coverage is included to highlight this and other wetland areas where constant
wet conditions persist.
Field crews and imagery analysts were able to collect and assess data for western St.
Bernard Parish (see map sheets 36, 41, and 42). However, its important to note that the
eastern border of the WWL in this area ends at one of the parishs levee systems, which is
also the border of the NWI wetlands. According to recent reports, however, the surge
affecting even this western portion of the parish came largely from Lake Borgne and
breached this levee system. Therefore, although the eastern area is shown as wetlands,
surge from Lake Borgne did travel through this area, reached the western portion of the
parish via levee breaches, and caused flooding.
St. Charles Parish
In St. Charles Parish, the WWL along Lake Pontchartrain extends inland for approximately
3 to 5 miles, with U.S. Highway 61 forming the border for most of the WWL. Flooding
along the Mississippi was contained within the levees in this parish (see map sheets 26, 32,
and 33). Further south along Lake Salvador and Lake Cataouatche, some relatively minor
flooding resulted in a WWL around and between the lakes (see map sheets 38 and 39).
Generally, this WWL stays within 500-1,500 feet of the lakes coastlines in wetland areas.
St. James Parish
St. James Parishs northeast corner was affected by flooding from Lake Maurepas;
however, this area consists primarily of wetlands. Areas south and west of U.S. Highway
61, where development begins, are beyond the WWL. Flooding along the Mississippi
River was contained within the levee system.
St. John the Baptist Parish
Much of the parish north of I-10 is composed of swamp/marsh areas and portions of lakes
Pontchartrain and Maurepas. Between I-10 and U.S. Highway 61, most areas were
inundated with flooding from Lake Pontchartrain (see map sheets 25 and 26). This area
includes the cities of Garyville, Reserve, and Laplace. However, developed areas south of
I-10 and between State Highway 3188 and Highway 51 (a portion of the City of Laplace)
were an exception and were not inundated. In this parish, flooding along the Mississippi
River was contained within the levee system (see map sheets 17, 18, 23, and 24).
St. Tammany Parish
Along Lake Pontchartrain, the WWL is located from approximately 3,000 feet inland of
the shore (west of Lacombe Bayou and south of U.S. Highway 190 as shown on map
sheets 3, 4, 12, 13, and 14) to as much as 4 miles inland along Lacombe Bayou (see map
sheet 14). East of Lake Pontchartrain at the Pearl Rivers confluence with Lake Borgne, a
debris line is shown approximately 3.5 to 5.5 miles inland (see map sheets 21 and 22).
Tangipahoa Parish
WWL data points were not taken in this area, so the WWL is based on data from HWMs
and aerial imagery. The WWL ended in swampy, undeveloped areas that make up the
southern portion of the parish (see map sheets 2, 10, and 11).
Terrebonne Parish
In Terrebonne Parish (as in Lafourche Parish), a WWL was not drawn because only one
field data point was collected and imagery did not include this area. WWL data points were
not taken in most of this parish because surge effects occurred only in the undeveloped,
largely inaccessible swamp/marsh areas along the southern coast. The NWI wetlands
coverage shown on the Appendix E index sheet indicates areas where surge effects were
difficult to determine given the land cover.
Conclusion
Although field crews attempted to visit coastal areas along the Gulf of Mexico in
Terrebonne, Lafourche, Plaquemines, and St. Bernard Parishes, the swampy characteristics
of the Louisiana coast prevented access to and clear identification of WWL points in many
of these areas. However, coverage was developed to show these swamp/marsh areas by
using information such as the land cover shown in aerial imagery (post-event imagery
obtained under HMTAP Task Order 411) and other sources of GIS land and water cover
data, including NWI data. Effects from surge in these areas were partially absorbed by the
swamps, but the swamps did not fully buffer the effects of the storm, particularly in
Plaquemines and St. Bernard Parishes where there was extensive damage farther inland.
Similarly, low-lying swamp/marsh areas west of Lake Pontchartrain near Lake Maurepas
were difficult to access, and thus estimates of the WWL in these areas are based on
elevations of CHWMs and topography. The WWL in this area extends several miles west
of Lake Maurepas where swamp/marsh areas can be found. Field crews noted that much of
this area lacks significant development due to the land cover.
A total of 45 WWL data points were identified in southeast Louisiana by the field crews.
Of these, 23 data points were located in Orleans Parish, 6 were in Jefferson Parish, 5 were
in both St. Tammany and St. Charles Parishes, 2 were in Plaquemines Parish, and 1 data
point each was in the remaining parishes of Livingston, St. James, Terrebonne, and St.
John the Baptist.
Of these 45 points, 11 were within a range of approximately 200 feet from either the debris
line or inundation polygon developed by photointerpretation of the post-event imagery.
Using the remaining 34 points, including the field crews observations, photographs, post-
event imagery, local topography, and base mapping, engineers analyzed the
photointerpreted debris line and inundation area and decided that 18 of these points would
be used to actually edit the photointerpreted data.
Appendix A: WWL Data Points
Appendix A contains a table with field-collected data for each WWL data point. These
data are first referenced in the Data Collection Methodology section of this report and were
collected between September 9 and September 22, 2005. As described in the Mapping
Methodology section, the data points were used together with the information about the
debris line and the extent of flooding determined through photointerpretation of post-event
imagery to delineate the WWL as presented on the maps in Appendix E. A description of
how the data points were used to edit the debris line and limits of inundation defined
through photointerpretation of the imagery can be found in Appendix D.
APPENDIX A IS NOT INCLUDED IN THE REPORT VERSION FOR PUBLIC RELEASE
DUE TO PRIVACY ISSUES.
Appendix B: WWL Photographs
Appendix B contains an index and thumbnails of the photographs that correspond to each
WWL data point presented in Appendix A. The naming convention for the photographs
uses the data point ID Number (KLAC-XX-XX) and then a sequential number for the
photographs(s) associated with that ID Number (KLAC-XX-XX-1, KLAC-XX-XX-2). In
most instances, two photographs were taken for each data point; however, when additional
information was needed, three photographs were taken.
NOTE: The SD memory cards containing some of the images became corrupt and the
images on them were unrecoverable. For this reason, images for some of the data points
are not available.
APPENDIX B IS NOT INCLUDED IN THE REPORT VERSION FOR PUBLIC RELEASE
DUE TO PRIVACY ISSUES.
Appendix C: Debris Line and Inundation Mapping Report:
HMTAP Task Order 411, Rapid Response, Aerial Radar 
Louisiana, Mississippi, and Alabama
Appendix C contains a summary report of the debris line and inundation mapping
performed under HMTAP Task Order 411: Rapid Response, Aerial Radar  Louisiana,
Mississippi, and Alabama. Photoanalysts used the post-event aerial imagery to estimate the
location of the debris line and the extent of inundation from Hurricane Katrina. As
described in the Mapping Methodology section of the report, this information developed
by the photoanalysts was used as the initial estimate of the WWL delineation, which was
further edited based on the field-collected data presented in Appendices A and B.
Appendix D: Notes on Analysis of WWL Data Points
Appendix D contains a record of the comparison of the photointerpreted data to the field
data and the actions taken to resolve any differences between the two. The Mapping
Methodology section of the report provides a description of how the field-collected data
presented in Appendices A and B were used to edit the photointerpreted debris line and
inundation limit, which were developed as explained in Appendix C. Appendix D provides
detailed descriptions of how each WWL data point was used to either confirm the proper
delineation of the WWL based on the photointerpreted data, or to edit this initial
delineation of the WWL where the two data sets did not agree.
Appendix E: WWL Maps
Appendix E contains the WWL Maps illustrating the location of the WWL. Summaries of
the WWL by parish are found in Table 8, which also highlights which of the following
map sheets correspond to each parish.
Appendix C -Debris Line and Inundation Mapping Report
Hurricane Katrina Rapid Response:
Debris Line and Inundation Mapping
20 January 2006
Background
As part of the Hurricane Katrina Rapid Response disaster relief efforts performed for the Federal Emergency Management Agency (FEMA), EarthData International, LLC (EarthData) supported URS Group, Inc. (URS) in its effort to identify areas of storm damage through mapping procedures.  EarthData produced and delivered mapping in ESRI shapefile (SHP) format containing delineation of debris lines caused by ocean surge and polygons surrounding areas inundated by floodwaters from both surge and freshwater flooding from Hurricane Katrina.  The areas mapped include the storm-struck areas along the Gulf Coast of Alabama,
Mississippi, and Louisiana.
The primary purpose of this mapping effort was to provide a comprehensive, region-wide inventory of areas damaged by Hurricane Katrina with as quick a turnaround as possible.  More specifically, the mapping products distinguished between areas damaged by high velocity floodwaters from surge along the coast (debris line), comparably slower moving floodwaters from surge and riverine flooding (inundation polygons), and high winds. FEMAs National Flood Insurance Program (NFIP) requires this type of data to ensure that Flood Insurance Studies (FISs) and Flood Insurance Rate Maps (FIRMs) provide reasonable risk information.
Area of Interest
Mapping coverage extended along the entire Gulf Coast region of Louisiana, Mississippi, and Alabama.  The area mapped was approximately 12,000 square miles and included portions of or all of the following counties:
1.Alabama Counties: Baldwin and Mobile
2.Mississippi Counties: Forrest, George, Greene, Hancock, Harrison, Jackson, Lamar, Marion, Pearl River, Perry, and Stone
3.Louisiana Parishes: Jefferson, Livingston, Orleans, Plaquemines, Saint Bernard, Saint Charles, Saint John the Baptist, Saint Tammany, Tangipahoa, and Washington
Imagery Source
EarthData used natural color digital aerial orthophotographs acquired between September 4 and September 17, 2005. The 3001, Inc. source imagery was acquired under an unrelated disaster response contract issued by the U.S. Army Corps of Engineers (USACE) to support their blue tarp task.  The imagery was made available to URS for use in Hazard Mitigation Technical Assistance Program (HMTAP)-related work.
Questions related to the imagery acquisition scope of work and technical specifications should be addressed to the USACE (Kevin Carlock, USACE, Rock Island District, 309-794-5249). The 3001, Inc. imagery provided to EarthData by URS covered approximately 3,600 tiles (4,077 x 4,092 pixels) and was projected in latitude/longitude coordinates.
Accuracy Standards
Digital orthophotography is normally created from aerial photographs combined in an aerotriangulation adjustment with ground and airborne positional control, which is rectified using a digital elevation model (DEM).  In the Hurricane Katrina response, USACE and their contractor, 3001, eliminated some of rigorous photogrammetric processing steps to expedite delivery of the imagery within 24 hours of acquisition. No ground control was acquired. Airborne Global Positioning System (GPS) and inertial measurement unit (IMU) data were used to provide an absolute orientation solution; however, a rigorous aerotriangulation block
adjustment was not performed. Due to the flatness of the terrain, it was also decided that planar rectification (using a flat surface) would be performed, rather than rectification to an actual DEM. The resulting orthophotography, therefore, does not meet National Map Accuracy Standards or Federal Geographic Data Committee (FGDC) standards for the final map scale.  No rigorous positional accuracy assessment was performed either by the USACE or URS due to 1) lack of extensive ground control check points and 2) turnaround time required for response and recovery products. Based on observations of positional
displacements of distinguishable linear features between adjacent flight lines and comparisons of existing geographical information system (GIS) data layers overlaid on the orthophotographs, EarthData estimates the horizontal accuracy of the 3001, Inc. orthophotography to be on the order of 10 meters. Again, this is not a rigorous accuracy assessment, but rather a subjective estimate of error based on the internal consistency of
the image dataset. When using derived mapping products, such as the debris line and inundation mapping described in this report, the end user should be cognizant of the magnitude of the potential spatial errors.
Mapping Products
EarthData used a production staff of eight professional cartographic analysts to produce and deliver mapping products for the above-mentioned areas stricken by Hurricane Katrina.  EarthDatas project manager and cartographic team leader/supervisor managed all of the day-to-day project functions throughout the life of the project.  This mapping effort began on September 9, 2005 and was completed on October 7, 2005.
The final deliverable products consisted of polygon shapefiles in units of meters projected to Universal Transverse Mercator (UTM) Zone 16, North American Datum of 1983 (NAD83). A separate shapefile was produced for each of the mapping featuresone for the debris line and one for inundation polygons.
Mapping analysts used 3001, Inc. imagery to interpret areas of storm surge damage along the coast marked by debris lines as well as inland areas that experienced surge and/or riverine flooding.  As a secondary source, analysts used 10-foot contours produced from Light Detection and Ranging (LiDAR) and U.S. Geological Survey (USGS) DEM datasets covering the areas of interest.  The contours were referenced with the imagery to locate low-lying areas where the potential for flooding was high and debris would likely collect.
EarthDatas staff used preliminary high water mark points provided by URS as another ancillary reference to locate areas field surveyors identified as flooded.
Using the imagery source provided along with the ancillary sources listed above, EarthData mapped the debris line where visual evidence of the high velocity ocean surge was present.  For instance, significant debris from man-made structures, sand, mud, and other biomass would collect along lines where the surge carried it over land.
Additional indications of ocean surge extended along the coast, where trees and vegetation had turned brown due to salt water inundation. Flooding further inland was determined by visual evidence of standing water or deposited debris and mud along bays, rivers, lakes, and other water bodies farther inland; receding floodwaters left the debris behind.  In areas where the imagery was either void, corrupt, or covered by clouds, a polygon was digitized around the area and labeled as obscured.
Software Applications
EarthData used a combination of ESRI ArcCatalog and ArcView software to create the working file templates.  These templates, or seed files, set all of the parameters and applicable attribution that was later populated in the compilation stage, ensuring consistency in the file structure across the entire project.
Digitizing of the debris lines and flood polygons was performed using both ESRI ArcView and ArcMap software packages. All final data were merged to create a single file in ESRI shapefile format for each of the two separate featured themes: the debris line and inundation polygons.  All shapefiles were reprojected from latitude/longitude to the UTM Zone 16, NAD83 using ArcCatalog.
Interpretation Obstacles
EarthDatas analysts used professional interpretation and judgment in identifying areas damaged from ocean surge and inland flooding based on the sources of information provided.  Due to the urgency associated with the hurricane response, some scattered areas of the aerial imagery contained cloud cover. Lighting conditions were often less than optimal for interpretation, and it was not physically possible to photograph the entire project area coincident with actual storm surge and peak inundation conditions.  Mapping analysts were
confronted with the need to make subjective decisions in interpretation.
Figure 1 shows a case of inland flooding along a river, where the high water had partially receded by the time the photograph was taken. In such cases, analysts designated any areas covered with mud, sand, or silt, as well as areas where the color of the ground or vegetation indicated a high level of moisture due to recent inundation, as flooded.
Figure 1 - Aerial photo of flooding along a river.
When flood waters recede quickly before the photographs are taken, analysts are confronted with a more complex interpretation assessment.  In these cases, analysts look for signatures in the photographs, such as leaning trees, standing water, deposited debris (mud, silt, vegetation, etc.) and other features, that indicate the presence of inland flood waters.  Figure 2 depicts an area which was interpreted to have been entirely inundated with water that receded before the photo was taken. This was determined by the presence of mud, fallen trees and saturated ground indicated by brown coloration throughout the image.
Figure 2 - Aerial photo of brown vegetation
Figure 3 represents an area where the presence of marsh results in a unique situation whereby debris no longer collects as it would typically do on dry land.  What is normally a visible debris line on dry land becomes less obvious for photo-interpretation when over marsh and other standing water bodies.  In such cases, analysts may use contour lines, the presence of high water marks, deposited mud and silt, and/or any damage to vegetation that has been submerged by flood waters.  The marsh in Figure 3 is evident in the lower left and lower right sectors of the image.  URS engineers judged final placement of the wind/water line in
such areas where photo interpretation alone was not conclusive.
Figure 3 - Aerial photo of marsh outside of the city
Figure 4 depicts the presence of multiple debris lines.  In such cases, the analyst must decide whether all debris was deposited by the ocean surge or some debris was later swept up by inland flooding caused by heavy rain.  If tide waters are present along the coast, it can result in multiple debris lines being left behind.
Typically, the analyst will place the debris line at the most evident and consistent debris line or along the furthest inland point (high water mark).
Figure 4 - Aerial photo of multiple debris lines.
Coastal areas containing salt marshes and other low-lying areas such as that represented in Figure 5 can pose a challenge to photo-interpreters delineating flood waters.  An analyst must determine whether or not to represent an area as flooded.  There are many cases in which land appears to be flooded, but the area is really a marsh and always has saturated characteristics.  In these cases analysts often review other sources such as secondary maps, historical data, and field surveyed conditions. Analysts also look for deposited mud and the condition of nearby vegetation to determine whether an area has been flooded or whether it is simply a marsh.
Figure 5 - Aerial photo of low lying areas affected by flood waters
Appendix D1
Flagger Comments
Comments from Field Crew Reviewers
Comment:Lakefront Airport was flooded - shown as outside inundation area on map
Map Panel:Spanish Fort
HWM/WWL Points Nearby:KLAC 88-20
Action:Expanded inundation polygon to include the airport.
Comment:Points near levee in St. Bernard Parish do seem to be pretty accurate in showing the limit of flooding. There was some dry area there.
Map Panel:Chalmette
HWM/WWL Points Nearby: KLAC 01-34, 01-35, 01-40, 01-38
Action:If anything, the HWM data supports that the flooding went all the way up to the levee in this area [01-40 (4 ft), 01-34 (5.8 ft), 01-35 (6.3 ft), 01-38 (4.4 ft)].  Leave as shown on photointerpreted inundation limits.
Comment:Along Lake Pontchartrain by the levee east of the Lakefront Airport, there was some dry ground as land sloped upwards
Map Panel:Spanish Fort and Little Woods
HWM/WWL Points Nearby:KLAC 08-19, 06-25, 06-28, 06-29, 06-30, 06-31
Action:Made these points into WWL points 06-28 (0.8), 06-29 (0.9), 06-30 (1.2), 06-31 (1.5) and looked at topo to confirm that existing boundary made sense with topo.
Comment:Swampy areas of St. Bernard Parish east of inundation polygon was flooded - limited access to this area.  Swampy areas of Plaquemines between the coast and the river are also thought to have been affected by surge.
Map Panel:North, east, and south of Delacroix. Happy Jack, Port Sulphur, etc.
HWM/WWL Points Nearby:
Action:Made a separate polygon coverage to highlight marshy areas where there were likely surge affects including coastal areas in St. Bernard, Plaquemines, LaFourche and Terrebonne.
Comment:Flooding was mostly limited to river floodplains west of Pontchartrain and in the Lake Maurepas area
Map Panel:Killian, Mt. Airy, Reserve
HWM/WWL Points Nearby:KLAC 03-05, 03-06, 03-07, 03-08, 03-09, and 03-10
Action:Used the topo and HWM data to delineate flooding/WWL here
Comment:On the western side of the industrial canal, in New Orleans east, points 07-47, 07-48 likely do define the WWL.  The street St. Claude Ave seemed to have been the WWL line for the most part. On the east side of the Industrial Canal, the water got closer to the levee than on the New Orleans side if not all the way to the levee.
Map Panel:New Orleans East
HWM/WWL Points Nearby:KLAC 07-47 and 07-48
Action:Made these points WWL points
Appendix D2 - Notes WWL Data Points
Parish/ WWL Data Point:Jefferson/KLAC-04-10
Source of Flooding:Coastal
Map Panel:Indian Beach SW
Surveyed Elev (ft NAVD 88):9.4
Elev (from 2-ft contours):Elevation Data not available for this topo quad
Flood Elev (from 2-ft contours):Elevation Data not available for this topo quad
Distance to Flood Boundary (ft):	320
Action:No action.
Reasoning:	Point along levee on Lake Pontchartrain that held.
Parish/ WWL Data Point:Jefferson/KLAC-04-11
Source of Flooding:Coastal
Map Panel:Indian Beach SW
Surveyed Elev (ft NAVD 88):11.6
Elev (from 2-ft contours):Elevation Data not available for this topo quad
Flood Elev (from 2-ft contours):Elevation Data not available for this topo quad
Distance to Flood Boundary (ft):	0
Action:	No action.
Reasoning:	Point along levee on Lake Pontchartrain that held.
Parish/ WWL Data Point:Jefferson/KLAC-04-13
Source of Flooding:Canal/Coastal
Map Panel:New Orleans West NW
Surveyed Elev (ft NAVD 88):-3.9
Elev (from 2-ft contours):-4
Flood Elev (from 2-ft contours):Along inland canals where enough flood inundation is mapped
Distance to Flood Boundary (ft):	Along inland canals where enough flood inundation is mapped
Action:Used contour data to create WWL with boundary at elevation -2 to -4.
Reasoning:	No inundation polygon was shown in Jefferson Parish along Lake Pontchartrain from aerial imagery photointerpretation. Reports and comments from field crews and the number of coastal HWMs taken in this area clearly indicate there was significant flooding here. Unlike other nearby parishes in the New Orleans area, flooding in Jefferson Parish was drained relatively quickly and many areas experienced only shallow flooding. Therefore, there may not have been obvious signs of flooding on the imagery. There were enough datapoints (both WWL and coastal HWM) and comments from field crews to confirm there was widespread flooding here.
Parish/ WWL Data Point:Jefferson/KLAC-04-14
Source of Flooding:Coastal
Map Panel:New Orleans West NW
Surveyed Elev (ft NAVD 88):-3.7
Elev (from 2-ft contours):-4
Flood Elev (from 2-ft contours):Along inland canals where enough flood inundation is mapped
Distance to Flood Boundary (ft):	Along inland canals where enough flood inundation is mapped
Action:Used contour data to create WWL with boundary at elevation -2 to -4.
Reasoning:	No inundation polygon was shown in Jefferson Parish along Lake Pontchartrain from aerial imagery photointerpretation. Reports and comments from field crews and the number of coastal HWMs taken in this area clearly indicate there was significant flooding here. Unlike other nearby parishes in the New Orleans area, flooding in Jefferson Parish was drained relatively quickly and many areas experienced only shallow flooding. Therefore, there may not have been obvious signs of flooding on the imagery. There were enough datapoints (both WWL and coastal HWM) and comments from field crews to confirm there was widespread flooding here.
Parish/ WWL Data Point:Jefferson/KLAC-04-15
Source of Flooding:Coastal
Map Panel:New Orleans West NW
Surveyed Elev (ft NAVD 88):-3.8
Elev (from 2-ft contours):-4
Flood Elev (from 2-ft contours):Along inland canals where enough flood inundation is mapped
Distance to Flood Boundary (ft):	Along inland canals where enough flood inundation is mapped
Action:Used contour data to create WWL with boundary at elevation -2 to -4.
Reasoning:	No inundation polygon was shown in Jefferson Parish along Lake Pontchartrain from aerial imagery photointerpretation. Reports and comments from field crews and the number of coastal HWMs taken in this area clearly indicate there was significant flooding here. Unlike other nearby parishes in the New Orleans area, flooding in Jefferson Parish was drained relatively quickly and many areas experienced only shallow flooding. Therefore, there may not have been obvious signs of flooding on the imagery. There were enough datapoints (both WWL and coastal HWM) and comments from field crews to confirm there was widespread flooding here.
Parish/ WWL Data Point:Jefferson/KLAC-04-34
Source of Flooding:Coastal
Map Panel:Indian Beach SW
Surveyed Elev (ft NAVD 88):9.4
Elev (from 2-ft contours):Elevation Data not available for this topo quad
Flood Elev (from 2-ft contours):Elevation Data not available for this topo quad
Distance to Flood Boundary (ft):	140
Action:No action.
Reasoning:	Point along levee on Lake Pontchartrain that held.
Lafourche (0)
Parish/ WWL Data Point:Livingston (NIS)/KLAC-02-09
Source of Flooding:Coastal
Map Panel:Killian
Surveyed Elev (ft NAVD 88):5.4
Elev (from 2-ft contours):6
Flood Elev (from 2-ft contours):N/A
Distance to Flood Boundary (ft):N/A
Action:Went up canals with inundation polygon.
Reasoning:	Inundation line seems to match with surveyed elevations through here, except for canals where WWL datapoint was taken.
Parish/ WWL Data Point:Orleans/KLAC-01-20
Source of Flooding:Breached Levee
Map Panel:New Orleans East NW
Surveyed Elev (ft NAVD 88):0.7
Elev (from 2-ft contours):0
Flood Elev (from 2-ft contours):-12
Distance to Flood Boundary (ft):	7100
Action:  Mapped as 'islands' of high ground.
Reasoning:	Small area that appears to be high ground, according to imagery and WWL datapoints.
Parish/ WWL Data Point:Orleans/KLAC-01-33
Source of Flooding:Breached Levee
Map Panel:New Orleans East
Surveyed Elev (ft NAVD 88):2.3
Elev (from 2-ft contours):2
Flood Elev (from 2-ft contours):4
Distance to Flood Boundary (ft):	500
Action: Moved inundation boundary out to this point - use topo as guide.
Reasoning:	Imagery and flagger observations support that flooding went further inland here.
Parish/ WWL Data Point:Orleans/KLAC-02-13
Source of Flooding:Breached Levee
Map Panel:Spanish Fort SW
Surveyed Elev (ft NAVD 88):1.6
Elev (from 2-ft contours):2
Flood Elev (from 2-ft contours):-2
Distance to Flood Boundary (ft):	7700
Action:	No action.
Reasoning:	Looks like levee along this canal worked ok and kept water out, but areas are flooded from other canal break where water has come back up into these areas.
Parish/ WWL Data Point:Orleans/KLAC-02-14
Source of Flooding:Breached Levee
Map Panel:Spanish Fort SW
Surveyed Elev (ft NAVD 88):1.4
Elev (from 2-ft contours):2
Flood Elev (from 2-ft contours):-2
Distance to Flood Boundary (ft):	7900
Action:	Left inundation polygon as is.
Reasoning:	Looks like levee along this canal worked ok and kept water out, but areas are flooded from other canal break where water has come back up into these areas.
Parish/ WWL Data Point:Orleans/KLAC-02-16
Source of Flooding:Coastal
Map Panel:Spanish Fort SE
Surveyed Elev (ft NAVD 88):10.7
Elev (from 2-ft contours):8
Flood Elev (from 2-ft contours):-2
Distance to Flood Boundary (ft):	3067
Action:Edited inundation polygon to show portions of elevated area of levee as outside of flooding.
Reasoning:	Levee worked in this area.
Parish/ WWL Data Point:Orleans/KLAC-02-17
Source of Flooding:Coastal
Map Panel:Spanish Fort SE
Surveyed Elev (ft NAVD 88):14.5
Elev (from 2-ft contours):12
Flood Elev (from 2-ft contours):-2
Distance to Flood Boundary (ft):	5000
Action:	Edited inundation polygon to show portions of elevated area of levee as outside of flooding.
Reasoning:	Levee worked in this area.
Parish/ WWL Data Point:Orleans/KLAC-02-18
Source of Flooding:Coastal
Map Panel:Spanish Fort SE
Surveyed Elev (ft NAVD 88):12.9
Elev (from 2-ft contours):14
Flood Elev (from 2-ft contours):-2
Distance to Flood Boundary (ft):	7900
Action:	Edited inundation polygon to show portions of elevated area of levee as outside of flooding.
Reasoning:	Levee worked in this area.
Parish/ WWL Data Point:Orleans/KLAC-02-21
Source of Flooding:Breached Levee
Map Panel:Spanish Fort SW
Surveyed Elev (ft NAVD 88):1.7
Elev (from 2-ft contours):2
Flood Elev (from 2-ft contours):-2
Distance to Flood Boundary (ft):	7400
Action:	Left inundation polygon as is.
Reasoning:	Looks like levee along this canal worked ok and kept water out, but areas are flooded from other canal break where water has come back up into these areas.
Parish/ WWL Data Point:Orleans/KLAC-02-22
Source of Flooding:Coastal
Map Panel:Spanish Fort SW
Surveyed Elev (ft NAVD 88):12.6
Elev (from 2-ft contours):14
Flood Elev (from 2-ft contours):-2
Distance to Flood Boundary (ft):	4900
Action:	Edited inundation polygon to show portions of elevated area of levee as outside of flooding.
Reasoning:	Levee worked in this area.
Parish/ WWL Data Point:Orleans/east of KALC-02-22
Source of Flooding:Spanish Fort SW
Map Panel:not an actual WWL point
Surveyed Elev (ft NAVD 88):
Elev (from 2-ft contours):not an actual WWL point
Flood Elev (from 2-ft contours):not an actual WWL point
Distance to Flood Boundary (ft):	not an actual WWL point
Action:	From imagery, area shown as inundated actually stayed dry. Adjusted inundation polygon to show this area outside of flooded area.
Reasoning:	Imagery supports that this area did not flood.
Parish/ WWL Data Point:Orleans/KLAC-04-16
Source of Flooding:Riverine
Map Panel:Spanish Fort
Surveyed Elev (ft NAVD 88):1.3
Elev (from 2-ft contours):2
Flood Elev (from 2-ft contours):2
Distance to Flood Boundary (ft):	0
Action:No action.
Reasoning:	Very near existing boundary. No action.
Parish/ WWL Data Point:Orleans/KLAC-04-17
Source of Flooding:Riverine
Map Panel:Spanish Fort
Surveyed Elev (ft NAVD 88):7.7
Elev (from 2-ft contours):8
Flood Elev (from 2-ft contours):6
Distance to Flood Boundary (ft):	230
Action:	No action.
Reasoning:	Point on levee, but areas on both sides of levee in this vicinity were dry.
Parish/ WWL Data Point:Orleans/KLAC-04-18
Source of Flooding:Riverine
Map Panel:Spanish Fort
Surveyed Elev (ft NAVD 88):16.6
Elev (from 2-ft contours):14
Flood Elev (from 2-ft contours):6
Distance to Flood Boundary (ft):	330
Action:	No action.
Reasoning:	Point on levee, but areas on both sides of levee in this vicinity were dry.
Parish/ WWL Data Point:Orleans/KLAC-04-21
Source of Flooding:Coastal
Map Panel:New Orleans East NW
Surveyed Elev (ft NAVD 88):1.5
Elev (from 2-ft contours):0
Flood Elev (from 2-ft contours):-12
Distance to Flood Boundary (ft):1750
Action:	Mapped as 'islands' of high ground.
Reasoning:	Small area that appears to be high ground, according to imagery and WWL datapoints.
Parish/ WWL Data Point:Orleans/KLAC-04-25
Source of Flooding:Breached Levee
Map Panel:New Orleans East
Surveyed Elev (ft NAVD 88):1
Elev (from 2-ft contours):2
Flood Elev (from 2-ft contours):2
Distance to Flood Boundary (ft):	75
Action:	No action.
Reasoning:Right near existing boundary.
Parish/ WWL Data Point:Orleans/KLAC-04-26
Source of Flooding:Breached Levee
Map Panel:New Orleans East
Surveyed Elev (ft NAVD 88):1.73
Elev (from 2-ft contours):4
Flood Elev (from 2-ft contours):2
Distance to Flood Boundary (ft):	1000
Action:	Moved inundation boundary out to this point - use topo as guide.
Reasoning:	Imagery and flagger observations support that flooding went further inland here.
Parish/ WWL Data Point:East New Orleans
Map Panel:Little Woods & Chef Menteur
Surveyed Elev (ft NAVD 88): note that there are not HWMs or WWL points here.  Swampy, undeveloped area without access.
Parish/ WWL Data Point:Plaquemines/KLAC 05-18
Source of Flooding:Riverine
Map Panel:Bertrandville
Surveyed Elev (ft NAVD 88):16.3
Elev (from 2-ft contours):14
Flood Elev (from 2-ft contours):8
Distance to Flood Boundary (ft):	260
Action:	No action.
Reasoning:	Point is close to inundation boundary. Polygon is contained within levee and point is on top of levee.
Parish/ WWL Data Point:Plaquemines/KLAC 08-06
Source of Flooding:Riverine
Map Panel:Port Sulphur
Surveyed Elev (ft NAVD 88):1.4
Elev (from 2-ft contours):2
Flood Elev (from 2-ft contours):12
Distance to Flood Boundary (ft):	0
Action:	No action. Point is right along inundation border.
Reasoning:	Point is along border.
St. Bernard (0)
Parish/ WWL Data Point:St. Charles/KLAC-02-02
Source of Flooding:Coastal
Map Panel:Luling
Surveyed Elev (ft NAVD 88):13.6
Elev (from 2-ft contours):14
Flood Elev (from 2-ft contours):14
Distance to Flood Boundary (ft):	10
Action:Along levee. No action.
Reasoning:	Flooding contained in levee system in this area along MS River.
Parish/ WWL Data Point:St. Charles/KLAC-02-03
Source of Flooding:Coastal
Map Panel:Luling
Surveyed Elev (ft NAVD 88):15.7
Elev (from 2-ft contours):14
Flood Elev (from 2-ft contours):16
Distance to Flood Boundary (ft):	0
Action:	Along levee. No action.
Reasoning:	Flooding contained in levee system in this area along MS River.
Parish/ WWL Data Point:St. Charles/KLAC-02-04
Source of Flooding:Coastal
Map Panel:Luling
Surveyed Elev (ft NAVD 88):17.8
Elev (from 2-ft contours):18
Flood Elev (from 2-ft contours):16
Distance to Flood Boundary (ft):	87
Action:	Along levee. No action.
Reasoning:	Flooding contained in levee system in this area along MS River.
Parish/ WWL Data Point:St. Charles/KLAC-02-05
Source of Flooding:Coastal
Map Panel:Des Allemands
Surveyed Elev (ft NAVD 88):3.5
Elev (from 2-ft contours):3
Flood Elev (from 2-ft contours):4
Distance to Flood Boundary (ft):
Action:	No inundation mapped here - left as it was.
Reasoning:	Only point for area along Bayou des Allemands. Not enough info for mapping
WWL.
Parish/ WWL Data Point:St. Charles/KLAC-20-01
Source of Flooding:Coastal
Map Panel:Hahnville
Surveyed Elev (ft NAVD 88):13.5
Elev (from 2-ft contours):10
Flood Elev (from 2-ft contours):2
Distance to Flood Boundary (ft):	65
Action:	Along levee. No action.
Reasoning:	Flooding contained in levee system in this area along MS River.
Parish/ WWL Data Point:St. James/KLAC-20-03
Source of Flooding:Coastal
Map Panel:Lutcher
Surveyed Elev (ft NAVD 88):13.6
Elev (from 2-ft contours):14
Flood Elev (from 2-ft contours):4
Distance to Flood Boundary (ft):	90
Action:	Brought inundation border out to point along levee from 20-02.
Reasoning:	Inundation border follows levee through this area. Point taken on levee.
Parish/ WWL Data Point:St. John the Baptist/KLAC-03-09
Source of Flooding:Coastal
Map Panel:Laplace
Surveyed Elev (ft NAVD 88):3.9
Elev (from 2-ft contours):6
Flood Elev (from 2-ft contours):4
Distance to Flood Boundary (ft):	4100
Action:	No action.
Reasoning:	Flat area through here that appears to be highly vegetated, undeveloped swamp, shown as being inundated according to photointerpretation. Would seem that much of this swampy area would have been flooded, but there is not much access or structures for finding HWMs with the swamp, so left inundation boundary as it was.
Parish/ WWL Data Point:St. John the Baptist/KLAC-03-10
Source of Flooding:Coastal
Map Panel:Laplace
Surveyed Elev (ft NAVD 88):5.7
Elev (from 2-ft contours):6
Flood Elev (from 2-ft contours):4
Distance to Flood Boundary (ft):	4100
Action:	No action.
Reasoning:	Flat area through here that appears to be highly vegetated, undeveloped swamp, shown as being inundated according to photointerpretation. Would seem that much of this swampy area would have been flooded, but there is not much access or structures for finding HWMs with the swamp, so left inundation boundary as it was.
Parish/ WWL Data Point:St. John the Baptist/KLAC-20-02
Source of Flooding:Coastal
Map Panel:Reserve
Surveyed Elev (ft NAVD 88):12.9
Elev (from 2-ft contours):14
Flood Elev (from 2-ft contours):20
Distance to Flood Boundary (ft):	175
Action:	Along levee. No action.
Reasoning:	Flooding contained in levee system in this area along MS River.
Parish/ WWL Data Point:St. Tammany/KLAC-01-03
Source of Flooding:Coastal
Map Panel:Lacombe SW
Surveyed Elev (ft NAVD 88):7.57
Elev (from 2-ft contours):6
Flood Elev (from 2-ft contours):4
Distance to Flood Boundary (ft):730
Action:	Moved line out to 8-ft contour in this area, about 8,000-ft long stretch.
Reasoning:	Imagery shows discoloration of vegetation from flooding beyond current inundation boundary. Inland polygon doesn't make sense with topo.
Parish/ WWL Data Point:St. Tammany/KLAC-01-13
Source of Flooding:Coastal
Map Panel:Lacombe NW
Surveyed Elev (ft NAVD 88):10.85
Elev (from 2-ft contours):10
Flood Elev (from 2-ft contours):4
Distance to Flood Boundary (ft):	500
Action:	Moved line out to 10-ft contour line.
Reasoning:	Imagery shows discoloration of vegetation from flooding beyond current inundation boundary and point supports that inundation went further inland.
Parish/ WWL Data Point:St. Tammany/KLAC-07-08
Source of Flooding:Coastal
Map Panel:Mandeville NW
Surveyed Elev (ft NAVD 88):9.23
Elev (from 2-ft contours):8
Flood Elev (from 2-ft contours):10
Distance to Flood Boundary (ft):	450
Action:No action.
Reasoning:	Flaggers estimate flood depth is 1.3 ft at this point and area is relatively flat, so inundation could have spread farther inland, as indicated by inundation polygons.
Parish/ WWL Data Point:St. Tammany/KLAC-07-09
Source of Flooding:Coastal
Map Panel:Mandeville NW
Surveyed Elev (ft NAVD 88):10.32
Elev (from 2-ft contours):8
Flood Elev (from 2-ft contours):8
Distance to Flood Boundary (ft):480
Action:	Moved line to follow 10-ft contour closer east of point.
Reasoning:	Imagery shows discoloration of vegetation in this area beyond flood inundation. HWMs through here (07-02, 07-03) show elevation of 9 to 10 ft.
Parish/ WWL Data Point:St. Tammany/KLAC-07-11
Source of Flooding:Coastal
Map Panel:Covington
Surveyed Elev (ft NAVD 88):7.8
Elev (from 2-ft contours):6
Flood Elev (from 2-ft contours):2
Distance to Flood Boundary (ft):	3500
Action:	Moved flooding inland using imagery, topo (~8ft) and point as guide.
Reasoning:	Based on imagery and point, need to move flooding further inland. Flaggers went into subdivision to find point where there was an estimated 1.3-ft depth.
Parish/ WWL Data Point:Terrebonne/KLAC-02-01
Source of Flooding:Coastal
Map Panel:Montegut
Surveyed Elev (ft NAVD 88):2.1
Elev (from 2-ft contours):3
Flood Elev (from 2-ft contours):no inundation mapped here
Distance to Flood Boundary (ft):no inundation mapped here
Action:	Kept for reference, but noting that this area is swampy, with limited access. Do not have enough points for full WWL or inundation polygon here.
Reasoning:	Keep for reference, but we're not going to use with WWL or inundation polygon since there is only one point.
Parish:Tangipahoa
Undeveloped swampy area. No WWL points.  HWMs are concentrated in small areas along highways/roadways.