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?

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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

Response: Louisiana’s Comprehensive Master Plan for a Sustainable Coast

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The Plan Builds on Other Efforts

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2012 Master Plan Update Provides New Elements

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• 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

Seven Predictive Models

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2012 Master Plan Development

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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…

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Identifying Projects

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• 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

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• 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

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• 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

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• 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

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1. First, establish risk reduction targets2. Identify project areas and attributes3. Develop conceptual projects4. Evaluate the projects and scenarios

Evaluation of Nonstructural Projects

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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

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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

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• 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

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Elevated Residential House Being Constructed in Gentilly, Build Now NOLA

Progress towards Risk Reduction Target

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EAD Reduction vs. Project Cost

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• 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

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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:

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• 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:

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• 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:

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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?

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www.coastalmasterplan.la.gov

Questions

Michèle Deshotels, Coastal Resource ScientistCoastal Protection and Restoration Authoritymichele.deshotels@la.gov (225) 342-3051

Harold E. Clarkson, PE, CFMBrown and Caldwellhclarkson@brwncald.com (803) 873-9708