Transcript Slide 1

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Presentation Outline
 Map Modernization & Risk MAP Overview
 Risk MAP Early Demonstration Purpose
 Study Area Selection/Proposal
 Product Results and Findings
 Stakeholder Feedback
 Mapping Partner Recommendations
 Moving forward with Risk MAP
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FEMA Map Modernization Program
 Map Mod brought NFIP
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
mapping into 21st century
Ran from 2003-2010
Transition from paper to digital
format
 Significant advantages in capability
and precision
 New digital SFHA’s for 92% of
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the population
Encourage use of quality local
data
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FEMA Vision for Risk MAP

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
FEMA Risk Mapping, Assessment, and
Planning (MAP) Program
 Deliver quality flood data that increases
public awareness
 Initiate mitigation measures to reduce risk
and loss of life and property
 Transform traditional flood mapping to
better integrate:
– Identification
– Assessment
– Communication
– Planning for
– Mitigation of flood related risks
Ensure 80% of the Nation’s flood hazards are
current
Update flood hazard data for 100% of the
populated coastal areas in the Nation
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Risk MAP Early Demonstration Purpose
 Early Demonstration Projects
Validate Risk MAP products increase
value to program vision
Emphasize production efficiencies
and innovations
Update Guidance
Ascertain product refinement
Determine costs
Stakeholder feedback
Risk MAP Development
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Early Demonstration Requirements
 Project study area funded prior to




2010, pre-appeal phase
Strong Regional Support
Efforts could not exceed $100k
Good elevation data
Completion by February 2011,
lessons learned integrated prior
to FY2011 Risk MAP
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Early Demonstration Area Selection,
Madison County, AL
Madison County Project
 Effective 1998
 FY2008/2009 funding
 Strong stakeholder relationship,
OWR and AMEC
 Current ground surface data:
LiDAR 2007
 Area which will benefit from
products, mitigation potential
 Existing county revision, several
detailed studies
Produce:
 Changes Since Last FIRM
 Flood Risk Probability Grids
 Depth Grids
 Flood Risk Report
 Flood Risk Map
 Two Stakeholder Meetings
Enhanced:
 Annualized Loss Estimates
 Velocity Grids
 Areas of Mitigation Interest
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Changes Since Last FIRM
 ESRI model builder tool developed
 Data stored in Flood Risk Database
 FRR shows summaries SFHAs

affected
Greatest level of effort:
 attributing factors contributing to the
shape of the SFHA
 Population and buildings affected
CSLF example: Bradford Creek, Madison, AL
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Areas of Mitigation Interest
Channel Improvements
Significant
proposed
and recent
development
Urbanization
Undersized
culverts
Floodplain
pinch points
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Areas of Mitigation Interest
Flood Control Structures
Risk “hot
spot” areas
Home
buyouts
Previous
claims
Locations
of
successful
mitigation
projects
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Water Surface Elevation and
Flood Depth Grid
 By products of floodplain


mapping
Mosaicing rasters can
horizontally skew data
Resampling model grids can
reduce the magnitude of the
skew
 Resulted in average horizontal
skew of less than one foot
Initial Raster Mosaicing
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Velocity Grid Methodologies
 HEC-GeoRAS and RAS Mapper methodologies were considered
 HEC-GeoRAS - smoothest and most accurate velocity grid
 Floodplain polygons required inputs for velocity grid creation
 AFG chosen over HEC-GeoRAS
Tiling
Using AFG Floodplain
Using Geo-RAS Floodplain
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Velocity Grid Results
Velocity grid example: confluence of Indian
Creek Trib 1 and Indian Creek, Intersection
of Slaughter Road and Interstate 565
Huntsville, AL, 100 yr event
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(Linear)
Percent Chance of Flooding Equations
Ground Elevation
(WSEL – Depth Grid)
% Annual
Chance
(Log)
30 -Year Percent Chance




log10 pannual upper  log10 pannual lower

WSEupper  WSElower
  log10 pannual upper  GroundElevation
log10  pannual   
1 - (1 - p)30
pannual  10
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Percent Chance of Flooding Methodology
 Procedure derived based on FEMA guidance
 ESRI model builder tool created
 Grids were created for each of the selected flooding source intervals
and mosaiced by county
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Percent Annual Chance and Percent 30-Year
Results
Aldridge Creek, near Valley Hill Country Club area, Huntsville, AL
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Flood Risk Assessment
 Flood Risk Assessment Products
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(10%, 4%, 2%, 1%, 0.2%, and annual
chance)
Area (Risk, Very Low to Very High)
Classification (Residential,
Commercial, Other)
Population
Average Value (buildings/census
block)
Total Loss
Building Loss
Content Loss
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Result Discrepancies
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Locally Supplied Building Data

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Building footprints
First floor elevations
Constructions materials
Number of stories or height
Year built/age/building quality
Building value
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Content value
Building type
Latitude/Longitude
Occupancy class
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Flood Risk Assessment Results
 FEMA provided a Level 1 HAZUS risk assessment for each census
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
block.
Results were poor in quality.
Classified all census blocks as residential in Madison County.
Community stakeholders noted areas of high risk labeled as very low
risk in HAZUS.
Enhanced flood risk assessment not possible with current version of
HAZUS, needs to be revised.
Estimated Potential Losses for Flood Event Scenarios
Total Inventory
Percent
of
Estimated Value
Total
10% (10-yr)
2% (50-yr)
1% (100-yr)
0.2% (500-yr)
Annualized ($/yr)
Dollar Losses
Loss
Ratio
Dollar Losses
Loss
Ratio
Dollar Losses
Loss
Ratio
Dollar Losses
Loss
Ratio
Dollar Losses
Loss
Ratio
Residential
Building/Contents
$30,093,892,200
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
Commercial
Building/Contents
$7,409,054,950
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
Other Building/Contents
$4,663,139,042
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
Total Building/Contents
$42,166,086,192
100%
$396,750,000
1%
$523,033,000
1%
$579,867,000
1%
$701,102,000
2%
$47,067,000
<1%
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
$42,166,086,192
100%
$396,750,000
1%
$523,033,000
1%
$579,867,000
1%
$701,102,000
2%
$47,067,000
<1%
Business Disruption
TOTAL
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Watershed Flood Risk Report
 Provides a summary of all
flood risk information in
single source.
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Flood Risk Map
 Countywide base data
 FEMA AAL
 Contributing Engineering Factors
 Areas of Mitigation Interest
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Community Feedback - CSLF
Integration
• Easily incorporated
Improvement
• No large potential
Community Benefit
• Could help relate flood risk to public
Concerns
• Public could blame community leaders for
changes
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Community Feedback – Analysis Grids
Integration
• Not easily integrated into daily routines
Improvement
• No large potential
Community Benefit
• Help identify trouble areas
Concerns
• Unable to determine BFE’s in lieu of FIRMs
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Community Feedback – Flood Risk
Assessment
Integration
• Neutral
Improvement
• Community specific data incorporated
Community Benefit
• General information purposes only
Concerns
• Accuracy
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Community Feedback – Areas of
Mitigation Interest
Integration
• Areas already known by community
Improvement
• Dependent upon community participation
Community Benefit
• Minimal
Concerns
• Liability
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Community Feedback – FRR/FRM
Integration
• General information purposes only
Improvement
• May be difficult to use in paper format
Community Benefit
• Not helpful
Concerns
• Funding towards more detailed studies
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Mapping Partner Recommendations
CSLF
Flood Depth and
Analysis Grids
Flood Risk
Assessment
FRR/FRM
• More detailed guidance
• Start and end of flooding source effects procedure
• Additional data field for inconsistent flooding source
• Specified naming convention and cell sizes for all grid
products
• Guidance for mosaicing rasters
• New version of HAZUS needed
• Account for incomplete community datasets
• Language and graphic recommendations
• Map format recommendations
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Revised FEMA Guidance, Appendix N & O
CSLF
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Contributing engineering factor
became a variable attributed with
12 possible fields
Ex: New Terrain Data- If new terrain
data was introduced and that new
data caused the floodplain
boundaries to change, the attribute
would be “True”
No procedure for start/end of
flooding sources included.
No new field for new flood source
added
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Revised FEMA Guidance, Appendix N & O
Flood Depth Analysis
Grids
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Defined naming convention and
raster cell size (resolution) for all
raster datasets =10 meters (32.808
feet).
If higher resolution depth or
analysis rasters are produced,
Mapping Partners shall submit
outside of the FRD.
Section detailing combining depth
grids at a confluence, acceptable
depth difference (+/- 0.5 ft),
engineering judgment applied when
exceeds
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Revised FEMA Guidance, Appendix N & O
Flood Risk Assessment
 Guidance details MR4 version cannot calculate annualized loss but
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does include a HAZUS alternative loss calculation formula.
Guidance does not address partial dataset information entered into
the Comprehensive Data Management System (CDMS) but defers
users to CDMS manual.
MR5 available and new version of CDMS should be available soon
AOMI’s
 Remains point feature
 Defines how to create AOMI Data including detailing the data mining
process
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Revised FEMA Guidance, Appendix N & O
FRR
 Guidelines are not mandatory
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
and some portions may be
tailored by writer
Template Tables may be edited
based on available information
Template text edited
FRM
 Purpose of FRM is intended for
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
facilitation purposes to involve
communities
Legend modified- specifies
AOMIs
Most recommendations followed
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Moving Forward with Risk MAP
Community
FEMA
Other Parties
Mapping Partner
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Mutually Beneficial Partnerships
 Develop a framework that collects information on the effectiveness of
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partnerships
Ensure Risk MAP products from partnerships are complementary and
not duplicative
Collaborate with partners to improve understanding and encourage
action
Provide support to partners to include policies, procedures,
guidelines, and training
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Outreach and Communications
Flood
Insurance
Policy Holders
General Public
Planners
Engineers
Surveyors
Environmental
Groups
Realtors,
Homebuilders
Insurance
Agents
Lenders
State and local
representatives
Other Federal
Agencies
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Outreach and Communications
Reaching Stakeholders
 Conferences
 Media Relations
 Community Meetings
 Social Media
 Facebook
 Twitter
 Web Applications
 Phone apps
 Other
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Presentation Conclusions
 Risk MAP Early Demonstration Project was successful
Emphasized production efficiencies and innovations
Presented product cost estimates
Provided Stakeholder feedback
Provided Mapping Partner feedback
Aided in update to guidance
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