CITY of VIRGINIA BEACH RESORT AREA STRATEGIC ACTION PLAN (RASAP) - - PDF document

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CITY of VIRGINIA BEACH RESORT AREA STRATEGIC ACTION PLAN (RASAP) - - PDF document

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CITY of VIRGINIA BEACH RESORT AREA STRATEGIC ACTION PLAN (RASAP) Steering Committee Agenda Monday, October 7th [2:00pm-4:30pm] AGENDA 2:00 City of Virginia Beach Sea Level Rise Study Brief - CJ Bodnar (20 minute presentation + 10 minute

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CITY of VIRGINIA BEACH

RESORT AREA STRATEGIC ACTION PLAN (RASAP) AGENDA City of Virginia Beach Sea Level Rise Study Brief - CJ Bodnar (20 minute presentation + 10 minute Q&A)

YARD & COMPANY

Kevin is a leader in community development, economic and real estate development fjnance, have included several public and private partners and a diverse set of public fjnancing tools such

RASAP Steering Committee - working session

  • Review & discuss individual edits to the draft
  • Form consensus around edits and revisions to text and graphics

Steering Committee Agenda Monday, October 7th [2:00pm-4:30pm] 2:00 Schedule/Next Steps 4:15 2:30

  • RASAP Steering Committee Meeting – Thursday, 11/07/19 – 10 :00 – 12:00 @ CVB Board Room
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Sea Level Wise

City of Virginia Beach Sea Level Rise Adaptation Study

City of Virginia Beach, RASAP Steering Committee

C.J. Bodnar, P.E. Public Works, Stormwater Engineering Center October 7, 2019

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Moody’s Questionnaire to VB (2014)

  • Does the existing/future CIP include spending

for mitigation or resiliency?

  • Has your governing body discussed the capital
  • r financial implications of rising sea levels?
  • Has there been an estimate on potential impacts

from rising sea levels or flooding?

  • Please discuss how flooding has impacted the city’s budget and how flood mitigation efforts may impact

future budgets?

  • Have there been any zoning /long-term planning adjustments downtown and along the waterfront to

mitigate future flooding impacts?

  • What is management’s current view on the potential impact/vulnerabilities in your community from rising

sea levels and a heightened risk of extreme weather events?

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Ongoing Studies

  • Comprehensive Sea Level Rise and

Recurrent Flooding Study

  • Assessing existing and future flood

vulnerabilities and identifying strategies to ensure our city is resilient to future flooding events

  • Master Drainage Study
  • Detailed inventory and performance

assessment of the City’s stormwater system

  • Stormwater Master Plan
  • Identification and prioritization of needed

improvements to stormwater system

Project Website: http://www.vbgov.com/pwSLR

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  • Higher coastal water levels diminish stormwater system performance
  • Coastal

Flooding

  • Stormwater

Conveyance

  • Combined

Flooding

Combined Impact on Stormwater Analysis

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Comprehensive Sea Level Rise and Recurrent Flood Study

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Study Goal and Outcomes

Goal:

Produce information and strategies that will enable Virginia Beach to establish long-term resilience to sea level rise and associated recurrent flooding Outcomes:

  • Establish a full understanding of flood risk and anticipated changes over planning and

infrastructure time horizons

  • Develop risk-informed strategies, including engineered protection and policy to reduce

short and long-term impacts

  • Produce City-wide and watershed “action plans” for strategy implementation
  • Engage a fine-tuned public outreach process to advance resilience initiatives

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Top 10%

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Observed Acceleration

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Boon et al. 2018 https://www.vims.edu/research/products/slrc/index.php

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VB SLR Planning Scenarios

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Sourced from: Consistent with:

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Timeline of Activities

2015 2016 2017 2018 2019

Planning

  • Scenarios
  • Conceptual

model

Study Progression

  • Grant award
  • Hazard and risk

assessment

  • Essential analysis

to inform design

  • Stormwater

coordination

  • Policy menu

Strategy Focus

  • Structural Alternatives
  • City-wide concepts
  • Performance
  • Down-selection
  • Policy refinement

and rankings

Synthesis

  • Neighborhood and

site alternatives

  • Full Draft

Adaptation Strategy

  • Stakeholder
  • utreach and input

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Hazard and Risk Assessment

Hazard and Risk-driven Decision-Making

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Focus Areas for Adaptation

88% of City’s Risk

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Consequences of Future Without Action

$26 $77 $329

$0 $50 $100 $150 $200 $250 $300 $350 Baseline Scenario 1.5 ft SLR Scenario 3 ft SLR Scenario

Annualized Losses (Millions) 3x increase 12x increase

Compared to Today:

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Informing Design

  • Rainfall/surge correlation
  • >50% of rainfall events occur during

elevated water levels

  • Joint-probability of rainfall/storm surge
  • Concurrent rainfall/surge design values
  • Regional Precipitation Trends
  • Atlas 14 outdated
  • Heavy rainfall increasing, 20% needed over

design life cycle

  • Probable maximum event precipitation
  • Design “check storm”
  • Wind Tides
  • Water level response to wind tide conditions
  • Minimum design tailwaters

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Stormwater Design Standards

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Public Works Design Standards Manual, 2019

  • Major Design Standard Changes to Address Recurrent Flooding and Sea

Level Rise:

  • Requirement to use EPA SWMM software modelling tool for designs with Drainage Area > 20 Ac.
  • Updated Revised Rainfall Depths Based on Future Precipitation Analysis (20% more)
  • Starting Boundary Conditions
  • Specific Requirements Relative to Hydraulic Grade Line
  • Requirement to use City Models Developed of all (31) Drainage Basins
  • Requirement to address Sea Level Rise
  • Requirement to address Groundwater Base Flow in Wet Ponds
  • Draft Manual Complete as of May 1st
  • Public Comment Period: May 1st through August 30th
  • Engineering/Development Community Public Meeting Held August 21st

Draft Document can be found at: https://www.vbgov.com/government/departments/public-works/standards-specs/Pages/default.aspx

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Adaptation Strategies

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Policy Design Protection

Integrated Solution

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Adaptation Strategies

  • Policy Response Document
  • City-wide Flood Protection Strategies
  • Individual Site-Level Strategies
  • Natural and Nature-based Solutions

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Policy Document

  • What it represents:
  • Guidelines for instilling best practices to reduce

long-term flood risk

  • Starting place for evaluation and

implementation by City

  • Unique reflection of City staff perspective and

priorities

  • Not a prescriptive document to be

followed “to the letter”

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Stormwater Design Standard Outputs

Existing Condition 3.1 3.6 4.0 4.4 5.2 5.8 6.2 6.7 8.5 1.5 ft SLR 4.6 5.1 5.5 5.9 6.7 7.3 7.7 8.2 10.0 3.0 ft SLR 6.3 6.9 7.3 7.7 8.5 9.2 9.6 10.1 12.0 Existing Condition 3.2 3.9 4.3 4.8 5.5 6.3 6.9 7.4 9.3 1.5 ft SLR 4.7 5.4 5.8 6.3 7.0 7.8 8.4 8.9 10.8 3.0 ft SLR 6.4 7.2 7.6 8.1 8.8 9.7 10.3 10.8 12.8 Existing Condition 3.2 3.8 4.1 4.5 5.2 5.9 6.5 7.1 8.5 1.5 ft SLR 4.7 5.3 5.6 6.0 6.7 7.4 8.0 8.6 10.0 3.0 ft SLR 6.4 7.1 7.4 7.8 8.5 9.3 9.9 10.5 12.0 Existing Condition 3.6 4.1 4.5 4.9 5.4 6.3 6.8 7.3 8.7 1.5 ft SLR 5.1 5.6 6.0 6.4 6.9 7.8 8.3 8.8 10.2 3.0 ft SLR 7.2 7.7 8.2 8.6 9.2 10.1 10.7 11.2 12.8 Existing Condition
  • 1.8
2.4 3.4 4.2 4.9 6.4 1.5 ft SLR
  • 3.3
3.9 4.9 5.7 6.4 7.9 3.0 ft SLR
  • 6.7
7.6 9.0 10.1 11.1 13.2 Existing Condition
  • 1.5
1.9 2.4 2.8 3.3 4.2 1.5 ft SLR
  • 3.0
3.4 3.9 4.3 4.8 5.7 3.0 ft SLR
  • 6.3
6.9 7.6 8.1 8.8 10.1 Existing Condition
  • 1.3
1.6 2.8 3.4 3.9 4.9 1.5 ft SLR
  • 2.8
3.1 4.3 4.9 5.4 6.4 3.0 ft SLR
  • 4.6
5.0 6.3 6.9 7.5 8.5 Existing Condition 2.8 3.6 4.1 4.7 5.8 6.5 7.1 7.9 10.3 1.5 ft SLR 4.3 5.1 5.6 6.2 7.3 8.0 8.6 9.4 11.8 3.0 ft SLR 5.9 6.7 7.2 7.8 8.9 9.6 10.2 11.0 13.4 Table J-12 Design Tidal Elevations for Virginia Beach All Elevations in feet relative to the North American Vertical Datum (NAVD) of 1988 Location Design Level 1-YR 2-YR 3-YR 5-YR 10-YR 25-YR 50-YR
  • 1. All elevations sourced from direct sampling and statistical analysis of the distribution of water elevations in each watershed
100-YR 500-YR Lynnhaven Bay & River, Eastern Branch Lynnhaven Bay & River, Incl. all areas
  • ther than Eastern
Chesapeake Bay Atlantic Ocean & Rudee Inlet Back Bay, North of Beggars Bridge Creek Back Bay, South of Beggars Bridge Creek North Landing River Elizabeth River Notes:
  • 2. Lynnhaven, Elizabeth River, and Atlantic Ocean elevations were sourced from the 2015 FEMA Flood Insurance Study
  • 3. Back Bay and North Landing River elevations were sourced from CIP 7-030, PWCN-15-0014, WO2A
  • 4. The values do not represent potential wind-driven water levels in the Back Bay and North Landing River
  • 5. The 5-year return period should be used as a minimum elevation for design in Back Bay and North Landing River due to wind tides.
  • 6. Conditions related to a 3-ft rise in sea level include non-linear increases derived from numerical modeling completed by the U.S. Army
Corps of Engineers and the North Carolina Floodplain Mapping Program

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Flood Reduction Strategies

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Natural and Nature-based

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City-wide Structural Flood Protection Strategies

  • Objective:
  • Close coastal flood pathways into

city for maximum flood reduction benefit

  • Product
  • Conceptual solutions
  • Informs direction of detailed efforts
  • Metrics Assessed:
  • Cost
  • Cost-benefits
  • Flood reduction benefits

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Location Renders – Lynnhaven

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Location Renders – Lynnhaven

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Location Renders – Oceanfront

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Location Renders – Oceanfront

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Location Renders – Rudee Inlet

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Location Renders – Rudee Inlet

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Annualized Losses With/Without Implementation

  • Losses updated for BCR
  • Allowable inclusion of social

impacts/benefits

  • Mental stress/anxiety
  • Loss of productivity

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Flood Reduction Strategies

Natural and Nature-based

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Individual Site-Level Strategies

  • Objective:
  • Identify where beneficial,

how to compliment structural strategies,

  • pportunities to introduce green/open

space

  • Product:
  • Map and summary of where cost

beneficial

  • Metrics Assessed:
  • Cost and benefits
  • Parcel, aggregate parcel, watershed,

city-wide levels

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Natural and Nature-based Strategies

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Natural and Nature-Based Strategies

  • What natural and nature-based features (NNBF) could be implemented in

Virginia Beach, in combination with other measures, to reduce flood risk?

Integrated approach that employs the full array of flood risk mitigation strategies by combining NNBF with more conventional flood defense systems and nonstructural policy measures.

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Natural and Nature Based – Suite of Strategies

Non-structural methods focus on creating or enhancing the dominant natural features already present and contributing to flood risk reduction

Beach Nourishment Marsh Restoration, Creation, or Enhancement Forest Restoration, Creation, or Enhancement Submerged Aquatic Vegetation Restoration Oyster Reef Restoration

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Nature Based – Suite of Strategies

Nature-based (or hybrid) techniques integrate soft or 'green' natural and nature-based measures with harder materials for added structure and stability.

Living Shorelines Living Breakwaters Ecologically-Enhanced Revetments

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Natural and Nature-based Strategy Evaluation

  • 1. Identify potentially suitable NNBFs
  • 2. Assess suitability of NNBFs within

the City’s 4 major watersheds

  • 3. Evaluate application of strategies

based on case studies (local and regional)

  • 4. Estimate flood risk reduction

potential of NNBF strategies

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NFWF National Coastal Resilience Fund

  • NFWF is a non-profit organization

dedicated to:

  • “Sustaining, restoring, and enhancing the

nation’s fish, wildlife, plants and habitats for current and future generations”.

  • The NFWF National Coastal Resilience

Fund makes investments to:

  • “Restore and strengthen natural systems so

they can protect coastal communities from the impacts of storms, floods, and other natural hazards and enable them to recover more quickly, while also enhancing habitats for important fish and wildlife populations”.

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Project Team

  • City of Virginia Beach
  • Dewberry
  • Virginia Department of

Game and Inland Fisheries

  • U.S. Fish and Wildlife

Service Back Bay National Wildlife Refuge

  • Old Dominion

University

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Proposed Project Site and Conceptual Design

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Public Engagement

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Spring 2019 Public Engagement

  • Meeting Dates and Locations
  • May 29, 2019 – Virginia Aquarium
  • May 30, 2019 – Kempsville High School
  • July 29, 2019 – Creeds Elementary School
  • July 30, 2019 – Thalia Elementary School
  • July 31, 2019 – Kellam High School
  • August 3, 2019 – Cox High School
  • City to promote by:
  • Social Media – Facebook, Twitter, Instagram, Posts on

Nextdoor Communities and City web sites, News Media Alerts and E-mail “blasts”

  • Flyers were posted at City Libraries and Recreation

Centers

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Next Steps

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Begin Feasibility Analysis Submit Adaptation Strategy Report to NOAA Incorporate Public Input City Review & Stakeholder Engagement Draft Adaptation Strategy Report Re-evaluate and Finalize Alternatives Neighborhood Protection Public Engagement March 2020 November/December 2019 January/February 2020 July/August 2019

Natural and Nature-based

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Discussion

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