North Carolina Floodplain Mapping Program
Kenneth Ashe, P.E., CFM
Assistant Director GTM
July 24, 2008
Effects of Hurricane Floyd on North
Carolina
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Goldsboro, NC
51 deaths
$3.5 - $6 billion in
damages to homes,
businesses, roads,
and infrastructure
Damage ~¼ - ½ of
1999 Tax Revenue
31,000 jobs lost
Origin of the NC Floodplain
Mapping Program
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23+ Federally declared disasters in NC since 1989
Hurricane Floyd in 1999 revealed limitations of outdated FIRMs in NC
~ 80% of the properties damaged or destroyed not shown in the SFHA
Most flood maps in NC were older than 12 years – up to 30 years old
18,000 miles of A zones (no BFEs) defined by various methods
 Floodprone soils
 Single cross section
Hurricane Alley Reopened
 Quick2
 Judgment
Detailed study topographic data
 2’ contours in cities
 10’ contours in piedmont/coast
 20’-40’ contours in mountains
Minimal digital data
Vector based maps
State-wide Tropical Connection
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Hurricanes Frances and Ivan Shifted Focus West
(1916, 1940 and 2004)
Piedmont Impacted 2006 (TS Alberto)
Plus nor’easters, thunderstorm, snow melt, flash
floods, urban flooding, dam failures…
Map / Data Limitations Revealed
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Age of State’s FIRMs
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FEMA’s mapping budget is finite
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75% at least 5 years old
55% at least 10 years old
North Carolina receives on average one updated
Flood Study for one county per year
Due to cost constraints, only 10-25% of flood
hazards in county are evaluated
Many up-to-date maps are using 15-20 year old
H&H studies
Time for processing proposed FIRMs / H&H studies is 1 ½
to 5 years
Many counties and communities lack resources to take on
map maintenance responsibility
FMP Program Objectives and
Deliverables
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New / up-to-date / improved Flood Insurance Rate Maps:
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Study on a Basin by Basin
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Issued on a Countywide Basis
New state-wise detailed, accurate elevation data
Hillshaded Relief of North Carolina
Statewide LiDAR Derived Elevation
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Reduction of time needed for post-preliminary review and appeals
process for new FIRM maps (6 months)
Better notification and dissemination of information about new and
revised maps being provided to state and local governments,
insurance agents, and citizens
FMP Program Objectives and
Deliverables - continued
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On-going program for updating and maintaining FIRMs
Better equipped and informed post-event mitigation
activities as a result of updated flood risk maps
Cost-effective data sharing through the implementation
and operation of an inter-operable Geographic
Information System
Internet web application providing cost-effective upload,
download, management, and dissemination of digital data
and maps (24 x 7 / free access)
Implement a real-time flood inundation and forecast
mapping system (flood warning)
Organization
NCEM
GTM Office
NCEM GIS
Floodplain
Mapping
Program
NCEM IT
FIMAN
NFIP
LOMC
FMP Current Status
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10,000 preliminary FIRMs issued / 97 counties /
63 co. with effective maps
30,000 stream miles analyzed and quality
controlled
Approximate Zone A areas replaced with Zone AE with
BFEs and cross sections
Over 300 “Scoping – Mapping Needs Assessment”
meetings (Initial and Final)
Completion of 17 River Basin Plans defining the streams
and scope of studies
100 Preliminary FIRM meetings and 105 Public FIRM
Outreach meetings
Certified Floodplain Surveyor (CFS) Program in its 6th
year (Demonstration State)
Will be Issued by
this time next month
As of
In Blue
Since November shaded Green
FMP Current Status…continued
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Received federal delegation to process, issue and
map LOMCs (MT-2) – 73 Issued
Memorandum of Agreement with NC DOT for NoRises and CLOMR / LOMRs
ADCIRC modeling and analysis for NC coastline to
determine new still water elevations (anticipated
completion by late Summer 2008)
Acquired, through 50/50 partnership with counties, highresolution imagery for eight counties in map maintenance
as of 2007
24 by 7 www.ncfloodmaps.com mapping viewer
Continue to develop Issue Papers (~ 60 Issue Papers and
20 Fact Sheets available to aid other state programs,
community officials and the public)
29 Counties in map maintenance - both state and
federal funding
FMP Funding
Past
 $136 million 2001-07
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2001 - 2007
$60.6 million
from FEMA
State & FEMA
2007 - Maintenance
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State – $2.4 million match
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FEMA – $11.737 million
$68.12 million
from State
Future
 State – Fee-based Oct 1, 2008
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FEMA – Map Maintenance from State 25%
match
FMP Delegation
LOMC Delegation
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FEMA Delegation
June 2006
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Status of Cases
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112 Received
68 Issued
2 Dropped
3 Withdrawn
LOMC Delegation
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NC DOT MOA – June 2008
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DOT 100% NFIP Compliant in NC
Monthly Working Meetings
FMP Reviews No-Rises
FMP Assist with LOMR Production
NC DOT Provides Funding Offset for Map
Maintenance
NC EEP
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Training / Working Meetings
MOA
FIMAN – Flood Warning
FIMAN – Flood Warning
Future Changes of NCFMP
“Post 1st Pass-Thru”
Phase 2 Vision
 Concept: Enhance and integrate risk
identification, risk communication, and risk
mitigation into the flood mapping program
 Guidance: FEMA’s Risk MAP Strategy
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FEMA Concept Paper: FEMA’s Flood Map
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FEMA’s Risk Draft Strategy: FEMA’s Risk Map
Modernization – Preparing for FY09 and Beyond:
Integrated Flood Data Update, Risk Assessment, and
Mitigation Planning – June 1, 2007
Strategy Integrating Mapping, Assessment, and
Mitigation Planning – February 20, 2008
NCFMP 2008+ Vision
 Key
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Base Activities:
Maintain hazard data derived from statewide remapping
Develop new data, applications, and protocols to
communicate, define risk, and mitigate against risk at the
local level
Move to a completely digital program
Obtain full delegation of mapping responsibility from FEMA
NCFMP 2008+ Vision
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Expand from the one-dimension of flood hazard
identification
Develop data and tools to enable communities
to estimate flood risks on a routine basis
Provide a means to communicate these risks to
the decision makers, stakeholders, homeowners
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What are your hazards?
What are your vulnerabilities?
How do you define risk?
Use this information to drive decision making
and mitigation efforts
2nd Phase – Modifications to Scope
 Flood
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Risk Identification Enhancements
Upgrade Current Geodatabase Design to Include:
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Develop 3D water surfaces
Create multiple return periods
Residual risk data
Add future development conditions
Document actual flood events (HWMs and rainfall depths)
Merge non-flood hazards (Wind, Fire, Landslide, Erosion)
Develop depth profiles
Depth of Flooding
Depth of Flooding
with Floodway
2nd Phase – Expansion of Scope
 Other
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Guidance from NFIP Reform Bill and NC Hazard
Mitigation Plan
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Hazard Risk Identification
High Winds (Hurricanes, Tornadoes)
Snow / Ice
Wildfire (Urban Interface)
Drought
Landslide
Earthquake
Dams (Residual and Break Risk)
Levees
Coastal Erosion
Integrate into Geodatabase with Flood Risk
Expansion to Flood Risk Analysis
Even if we know where the flood hazards are, do we
know who & what is at risk?
Goal:
To enhance the floodplain mapping program so that
it:
1.
Serves the traditional needs – insurance and
floodplain management
2.
Also provides risk information that supports
proactive mitigation
Depth of Flooding
Above BFE (ft)
Overlay flood hazards onto the built environment
Depth of Flooding
Above BFE (ft)
Flood Risk Analysis
4
3
2
1
0
1
Damage ($)
4
3
2
1
0
-1
0.005
0.01
0.2
Likelihood of
Occurrence
• Average annual damages
Calculate
• Total damages over a 30 yr.
mortgage
• Other
0.1
2nd Phase - Scope of Work
 Flood
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Develop tools to link the new geodatabase data to
risk identification
Digital Data Delivery Plan
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Risk Communication
Reduce demand for hardcopy products
Automated strategy to notify affected property owners of
SFHA changes
Test flood risk strategies and tools with 4 pilot
counties (Edgecombe, Pitt, New Hanover,
Buncombe)
Plan for upgrades to FMIS
2nd Phase – Risk Communication
2nd Phase - Scope of Work
 Flood
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Risk Mitigation
Review and modify flood hazard mapping
process to encompass mitigation activities
Evaluate relationships between State and
FEMA programs to flood risk initiatives
Develop integrated toolboxes for mitigating
risks for existing and future development
Visit the State’s Web Site:
www.ncfloodmaps.com
Questions?
Kenneth W. Ashe, P.E., CFM
kashe@ncem.org
(919) 715-5711 ext 105