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Planning for the Future Now.  Make the Most of Built and Natural infrastructure.

SAME December 7, 2021

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Is the rate of projected climate change likely to be faster than your adaptive capacity?

JBLE-Langley

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JBLE-Langley

Adaptive Challenges

Adaptive Leaders

Adaptive Capacity

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JBLE-Langley

Stern, 2007

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Adaptation is a Cycle

  • Non-stationarity makes predict-then-act ineffective
  • Scenario based approaches better define robust Courses of Action (COA)
    • Highly dependent on risk tolerance
    • Representative Concentration Pathway (RCP) 2.6, 4.5, 8.5 are not predictions. They are points on trajectories of environmental change that are used for exposure, vulnerability, and risk assessment.
    • Scenarios are not deterministic or probabilistic but attempts to bound uncertainties about the future.

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JBLE-Langley

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���How Do We Efficiently Increase Our Adaptive Capacity in Changing Conditions?

  • What do we have?
  • What is working currently?
  • What do we expect to happen?
  • What is vulnerable in the future?
  • What do we need to protect?
  • What additional risks are being created in the future?
  • How do I embed climate-focused decision analysis into all processes?

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JBLE-Langley

DOD is a recognized leader in Adaptation

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2019-2020 Climate Change Impact Study

Contract:

  • Project No. MUHJ 19-0333, FFP Awarded 8/19/19

Sea Level Rise (SLR) Greatest Challenge:

  • Multiple climate hazards were modeled during the vulnerability assessment including, storm surge, rainfall, and SLR.
  • Moderate RCP 4.5 outcomes or events within the past 10 years were considered during development of modeling input.
  • VA Institute of Marine Science projected 1-1.7 foot (ft) increase in SLR over the next 50 years will exacerbate the current tidal nuisance (Blue Sky) flooding and is the most persistent and challenging impact forecasted.
  • Proposed Best Management Practices (BMPs) and ultimately the COAs were developed to combat the impact of a 1 ft SLR.

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Climate Change Impact Study Conclusions. Over the next 10-year horizon, the mission can be enhanced with the adaptive design and installation of 2 Gates and 5 Walls as well as routine rehabilitation and maintenance of the existing stormwater management system. Innovative, strategic planting of native, salt-tolerant species can be done opportunistically as components of future construction activities.

Original Study

OBJECTIVE - Identify vulnerable assets on JBLE-Langley and evaluate alternatives to enhance their resilience over the next 10 years.

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The Water is Here

  • JBLE-Langley has experienced sustained damage from six separate events over the last 10 years
  • Events have resulted in $52M in infrastructure and equipment damage, 210 hours of airfield operations loss, and 168 hours of non-essential personnel downtime
  • Largest storm-related cost impact not included in the 10-year total was $146M from Hurricane Isabel in 2003
  • From 2003 to 2011, JBLE-Langley experienced three storms with surge exceeding 7.5 ft

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JBLE-Langley

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JBLE – Langley Features

  • Located alongside Chesapeake Bay, adjacent to Newport News and Hampton, VA
  • Over the past 100 years, one of the largest changes of sea level in the world was a 1.45 ft rise measured in Sewell’s Point Tidal Gauge Norfolk, VA
  • Accelerating to 1 inch rise every 4 years
  • The entire base lies within 100-yr floodplain

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JBLE-Langley

Hampton, VA is second only to New Orleans, LA in its potential to experience impacts from flooding

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100- and 500-Year Floodplains

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Surrounded by Water

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Land Use – Space is Tight

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Cultural and Ecological Value

  • Oldest continually operating AFB in the world and the first military base focused on air power
  • Original buildings constructed on base were designed by one of the foremost architects at the time, Albert Kahn – many in National Register of Historic Places
  • Nine miles of shoreline and over 600 acres of tidally influenced wetlands
  • Marsh forests impacted by saltwater intrusion creating ghost forests and fire hazard

JBLE-Langley

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Community Impact

  • Annual economic impact to the community is $2.9 B, 20,497 military and civilian jobs
  • Surrounding communities are historic, disadvantaged, and economically reliant on the Base
  • All are susceptible to multiple forces of water, including SLR, storm surge, tidal action, stormwater, and groundwater, and are highly exposed to hazards such as hurricanes and nor-easters

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JBLE-Langley

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Inventory and Visualization

  • Inventoried all JBLE-Langley built and natural assets
  • Collected pertinent NOAA, NASA, AFCEC, FEMA, and USGS data
  • Interviewed base personnel and itemized preventative actions and the cost impact of previous storm events
  • Researched local weather and tidal patterns accounting for their changing nature
  • Compiled local off-base stormwater management plans to assess their impact on JBLE-Langley
  • Visualized all data on ArcGIS platform compatible with JBLE-Langley GeoBase

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Climate Change Study

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Existing BMPs and Functioning Outfalls

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Courses of Action - BMP Development

  • USACE HEC-RAS 2D model unsteady state model.
    • Calibrated with water surface elevation predicted during Hurricane Irene in 2011 by the NASA Tool
  • Model Inputs
    • Elevation data - 2012 Base LIDAR and Regional LIDAR
    • Rainfall Data obtained from NOAA Atlas-14
      • Data was increased by 20% to account for local, observed increases
      • Rainfall totals were distributed at 6 min intervals based on a Type II rainfall distribution
    • Tidal/Surge data was obtained from NOAA’s Sewell’s Point VA Station
      • Data was extracted at hourly time intervals using the NAVD88 ft datum

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Modeling

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Based on observed flow patterns, JBLE-Langley was divided into five (5) Hydraulic Management Unit (HMUs) for analysis of modeling results

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Baseline Modeling Scenarios

  • Modeled numerous short- and long-term scenarios
  • All scenarios included existing stormwater controls on the Base
    • Surface drains, culverts, outfall devices (accounting for present functionality e.g. submerged or free flowing), BMPs, living shoreline, and sea wall
  • Existing Tidal Influenced Flooding, maximum tidal wave height measured during the past 10 years was used for modeling.
    • Existing Tidal Influenced Flooding coupled with Rain Events (2 year, 100 year and 500 year)
  • Future Tidal Influenced flooding accounting for a SLR of 1 ft above the current 10 year maximum value.
    • SLR coupled with Rain Events (2 year, 100 year and 500 year)
  • Extreme Weather Flooding
    • Storm Surge (Based on Hurricane Irene 2011, 8 ft)
    • Storm Surge coupled with Rain Events (2 year, 100 year, 500 year)

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Modeling

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Courses of Action - Adaption Modeling Scenarios

  • Involves analyzing baseline scenario results and identifying vulnerable/flood prone areas within each HMU
  • Develop flood mitigation measures, BMPs, to address vulnerable/flood prone areas
  • Mitigation measures (BMPs) were selected based on modeling results of the Future SLR Tidal Influenced flooding
  • Proposed adaption measures can be applied to extreme weather with an adjustment in height and elevation
  • Model with BMPs in place to access their suitability/efficiency and apply to all Baseline Modeling Scenarios
  • BMPs selected based on the principles of block, divert, store, and pump
  • BMPs not designed to address direct rainfall on Base as this is currently being handled by existing stormwater infrastructure

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Modeling

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Facilitated Focused Dialogue and Ranking

  • Facilitated the installation stakeholders in three distinct ranking exercises within and across HMU’s to identify and build consensus for the preferred BMPs
    • Efficacy
    • Implementability
    • Overall Preference

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Facilitation

“Nobody is as wise as we altogether“ – African Proverb

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Scenario

Analysis

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Climate Change Study Conclusions

  • Over the next 10-year horizon, the mission of JBLE-Langley can be enhanced with the adaptive design and installation of 2 Gates and 5 Walls as well as routine rehabilitation and maintenance of the existing stormwater management system.
  • Innovative, strategic planting of native, salt-tolerant species can be done opportunistically as components of future construction activities

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Climate Change Study

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2021 Repair Base Stormwater BMPs Design Contract

Contract:

  • Project No. MUHJ 20-4080, FFP Awarded 7/29/21 – 12/6/22

Build Upon Previous Study:

  • All design elements will be evaluated against the updated USACE HEC-RAS model utilized in the original Climate Impact Study.
  • All scenario base assumptions used in the Climate Study for rainfall, storm surge, and SLR will be maintained through this design effort to assure that the design of BMPs will provide the most desirable outcome in terms of flood reduction.

Project Kickoff Initiates Data Gathering Effort will include field investigations to support geotechnical design. Design scope includes 65, 90, and 100% packages.

Design Award

Current Status – GeoTechnical field investigation is complete and 65% design initiated.

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GeoTechnical Investigation

Summary of Exploration

  • Wall 1:
    • One CPTu, 75ft depth – dissipation at 25ft, 50ft, 75ft
    • One SCPTu, 41.6 depth – dissipation at 25ft, 41.6ft
  • Wall 2:
    • One CPTu, 50ft depth – dissipation at 25ft, 50ft
    • One SCPTu, 75ft depth – dissipation at 25ft, 50ft, 75ft
    • One Macro-Core location, two samples in the top 15ft bgs
  • Wall 3:
    • One CPTu 50ft depth – dissipation at 25ft, 50ft
    • One Macro-Core location, one sample in the top 15ft bgs
  • Wall 4:
    • Two CPTu, 50ft depth – dissipation at 25ft, 50ft
    • One SCPTu 50ft depth – dissipation at 25ft, 50ft
    • One Macro-Core location, two samples in the top 15ft bgs
  • Wall 5:
    • One CPTu, 50ft depth – dissipation at 25ft, 50ft
    • One SCPTu, 50ft depth – dissipation at 25ft, 50ft

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GeoTechnical Investigation

Example of a Typical CPTu Log

Strata Encountered at JBLE Langley

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Stratum I: Fill , SBT=“Sands”

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Stratum II:�Tabb Formation , SBT=“Clays” or “Silt Mixtures”, Expected to be Clayey Sands (SC)

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Stratum III (not always observed):�Yorktown Formation , SBT=“Sands” or “Sand Mixtures”, Expected to be Silty Sands (SM) with High Amount of Shell Fragments decreasing with depth

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Stratum IV:�Yorktown Formation , SBT=“Sands” or “Sand Mixtures”, Expected to be Silty Sands (SM), with less shell fragments than Stratum III

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Stratum V (not always observed): �Yorktown Formation , SBT= mainly “Silt Mixtures” expected to be Clayey Sands (SC)

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Groundwater vs Tides

Newmarket Creek (USGS)

Sewell's Point

(NOAA)

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GeoTechnical Investigation

  • Characterized the top 15 ft at each wall location using CPT, SCPTu, and Macro-Core.
  • Groundwater was observed at depths which were variable from 1.3 ft to 5 ft bgs and was observed to be influenced by the tides.

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GeoTechnical Investigation

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COA Design vs Development – Space is Tight

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Climate-Focused Decision Analysis - Integration Across Teams

  • Develop Comprehensive Basewide Strategy
  • Embed Climate Change Facilitators across multidisciplinary teams
    • Support translation of global climate change data to local conditions
    • Support communication within/across teams and with public – Public Relations is essential
    • Identify opportunities to enhance construction efforts with BMP features to extend their functionality

Implementation

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Don’t Forget Your Natural and Nature-Based Infrastructure

  • Maximize sustainable solutions
  • Basewide Strategical Planting Plans
  • Expand wetlands when possible
  • Utilize living shorelines
  • Maximize stormwater credits

Implementation

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For more info, visit NuGlobalSolutions.com �or contact:

Kandi Brown, CC-P �kbrown@nf-gov.com | 865-789-5435 

Daphne Williams �ddwilliams@nf-gov.com | 864-346-3145 

THANK YOU