consulting engineers and scientists

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1 consulting engineers and scientists Flood Resiliency Planning with Modeling of Potential Cumulative Damages Naval Station Mayport with 5 of sea level rise SAME Savannah Post Technical Sessions Jonathan T. Lockman, AICP February 23, 2017

2 Session Overview GEI background Sea level rise and extreme weather Modeling of cumulative flooding damages GEI s COAST tool Benefit-cost analysis for investments to protect assets Portsmouth Naval Shipyard example Discussion

3 GEI Background Founded in 1970 Headquarters in Boston Geotechnical Roots Environmental & Water Resources 760+ Employees 37 Offices 56,000+ Projects in all 50 states and 25 countries Knoxville, Raleigh, Atlanta & West Palm Beach Southeast Locations

4 Disciplines and Service Areas Environmental Compliance Permitting Due Diligence Characterization Remediation Risk Assessment Restoration Asbestos Demolition Brownfields In-Water & Uplands Geotechnical Coastal Engineering & Planning Foundations & Excavation Support Construction Tunneling Dams Embankments Levees Failure Analysis Water Resources Conveyance Flood Control Water Management Water Supply and Storage Water Resources Support Hydropower Ecological Ecotoxicology Monitoring Water Quality Aquatic Ecosystems Environmental Impact Laboratory Services Sensory Services Air Quality Ecological Geotechnical Testing

5 Goldman Sachs Building, Jersey City, NJ Flood Modeling Paired With Engineering & Design Solutions

6 MassPORT Berths 9 and 10 Maritime Engineering at the Water s Edge

7 Need for Resiliency Planning

8 Sea Level Rise: Ft. Pulaski, Georgia

9 Rates of Sea Level Rise are Increasing Miami 667/ALTERNATES/FREE_960/miami%20beach%20flooding Since

10 More Frequent Heavy Rainfall (1% Events, )

11 Flood Frequency is Influenced by Sea Level Recurrence Interval Changes! Nuisance Flooding, Portland, ME, October 2011 at high tide (M. Craig)

12 Flood Frequency is Influenced by Sea Level Annapolis, MD

13 Coastal Sites Will Face Increasing Vulnerability from Sea Level Rise and Storm Surge Amount of sea level rise alone is not a problem here, but its link to more frequent surges with shorter recurrence intervals can be.

14 How Vulnerable Are We If We Do Nothing? Height of bars represents relative dollar damage to Buildings Processes Revenue streams E.g., 50-yr flood today = $140M in damages and lost revenue.

15 How Vulnerable Are We If We Do Nothing? Height of bars represents relative dollar damage to Buildings Processes Revenue streams E.g., 100-yr flood today = $350M in damages and lost revenue.

16 Vulnerability to Sea Level Rise or Surge Mayport Naval Station, Atlantic City, FL

17 Mayport Naval Station, present MHHW

18 Mayport Naval Station, +2 SLR or Surge This amount of sea level rise may take decades to happen, but a surge this size could arrive this season.

19 Mayport Naval Station, +3 SLR or Surge

20 Mayport Naval Station, +5 SLR or Surge

21 Vulnerability Assessments Most will list and prioritize vulnerable assets. Few describe specific actions with design threshold detail or compare which are the best investments. If they do, it s generally based on snapshots of future scenarios.

22 Current Approaches Are Mostly Snapshots 100-year event 2070 But what about all the other events?? The 10-year, 50-year, 250-year, or 500-year events? The changing base water levels from SLR in that period? Damages from all these events? 100-year event 2030 Costs to adapt are provided, but without accounting for damages or repetitive losses. Is it worth it? Determining how much to spend needs to consider all of this!

23 GEI s COAST Software

24 COAST is a means of Evaluating cumulative vulnerability to storm surge, sea level rise, and/or extreme runoff, versus snapshots. Tailored to specific engineered structures. Comparing costs and benefits of candidate adaptation actions or alternative designs.

25 Methods Apply to Many Vulnerable Assets Buildings and building contents Bridges, roads, and culverts Piers, wharves, other waterfront structures Wastewater treatment plants Oil refineries, industrial or energy production facilities Dams and levees

26 Some Project Sites Completed or Underway Selsey, United Kingdom Santos, Brazil Fort Lauderdale, Florida Key Largo, Florida Key West, Florida Islamorada, Florida South Miami, Florida Kingston, New York Piermont, New York Catskill, New York East Hampton, New York Groton/Mystic, Connecticut Fairfield, Connecticut Hampton, New Hampshire Hampton Falls, New Hampshire Newburyport, Massachusetts Marshfield, Massachusetts East Machias, Maine Falmouth, Maine Portland, Maine Bowdoinham, Maine Old Orchard Beach, Maine Scarborough, Maine Bath, Maine Farmington, Maine New Sharon, Maine Duluth & Rochester, Minnesota East Hampton, New York

27 Input: Depth Damage Functions (by Building Type) Percent damage, water elevation relative to FFE ACOE estimates are robust across construction types, use types, contents types, structural variations (basement or not), etc.

28 Input: Tailored Sea Level Rise Curves

29 Input: Flood Elevations & Recurrence Intervals

30 Input: Exceedance Curves Elevation Water Heights and Probabilities

31 Location-Specific Exceedance Curves Flood Height (ft. above MHHW) Return Period FEMA Exceedance Curve 1 FEMA Exceedance Curve 2 Each parcel has its own exceedance curve based on its location. Using multiple exceedance curves makes flood damage estimates more accurate.

32 COAST provides Snapshots and Cumulative Damage Estimates One time damage estimates for a particular storm event in the future (such as a 100-year storm arriving in the year 2050, with 30 inches of sea level rise). Cumulative damages from all possible events (such as the 10, 50, 100 or 500-year storms) during the period 2017 to 2050).

33 Community Protection Example Heights of Blue Bars Indicate Predicted Dollar Damages at Each Location Brown Areas Indicate Parcels Inundated by Sea Level Rise by 2050, Under the Medium Scenario Area 1 Wainscott/East Hampton Village Patterns of Damage from a Single 100-yr. Storm

34 Community Protection Example: Video Heights of Blue Bars Indicate Predicted Dollar Damages at Each Location Brown Areas Indicate Parcels Inundated by Sea Level Rise by 2050, Under the Medium Scenario Area 4 - Napeague Area 1 Wainscott/East Hampton Village Patterns of Damage from a Single 100-yr. Storm

35 Area 1: Cumulative Damage, STUDY AREA 1 Wainscott/East Hampton Village Medium Sea Level Rise 30 by 2080 Years Cumulative Damage Buildings Inundated by SLR Land Inundated by SLR Total Valuation Inundated by SLR $ 128,237,448 $ 10,457,627 $ 1,016,949 $ 11,474, $ 134,443,479 $ - $ 169,492 $ 169, $ 262,680,927 $ 10,457,627 $ 1,186,441 $ 11,644,068 High Sea Level Rise 58 by 2080, 72 by 2100 Years Cumulative Damage Buildings Inundated by SLR Land Inundated by SLR Total Valuation Inundated by SLR $ 141,633,942 $ 10,457,627 $ 1,186,441 $ 11,644, $ 182,812,253 $ 8,381,356 $ 1,330,509 $ 9,711, $ 144,560,011 $ 627,119 $ 932,203 $ 1,559, $ 469,006,206 $ 19,466,102 $ 3,449,153 $ 22,915,254 New York Rising Risk Area Total Valuation Moderate $ 538,727,589 High $ 496,388,983 $263 Million by 2080, with 30 of SLR Extreme $ 438,170,433 All $ 1,473,287,006

36 Adaptation Designs Benefit Cost Analysis Calculate: Ratios Indicate Efficiency Design 1: Buyouts Design 2: Elevate & Floodproof Design 3: Build a Flood wall Subject assets to a range of future conditions Avoided damages Construction costs plus repair costs and lost revenue 0.2:1 1:1 5:1

37 Approach for Military Sites: Vulnerability Assessment and BCA 1. Identify which assets need protection: piers, dry docks, building contents, utilities, etc. 2. Prioritize. 3. Inventory elevations of assets, including key openings and contents. 4. Prepare conceptual adaptation actions. a) to protect individual or multiple assets (e.g., elevation, flood-proofing, seawalls or bulkheads); or b) to relocate the assets. 5. Develop cost estimates for each action. 6. Conduct Benefit Cost Analyses (BCAs) to compare their effectiveness, in terms of cumulative avoided damage.

38 Portsmouth Naval Shipyard, Kittery, ME

39 Portsmouth Naval Shipyard, Kittery, ME

40 Portsmouth Naval Shipyard, Kittery, ME

41 DDFs tailored to structure & building contents Assumptions: Structure Value = $2 million Contents Value = $2 million Inventory height of openings and value of vulnerable building contents. Significant 6 foot water depth above grade, 5 foot depth in building, 39% damage to contents, 28% damage to structure. 2 foot water depth above grade, 1 foot depth in building, 12% damage to contents, 10% damage to structure. Water crests platform, reaches 1 foot depth above grade, 1% damage to contents, 0% damage to structure. No damage.

42 Mock Results: COAST Vulnerability Assessment Assumptions: Bldg. Structure Value: $2 million Contents Value: $2 million Flood Heights and Probabilities: FEMA Flood Insurance Study (Kittery, ME1984) DDFs: Army Corps of Engineers, NACCS (2015), Tables 35 & 37 Sea Level Rise (SLR): NYS DEC Projections (2017) By 2050: 30 inches - High 8 inches - Low Damage Estimates ($ thousands) One Time Damages from 100-yr. Storm in 2050 Cumulative Damages from 2016 to 2050 Damage Type High SLR (30 ) Low SLR (8 ) Building Structure Building Contents Building Structure Building Contents 220 2

43 Questions and Analysis of Mock Results Scenario for year 2050 why not longer? Should we have used FEMA s preliminary flood study? (BFE is 1.7 feet higher) Looking at groups of buildings vs. individual structures? To relocate, floodproof or elevate compare actions, relative efficiency When to take action? Low damages with sea level rise here, but what about other sites? Transferable? Mayport & Norfolk bases are different than Portsmouth topography and tidal differences.

44 Portsmouth Naval Shipyard

45 Naval Station Norfolk v. Portsmouth

46 Naval Station Mayport v. Portsmouth

47 Vulnerability Assessment and BCA Outcomes These analyses help ensure that design decisions are financially robust given an uncertain environmental future. Opportunity to protect structural assets at the lowest cost that will minimize odds of overbuilding or underbuilding. Figure out relative dangers from surge versus sea level rise interaction. Sometimes the less expensive actions can be the best investment, optimizing funds across portfolios of upgrades. Analyses can justify funding requests.

48 Flood Resiliency Planning with Modeling of Potential Cumulative Damages Thank You! Jonathan T. Lockman AICP: