Planning for Impacts of Sea Level Rise on Coastal Infrastructure

Moderator Zack Steele- Wells National Estuarine Research Reserve
Presenters Paul Kirshen –Battelle Memorial Institute
Samuel Merrill – University of Southern Maine

-Apply Science to make better decisions

Old Orchard Beach, Maine Case Study

• www.oobmaine.com
• Businesses at rise; 1/3 at risk during hurricane season
  
• Mitigation and Adaptation
• Payback time
• IEC sea level rise modeling company
• Storm surge and sea level rise
• Property values
• Can look into the future at probability of damage
• Graphs showing investment
• How to share the information?
• Outreach vehicle

Topics

• Impacts of Climate Change
• Infrastructure
• Ecosystems
• Environmental Justice Communities
• Scenario-Based Risk Assessment Approach to Adaptation Planning
• Example Application to Coastal Storm Surge Planning

Future Sea Level Rise

• 2007 estimation
• 50cm-140cm by 2100
• Greenhouse gases change
• Uncertainty in program
• Local effects
• Changes in frequency of current “100 year storm” events,
• Ecosystem services
• Ex. Loss of wetland, won’t be able to absorb storm surge
• Lower income communities will see higher damages vice versa (not publishable information)

Adaptation Strategies

Reactive-wait until impacts have occurred
Proactive-take actions before major impacts have occurred, shown to be more cost effective

• Do nothing
• Protection-attempts to manage the hazard with hard structures such as seawalls and groins or soft measures such as beach nourishment
• Accommodation elevate buildings or retreat

Natural Environment Adaptation Actions

• Keep natural environment healthy

Proactive Adaptation Design Challenges include:

• Need to consider climate change in planning now so proper adaptation can occur
• When to invest in adaptation?
• Other driving forces on infrastructure
• Unknown future GHG levels and mitigation acheived
• Stakeholder Involvement at all levels is Critical
• Interactions with other infrastructure sectors and the environment

Way Forward for Design

• Use Principles of Integrated Coastal Zone Management
• Adaptive Management
• Life Cycle Analysis
• Use of Co-Benefits
• Precautionary Approach
• Plan for the worst
• Take action now
• Big in Europe
• Robust Solutions (work over range of outcomes)
• Risk-based Scenario Analysis

Scenario-Based Risk Assessment

• Consideration of system performance over all conditions, moves away from traditional design event approach
• Explicitly recognizes that uncertainty (lack of quantified probabilities) exists in the process and must be addressed through scenario analysis
• Relies upon two way communication with stakeholders-adaptation is local action
• “Safe to Fail, not Fail Safe”
• Most cost effective way of planning

Application to SLR Impacts in Old Orchard Beach

• Determine areas vulnerable to SLR permanent flooding and storm surge flooding for 2100 SLR2 of 50, 100, 150 cm
• Determine Expected Value of Damage to Building so 2010 and 2100 under SLR scenarios
• Use above values to estimated expected values of impacts 2010 or 2100
• Discuss adaptation action with OOB and Southern Maine RPC

Possible Adaptation Options

• Dune construction and beach nourishment
• More tide gates
• Reconfigure existing beach access
• Increase required building elevation above the flood plane
• Regional approach

Next steps

• Refine method with OOB including benefits and costs of various adaptation options under various scenarios

Q-Question, A-Answer R-Response to communication question by presenters

Q: Is this modeling only applied to Old Orchard Beach
A: Work in the process

Q: Explain Co-Benefits further
Co-Benefits are actions that not only help adaptation but also have non climate related benefits. There are also no regrets actions which are beneficial today and tomorrow regardless of changes in sea level.

Q: Everything seems too uncertain. Put money somewhere else.

A: Climate Change I don’t do that research. Researchers say 50-150, I believe them.

Q: Are the specific actions up to the communities?

A: Believes will be driven by communities, money from government

Q: Meeting in Italy 80% reduction of 1990 by 2050, 2 C degree, where do these numbers come from?

A: Scientists have said these are the numbers that can not be exceeded without dire effects.

Q: Communication, tide gates won’t be allowed in Maine

A: Adaptation strategies are not based on current political regulations

Q: Isostatic rebound, some land is going up does the modeling take this into consideration?

A: Rebound is occurring in Canada; In Maine we are going down.

R: Local Level, so how we gonna pay? Federal money is not there for adaptation or mitigation, replacement structures to move is not supported financially

R: Tax impact calculator, Mill Rate

R: Whose costs are they going to be

R: Real damage, 3-D maps

R: Look at political and social effects

R: Full cost accounting

R: 100 year flood that happens in 5 years? How is that possible, what is it?

R: Adaptation, level of confidence, jetties and breakwaters, I thought they were already proven as not working

R: 3-D something that we recognize. You don’t speak English, and you don’t draw things that we see, things will make sense, dollars are dollars, I understand it but could not communicate what I learned today,

R: Relate to historic storms like the Patriots day storm, so we know what we are dealing with