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Large Scale Nonstructural Programs - Louisiana’s Comprehensive Master Plan for a Sustainable Coast – 2012 Update
Association of State Floodplain ManagersSan Antonio, TexasMay 22, 2012
• The problem is big, immediate and of national significance• 90% of nation’s outer continental
oil and gas• 20% of nation’s waterborne
commerce• 26% (by weight) of commercial
fisheries• 5 million migratory waterfowl’s
winter habitat
• The solution is first of its kind and comprehensive
• We can all learn from the process
Why Should We be Concerned with Louisiana?
2
Coastal Louisiana is Facing a Crisis – Land Loss
Over 1,800 square miles lost since the 1930’sOver 1,700 square miles lost in next 50 years
Coastal Louisiana is Facing a Crisis – Storm Damage
Storm Tracks in the Gulf of Mexico
Recent StormsKatrina (Aug 2005)Rita (Sept 2005)Gustav (Aug 2008)Ike (Sept 2008)
Future Risk (50 years) Estimated Annual Damages between $7.7B and $23.4B
Some communities targeted for 100 year protection could experience an increase of up to four feet of flooding in a 100 year event by Year 50 under the moderate scenario.
Gulf of Mexico - Historical Storm Tracks
2012 Master Plan Update Provides New Elements
7
• Detailed assessment of the future if we take no new action
• Expanded portfolio of solutions available to coastal residents through nonstructural protection measures
• Evaluation of hundreds of candidate project ideas
• Use of innovative tools to identify the best projects and the most effective use of dollars
• Large scale solutions that address the root causes of land loss and reduce flooding risk for coastal communities
• Additional guiding objective that reflects the importance
of Louisiana’s working coast
2012 Master Plan Development
9
Science & Engineering
Board (MP-SEB)
Framework Development Team (FDT)
Stakeholders
CPRACoastal Protection and Restoration Authority
Project Effects Models
Technical Advisory
Committee
Planning Tool Technical Advisory
Committee
Master Plan Senior
Decision Team
Master Plan Delivery Team
Modeling Workgroups
(7)
• Flood Protection: Reduce economic losses from storm surge…
• Natural Processes: Promote a sustainable coastal ecosystem…
• Coastal Habitats: Provide an array of habitats...
• Cultural Heritage: Sustain the unique cultural heritage…
• Working Coast: Promote a viable working coast …
Looking 50 Years Out…
10
Identifying Projects
11
• Developed projects from existing concept plans• 1500 projects reviewed• 418 projects evaluated• 145 projects in the draft plan
• Nonstructural concepts had to be developed
1. First, establish risk reduction targets2. Identify project areas and attributes3. Develop conceptual projects4. Evaluate the projects and scenarios
Evaluation of Nonstructural Projects
12
• Risk reduction targets established for each coastal community to guide investments
500-year protection100-year protection50-year protection
• Focus on economic losses due to flooding of built infrastructure and crops
Flood Risk Reduction Across the Coast
• Determine population density of census blocks• < 1,000 people per square mile = 50 year• > 1,000 people per square mile = consider
total population
• Expand census blocks to community limits
• Determine total population• < 3,500 people = 50 year
(rural parish area)• > 3,500 people and < 75,000 people = 100
year(urbanized area)
• > 75,000 people = 500 year(metropolitan area)
Risk Reduction Targets
14 No guarantee that the level of risk reduction will be achieved.
1. First, establish risk reduction targets2. Identify project areas and attributes3. Develop conceptual projects4. Evaluate the projects and scenarios
Evaluation of Nonstructural Projects
16
• Each Parish and Community across the coast• Projects are typically implemented at local level• Each parish and community can be broken down
into census blocks for evaluation
Project Areas
17
• Flood mitigation elevation (how high to floodproof or elevate and when to acquire)
• Structure classification• 4 classes of residential• 4 classes of nonresidential
• Participation rate• Project costs
• Unit cost by class, square footage, and elevation
• Duration of implementation• Uncertainty estimates on attributes
Nonstructural Project Attributes
18
1. First, establish risk reduction targets2. Identify project areas and attributes3. Develop conceptual projects4. Evaluate the projects and scenarios
Evaluation of Nonstructural Projects
19
FEMA Flood Depth
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Ground elevation from DEM Census Block Centroid
FEMA Base Flood Elevation (FBFE)Census Block Centroid
FEMA flood depth
NOTE: Base Flood Elevations obtained from current effective FEMA Flood Insurance Rate Maps
• Nonstructural projects consist of:• Nonresidential flood proofing (0 – 3 feet)• Residential flood proofing (0 – 3 feet)• Elevation of residential structures (3 – 18 feet)• Acquisition of residential structures (> 18 feet)
• Each project has two versions• Elevate homes to BFE + 1 feet• Elevate homes to BFE + 4 feet
Based on FEMA Flood Depth
21
Project Concept
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• One mitigation technique per census block
• Multiple census blocks per community
1. First, establish risk reduction targets2. Identify project areas and attributes3. Develop conceptual projects4. Evaluate the projects and scenarios
Evaluation of Nonstructural Projects
23
• Various landscape conditions• Wide range of possible storms (720
storms)• Surge and Wave models (ADCIRC):• Coastal Louisiana Risk Assessment
(CLARA) model
Models Used to Estimate Annual Damage
• Nonstructural implementation costs and residual damages calculated at census block level
• Reported for communities and parishes
• Nonstructural projects compared with other protection projects
• Which project or combination of projects achieves greatest progress towards target
Compare Results to Targets
25
Elevated Residential House Being Constructed in Gentilly, Build Now NOLA
• Programmatic measures not evaluated in planning tool, but included in Master Plan• Nonstructural program coordination
and communication• Regulatory actions• Funding and support initiatives• Education and training programs
Do not recreate the problem….
Nonstructural Programmatic Measures
30
Levee Failure in New Orleans, USACE
• High participation is critical for effective large scale nonstructural projects
• Large nonstructural projects can have profound impact on sense of community
• Care has to be taken to avoid environmental justice issues• More freeboard provides more protection, but not always necessary• Communication is critical and terminology is important
(nonstructural confusion & implications of protection)• More data is needed
• Costs (especially floodproofing)• Social impacts (especially for acquisition and relocation)• Effectiveness of programmatic measures• Impact on historic structures
• Local Hazard Mitigation Plans need more detail• You have to know where you want to go in order to draw a map of how to
get there….
Lessons Learned to Date:
31
• High participation is critical for effective large scale nonstructural projects
• Large nonstructural projects can have profound impact on sense of community
• Care has to be taken to avoid environmental justice issues• More freeboard provides more protection, but not always necessary• Communication is critical and terminology is important
(nonstructural confusion & implications of protection)• More data is needed
• Costs (especially floodproofing)• Social impacts (especially for acquisition and relocation)• Effectiveness of programmatic measures• Impact on historic structures
• Local Hazard Mitigation Plans need more detail• You have to know where you want to go in order to draw a map of how to
get there….
Lessons Learned to Date:
32
• High participation is critical for effective large scale nonstructural projects
• Large nonstructural projects can have profound impact on sense of community
• Care has to be taken to avoid environmental justice issues• More freeboard provides more protection, but not always necessary• Communication is critical and terminology is important
(nonstructural confusion & implications of protection)• More data is needed
• Costs (especially floodproofing)• Social impacts (especially for acquisition and relocation)• Effectiveness of programmatic measures• Impact on historic structures
• Local Hazard Mitigation Plans need more detail• You have to know where you want to go in order to draw a map of how to
get there….
Lessons Learned to Date:
33
• High participation is critical for effective large scale nonstructural projects
• Large nonstructural projects can have profound impact on sense of community
• Care has to be taken to avoid environmental justice issues• More freeboard provides more protection, but not always necessary• Communication is critical and terminology is important
(nonstructural confusion & implications of protection)• More data is needed
• Costs (especially floodproofing)• Social impacts (especially for acquisition and relocation)• Effectiveness of programmatic measures• Impact on historic structures
• Local Hazard Mitigation Plans need more detail• You have to know where you want to go in order to draw a map of how to
get there….
Lessons Learned to Date:
34
• High participation is critical for effective large scale nonstructural projects
• Large nonstructural projects can have profound impact on sense of community
• Care has to be taken to avoid environmental justice issues• More freeboard provides more protection, but not always necessary• Communication is critical and terminology is important
(nonstructural confusion & implications of protection)• More data is needed
• Costs (especially floodproofing)• Social impacts (especially for acquisition and relocation)• Effectiveness of programmatic measures• Impact on historic structures
• Local Hazard Mitigation Plans need more detail• You have to know where you want to go in order to draw a map of how to
get there….
Lessons Learned to Date:
35
• High participation is critical for effective large scale nonstructural projects
• Large nonstructural projects can have profound impact on sense of community
• Care has to be taken to avoid environmental justice issues• More freeboard provides more protection, but not always necessary• Communication is critical and terminology is important
(nonstructural confusion & implications of protection)• More data is needed
• Costs (especially floodproofing)• Social impacts (especially for acquisition and relocation)• Effectiveness of programmatic measures• Impact on historic structures
• Local Hazard Mitigation Plans need more detail• You have to know where you want to go in order to draw a map of how to
get there….
Lessons Learned to Date:
36
• High participation is critical for effective large scale nonstructural projects
• Large nonstructural projects can have profound impact on sense of community
• Care has to be taken to avoid environmental justice issues• More freeboard provides more protection, but not always necessary• Communication is critical and terminology is important
(nonstructural confusion & implications of protection)• More data is needed
• Costs (especially floodproofing)• Social impacts (especially for acquisition and relocation)• Effectiveness of programmatic measures• Impact on historic structures
• Local Hazard Mitigation Plans need more detail• You have to know where you want to go in order to draw a map of how to
get there….
Lessons Learned to Date:
37
Draft 2012 Master Plan TimelineEarly January: Draft 2012 Coastal
Master Plan posted on-line, hard copies available upon request
January 23 - 25: Public meeting February 25: Public comment period
endsMarch 21: Meeting of the Coastal
Protection and Restoration Authority to review and approve final plan
Early April: 2012 Master Plan submitted to Louisiana Legislature
Where is CPRA in the process?
38
www.coastalmasterplan.la.gov
Questions
Michèle Deshotels, Coastal Resource ScientistCoastal Protection and Restoration [email protected] (225) 342-3051
Harold E. Clarkson, PE, CFMBrown and [email protected] (803) 873-9708