Alabama Flood Map Changes - Gulf of Mexico Coastal Training

Report
Changes to Alabama Flood Maps
Impacts to Flood Insurance
Presented By:
Leslie A. Durham, P.E.
ADECA Office of Water Resources
January 23, 2014
1
Impacts of Flood Events
Flooding is not just a coastal concern….
Coastal Flooding
Riverine Flooding2
Why Update Flood Maps?
Need for new flood maps due to:
 Growth
 Development
 Urbanization
 Better delineation of Base Flood
Elevations:
 Advances in technology
 New elevation data
 Updated flood studies

Before
Map
Update
Risk
Map
3
Benefits of Map Changes
Better risk identification and accuracy help
property owners make more informed decisions!
Risk
Identify
Accuracy
Informed Decisions
4
Impacts of Map Changes
‘Mapped In’




Flood risk increased
Mandatory purchase of
flood insurance
Insurance costs may rise
to reflect true risk
Savings options:
 PRP Extension
 Grandfathering
‘Mapped Out’



Flood risk reduced, but
not eliminated
Flood insurance is
optional, but
recommended
Convert to low-cost
Preferred Risk
coverage
5
Implementing Map Changes
Lender
Agent
Property
Owner
Making it all work together….
Property owner has a 45-day period to
work with his insurance agent to
produce a standard flood insurance
policy – that most times is significantly
less expensive than force placed policies
6
Alabama Flood Map Updates

FEMA’s Map Modernization Program





OWR digitally updated all 67 counties
Mapped over 43,000 miles of floodplain
Model based Zone As with elevations
Changed scheme from a community
based map into a countywide FIRM
Wheeler Lake Guntersville Lake
Locust Fork
Middle Coosa
Upper Black Warrior
FEMA’s Risk MAP Program



Cahaba
13 watershed-based projects
Increased focus on identifying and
communicating flood risk
Encouraging mitigation actions to reduce
flood risk
Upper Alabama
Upper Choctawhatchee
Houston County
Mobile - Tensaw
Perdido
Mobile Bay
Perdido Bay
7
Mobile County Update

Detailed Studies – Zone AE
 570 miles of detailed study
 35 miles of “updated” detailed
studies

Approximate Studies – Zone A
 47 miles of “updated” approximate
study
 202 miles of new approximate
study

Coastal Studies
 100 miles of detailed coastal
studies
8
Baldwin County Update

Detailed Studies – Zone AE
 191 miles of detailed study
 38 miles of “updated” detailed
studies
 55 miles of new detailed studies

Approximate Studies – Zone A
 442 miles of “updated”
approximate study

Coastal Studies
 111 miles of detailed coastal
studies
9
Why Update Coastal Maps?



Effective Studies are out of date
4 to 6 feet BFE difference
Baldwin County Flood Insurance
Study
 Surge Elevations Revised 1983
 Wave Elevations Revised June 2002

Mobile County Flood Insurance Study
 Surge & Wave Elevations Revised
1983
Coastal Hazard Analysis
Coastal BFE on FIRMS include:




Storm Surge Stillwater elevation (SWEL)
Amount of wave setup
Wave height above SWEL
Wave run-up above SWEL (if applicable;
occurs at dunes, structures, cliffs etc)
Determined from
storm surge model
Two Phased Approach
Still Water Elevation + Wave Height = Coastal BFE
 Phase I (NWFWMD)
 ADCIRC/Wave Setup
 Storm Surge Modeling
Still
Water
Elevation
Coastal
BFE
Still Water Elevation
 Phase II (AL OWR)
 Overland Wave Modeling
Wave Height
Wave
Height
What is Coastal Storm Surge?
Phase I determines Still Water Elevation (SWEL) above Normal Tide
Phase I Model Components:


ADCIRC Modeling
Validation Storm Selection


Major storms with data
Synthetic Storm Simulation

JPM-OS – models the effects and
probabilities of simulated storms
Coastal Hazard Analysis
Phase II is the analysis to determine wave action on FIRMs



Modeling Setup
 Transect Layout
 Field Reconnaissance
 Obstruction carding
 Primary frontal dune delineation
WHAFIS Modeling
 Wave Height Analysis for Flood Insurance Studies
 Combines wave heights over land and SWEL at
each transect to produce combined elevations
Wave run-up analysis
 Maximum vertical extent of waves on a coastal
feature (dune, structure, cliff, etc.)
 Combined with WHAFIS results to predict BFEs at
each transect (higher elevation = BFE)
Scheduling Update
 Storm Surge Modeling Complete: January 16, 2014
 Overland Wave Analysis (Transect Modeling): July 2014






Coastal and Riverine Mapping: January 2015
Flood Risk Review/Resilience Meetings: June 2015
Preliminary Maps: July 2015
Post DFIRM meeting/Open Houses: August 2015
Public Comment: Winter 2015
Effective Maps: Summer 2016
Coastal Outreach Plan

Who?






Community Floodplain Mangers
Local Community Officials
Industry #1 – Developers, Engineers, and Builders
Industry #2 – Real Estate, Insurance, and Lenders
General Public
Media

How?

When?
 Informational Brochures specific to target audience
 www.southeastcoastalmaps.com
 www.adeca.alabama.gov/floods






Scoping
Modeling Phase
Map Production Phase
Preliminary Maps
Effective Maps
What Message?
 Customized status update for each County for each phase of the study process
 Why is the flood update important to me? (industries and general public)
 How can I participate?
Take Away for Property Owners
Flood Risk Changes Over Time– Become Flood Aware

Get an Elevation Certificate


Work with Insurance Agent to determine correct rating and policy




You do have options!
Inquire about cost saving options
Understand your policy
Take action to reduce your risk




Make sure your home is rated at the correct elevation
Elevate heating and cooling units
Install flood vents or break-away walls
Inquire with local officials about mitigation opportunities
Educate yourself about flood risk and changes in your floodplain



Property improvements should take new flood risk into consideration,
not just rely on old effective flood map
If located just outside of mapped floodplain, consider PRP policy
www.floodsmart.gov
Cost Saving Options
 Preferred Risk Eligibility Extension




Addresses the financial burden of mandatory
purchase requirements for policy holders in
newly mapped areas
Preferred Risk Policy (PRP) coverage has been
extended to include any building newly mapped
into floodplain after October 1, 2008
 Property must meet eligibility requirements
 Up to 2 years coverage under this rate
Annual increases under Biggert Waters
Grandfathering


Allows premium benefits after changes in map
zones or compliance standards
 Current flood insurance policy
 Built in compliance with previous FIRM
Potential Biggert Waters impacts
18
Take Away for Communities
Flood Map Changes are coming….Prepare now


Consider joining CRS or increasing your activities
Identify and apply for FEMA grants for flood mitigation
projects


Stay current on project status





Be involved in the process
www.southeastcoastalmaps.com
www.adeca.alabama.gov/floods
Alabama Flood Risk Information System (AL FRIS)
Consider increasing freeboard amounts in ordinance


Only 1 flood mitigation grant application statewide in 2013
Some areas will see increases based on preliminary storm surge results
Be proactive about identifying property that could be
impacted by new studies
Current Freeboard
County
Community
No. of NFIP Policies
NFIP Freeboard
Requirement* (feet
above BFE)
Baldwin
Baldwin County
10,098
3’ – only for assigned panel
numbers
Daphne, City of
420
1’ – All
Fairhope, City of
279
1’ – All
Gulf Shores, City of
7,571
3’ – V, VE (only)
Orange Beach, City of
9,746
2’ – A, AE, AH
3’ – V, VE
Bayou La Batre, City of
239
2’ - All
Dauphin Island, Town of
1,707
2’ - All
Mobile County
2,111
Mobile, City of
4,290
Saraland, City of
402
Mobile
2’ - All
1’ - All
1’ - All
Contact Info
Leslie Durham, PE
Chief, Floodplain Management Unit
ADECA Office of Water Resources
[email protected]
334-242-5506

similar documents