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06-16-25 Commission Workshop Agenda City of Atlantic Beach Agenda Commission Workshop Monday, June 16, 2025 - 6:00 p.m. City Hall, Commission Chamber 800 Seminole Road, Atlantic Beach, FL 32233 Invocation and Pledge of Allegiance Page(s) 1. CALL TO ORDER 2. UPDATES TO THE VULNERABILITY ASSESSMENT AND ADAPTATION PLAN COAB Coastal Vulnerability Assessment - Draft COAB Adaptation Plan - Draft 3 - 102 3. PUBLIC COMMENT 4. ADJOURNMENT This meeting will be live-streamed and videotaped. The video recording will be posted within four business days on the City's website. To access live or recorded videos, visit www.coab.us/live. Any person wishing to speak to the City Commission on any matter at this meeting should submit a request to the City Clerk. For your convenience, forms for this purpose are available at the entrance to the Commission Chamber. In accordance with the Americans with Disabilities Act and Section 286.26, Florida Statutes, persons with disabilities needing special accommodation to participate in this meeting should contact the City Clerk’s Office at (904) 247-5821 or at City Hall, 800 Seminole Road, Atlantic Beach, FL 32233, no later than 5:00 PM on the Thursday prior to the meeting. Page 1 of 102 Page 2 of 102 Coastal Vulnerability Assessment Update Planning & Community Development Department 800 Seminole Road Atlantic Beach, FL 32233 June 2025 Agenda Item # 16 Jun 2025 Page 3 of 102 Coastal Vulnerability Assessment City of Atlantic Beach ii Table of Contents Executive Summary 1 Introduction 1-1 1.1 Overview 1-1 1.2 Coastal Resiliency Planning in Florida 1-2 1.3 About this Project 1-3 1.4 Scope of the Vulnerability Assessment 1-4 Methodology 2-1 2.1 General Methodology 2-1 2.2 Sea Level Rise Projections 2-2 2.3 Nuisance Flooding 2-6 2.4 Future Flood Risk 2-7 2.4.1 Storm Surge Modeling 2-7 2.4.2 Stormwater Inundation Modeling 2-10 2.4.3 Combined Inundation 2-12 Exposure Analysis 3-1 3.1 Projected Extents of Nuisance Flooding 3-1 3.2 Projected 100-Year Event Storm Surge 3-1 3.3 Projected Rainfall Induced Flooding 3-1 Sensitivity Analysis 4-22 4.1 Properties and Buildings 4-22 4.2 Critical Facilities 4-23 4.2.1 Critical Facilities Inventory 4-23 4.2.2 Critical Facilities Sensitivity Analysis 4-26 4.2.3 Summary of Critical Facilities Vulnerability 4-27 Next Steps 5-1 5.1 Adaptation Planning 5-1 References 6-1 Agenda Item # 16 Jun 2025 Page 4 of 102 Coastal Vulnerability Assessment City of Atlantic Beach iii Appendices Appendix A – Coastal Flooding Assessment – Applied Technology & Management, Inc. (2019) Appendix B – Vulnerability Assessment Tech Memo – Jones Edmunds & Associates (2019) Appendix C – Future 100-Yr Flood Risk Maps Appendix D – Sensitivity Analysis Tables and Figures Appendix E – Critical Asset Sensitivity Analysis for Tidal Flooding Appendix F – Critical Asset Sensitivity Analysis for Rainfall-Induced Flooding Appendix G – Critical Asset Sensitivity Analysis for Surge Flooding List of Tables Table 2-1 Matrix of Evaluated Flood Scenarios ....................................................................... 2-2 Table 2-2 Projected Future Mean Sea Levels - Mayport Bar Pilot's Dock (NAVD88) ............... 2-3 Table 2-3 Summary of Surge Elevation Ranges...................................................................... 2-8 Table 2-4 Existing Conditions Rainfall Depths ....................................................................... 2-11 Table 2-5 Rainfall Change Factors and Future Conditions Rainfall Depths ........................... 2-11 Table 4-1 Vulnerability of Property ........................................................................................ 4-22 Table 4-2 Critical and Regional Significant Assets by Type ................................................... 4-25 Table 4-3 Percentage of Assets Flooded by Asset Type for Tidal Flooding Scenarios ............ 4-1 Table 4-4 Percentage of Assets Flooded by Asset Type for Rainfall Flooding Scenarios ........ 4-2 Table 4-5 Percentage of Assets Flooded by Asset Type for Surge Flooding Scenarios .......... 4-3 List of Figures Figure 1-1 – Atlantic Beach Zoning Map (Updated in 2023) .................................................... 1-1 Figure 1-2 – Global Average Sea Level Change (US Global Change Research Program) ...... 1-3 Figure 1-3 – Relative Sea Level Rise – Mayport Bar Pilot’s Dock (NOAA) .............................. 1-4 Figure 2-1 – Comparison of Projected Sea Level Rise Data Sets at Mayport .......................... 2-3 Figure 2-2 - Hurricane Matthew Water Levels - October 2016 at Mayport Bar Pilot’s Dock ..... 2-4 Figure 2-3 – Hurricane Irma Water Levels - September 2017 at Mayport Bar Pilot’s Dock ...... 2-4 Figure 2-4 – Tropical Storm Nicole Water Levels – November 2022 at Mayport Bar Pilot’s Dock ............................................................................................................................................... 2-5 Figure 2-5 Annual Exceedance Probability Curve - Mayport Bar Pilot's Dock (NOAA) ............ 2-7 Figure 2-6 – Illustration of a Coastal Wave Transect ............................................................... 2-9 Figure 2-7 – Illustration of Coastal Effects of Sea Level Rise .................................................. 2-9 Figure 2-8 – Future Conditions Impervious Update Area (2018 Stormwater Master Plan Update) ............................................................................................................................................. 2-10 Agenda Item # 16 Jun 2025 Page 5 of 102 Coastal Vulnerability Assessment City of Atlantic Beach iv Figure 3-1 – High-Tide Nuisance Flooding Depth Under Existing Conditions (2025) ............... 3-2 Figure 3-2 High-Tide Nuisance Flooding Under 2050 Intermediate-Low SLR Conditions (2025)3- 3 Figure 3-3 – High-Tide Nuisance Flooding Under 2050 Intermediate SLR Conditions (2025) . 3-4 Figure 3-4 – High-Tide Nuisance Flooding Under 2080 Intermediate-Low SLR Conditions (2025) ............................................................................................................................................... 3-5 Figure 3-5 – High-Tide Nuisance Flooding Under 2080 Intermediate SLR Conditions (2025) . 3-6 Figure 3-6 – 100-Year Storm Surge Flooding Depth Under Existing Conditions (2025) ........... 3-7 Figure 3-7 – 100-Year Storm-Surge Flooding Under 2050 Intermediate-Low SLR Conditions (2025) ..................................................................................................................................... 3-8 Figure 3-8 – 100-Year Storm-Surge Flooding Under 2050 Intermediate SLR Conditions (2025) 3- 9 Figure 3-9 – 100-Year Storm-Surge Flooding Under 2080 Intermediate-Low SLR Conditions (2025) ................................................................................................................................... 3-10 Figure 3-10 – 100-Year Storm-Surge Flooding Under 2080 Intermediate SLR Conditions (2025) ............................................................................................................................................. 3-11 Figure 3-11 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under Existing Conditions (2025) .................................................................................................................. 3-12 Figure 3-12 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under Existing Conditions (2025) .................................................................................................................. 3-13 Figure 3-13 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under 2050 Intermediate-Low SLR Conditions (2025) .............................................................................. 3-14 Figure 3-14 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under 2050 Intermediate SLR Conditions (2025) ..................................................................................... 3-15 Figure 3-15 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under 2050 Intermediate-Low SLR Conditions (2025) .............................................................................. 3-16 Figure 3-16 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under 2050 Intermediate SLR Conditions (2025) ..................................................................................... 3-17 Figure 3-17 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under 2080 Intermediate-Low SLR Conditions (2025) .............................................................................. 3-18 Figure 3-18 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under 2080 Intermediate SLR Conditions (2025) ..................................................................................... 3-19 Figure 3-19 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under 2080 Intermediate-Low SLR Conditions (2025) .............................................................................. 3-20 Figure 3-20 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under 2080 Intermediate SLR Conditions (2025) ..................................................................................... 3-21 Figure 4-1 - Critical Asset Locations ...................................................................................... 4-24 Agenda Item # 16 Jun 2025 Page 6 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 1 Executive Summary In 2019, the City of Atlantic Beach completed its initial Vulnerability Assessment. Since then, state regulations have been introduced to standardize these assessments, State Statute 380.093 has clarified reporting requirements, and our modeling capabilities have significantly improved. As a result, an update to the plan is now necessary. Sea levels have risen measurably over the years in Atlantic Beach. The question is how will this rate of sea level rise change in the future and how will it affect us as a City? To help answer these questions, the City embarked on a study to evaluate the vulnerability of the City with respect to nuisance flooding and storm induced flooding from sea level rise in the 25- and 55-year timeframe. This update includes new modeling for the timeframes. This report details the methodology utilized to develop a statistically based approach to vulnerability from sea level rise and assessed the vulnerability of critical facilities and infrastructure. The assessment also included an evaluation of the potential impact to all properties and structures within the city limits. The results of this effort are series of maps that are essentially future versions of the FEMA Flood Insurance Rate Maps utilized for planning and building requirements today. The analysis reveals that there may be significant future impacts from sea level rise in the not so distant future that will have to be taken into account with respect to planning, development and redevelopment. This report forms the basis for the next step in planning for the impacts of sea level rise through development of an adaptation plan. The adaptation plan will consider policies, planning measures, future projects, etc. to help adapt to and mitigate for impacts to vulnerable areas of the City. This project was made possible by a Resilient Florida Grant Program (RFGP) provided by the Florida Department of Environmental Protection’s (FDEP) Resilient Coastlines program and a Community Development Block Grant Mitigation Program provided by the Department of Commerce. The following City of Atlantic Beach staff provided content: Steve Swann; P.E., City Engineer Amanda Askew; AICP, Neighborhoods Department Director Abrielle Genest, Principal Planner and Environmental Coordinator Agenda Item # 16 Jun 2025 Page 7 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 1-1 Introduction 1.1 Overview The City of Atlantic Beach is one of three small coastal communities in northeast Florida that make up the “Beaches” of Jacksonville. The City consists of three square miles with a population of approximately 14,000, is located between two miles of Atlantic Ocean beachfront on the east and the expansive marsh and estuarine environment of the San Pablo Creek / Atlantic Intracoastal Waterway (AICW) on the west. Atlantic Beach is a near fully-developed municipality where the predominant land use is residential consisting of stable and well-established neighborhoods. Figure 1-1 – Atlantic Beach Zoning Map (Updated in 2023) Agenda Item # 16 Jun 2025 Page 8 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 1-2 Atlantic Beach contains two commercial corridors: the north side of Atlantic Boulevard (SR10) extending from the ocean westerly to the AICW, and Mayport Road (SR A1A), extending from Atlantic Boulevard northerly to the municipal limits of the City at Dutton Island Road. The City possesses a unique character and “personality” where a high quality of life, diverse recreational activities, preservation of community character and protection of natural resources are priorities to both residents and elected officials. Since the City is near full build out, current development consists of redevelopment and scattered infill. In 2019, City staff began observing the development of lots that were historically untouched primarily due to low lying topography and proximity to the 100-year floodplain. This trend has continued and is likely due to a lack of undeveloped land and the continued attractiveness of the area. 1.2 Coastal Resiliency Planning in Florida Scientists from around the world have been studying climate change and the resulting sea level rise impacts for decades. Today, multiple sources of data are available to predict realistic scenarios of future sea levels and their impacts on coastal communities. Some cities, such as Miami, are already seeing impacts from sea level changes prompting immediate adaptation measures. The state of Florida began their first organized adaptation planning efforts in 2009 which led to the Community Planning Act (CPA) in 2011. The CPA gave local governments the option to create adaptation plans. However, the state did not require municipalities to address sea level rise until 2015 when the “Peril of Flood” statute was passed which forced municipalities to address sea level rise in their comprehensive plans. Atlantic Beach incorporated “Peril of Flood” amendments in to its comprehensive plan in 2019. In 2018, recognizing the need for coastal communities to assess potential impacts from sea level rise, the Florida Department of Environmental Protection’s Resilient Coastlines Program awarded its 16 resiliency planning grants to coastal communities including Atlantic Beach, resulting in the 2019 Coastal Vulnerability Assessment. The purpose of Atlantic Beach’s grant was to provide funding for planning purposes to help prepare our community for current and future effects of rising sea levels, initially through the preparation of this Vulnerability Assessment. To incorporate all of COAB’s public utility assets, the VA was revised in 2021 to add the area located between Wonderwood Drive and AB city limits. In the 2022 Florida Statute Section 380.093 update, specific data collection standards for all Vulnerability Assessments were established. Some of these standards include identifying critical community infrastructure and assets that are vulnerable to flooding under existing and projected future conditions and utilizing the NOAA 2022 intermediate low and intermediate sea-level rise projections for the 2050 and 2080 planning horizons. COAB has completed this update to satisfy the statute, to leverage additional grant funding, and as part of its continuing efforts to become a more resilient community. Agenda Item # 16 Jun 2025 Page 9 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 1-3 1.3 About this Project On average globally, the sea level has risen by about 8 inches since scientific record keeping began in 1880. This rate has increased in recent decades to a little more than an inch per decade. Global average sea level has risen by about 7–8 inches (about 16–21 cm) since 1900, with about 3 of those inches occurring since 1993. In addition to the global average sea level rise, local sea level rise – sometimes called “relative sea level rise” – happens at different rates in different places. Local sea level rise is affected by the global sea level rise, but also by local land motions, and the effects of tides, currents, and winds. Figure 1-2 shows an increase in global average sea level since 1880, in inches. Note that the blue line, tide gauge data, becomes steeper in more recent decades. This indicates an increasing rate of change. The surrounding light blue-shaded area shows upper and lower 95% confidence intervals and the orange line shows sea level as measured by satellites for comparison (1993- 2016). (U.S. Global Change Research Program, 2017) As sea levels have risen, the incidence of nuisance flooding or “sunny day” flooding during spring tide events at certain times of the year have increased five to ten fold since the 1960s in several U.S. coastal cities and rates of increase are accelerating in over 25 Atlantic and Gulf Coast cities. In Atlantic Beach, nuisance flooding resulting in overtopped roads is occurring now in areas of Atlantic Beach such as Dutton Island Road and West Plaza. Figure 1-2 – Global Average Sea Level Change (US Global Change Research Program) Agenda Item # 16 Jun 2025 Page 10 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 1-4 The closest National Oceanic and Atmospheric Association (NOAA) primary tidal gauge to Atlantic Beach is located at the Mayport Bar Pilot’s Dock (NOAA tide gauge No. 8720218) near the ferry slip. Figure 1-3 depicts the relative change in sea level at the Mayport Bar Pilot’s Dock over the 90-year history of this station. The current local rate of sea level change is approximately one-inch every decade. (https://tidesandcurrents.noaa.gov/sltrends/) Figure 1-3 – Relative Sea Level Rise – Mayport Bar Pilot’s Dock (NOAA) Although there is uncertainty relating to the change in rate of sea level rise, there is no uncertainty that sea level is rising in our area. As sea levels rise, incidents of nuisance flooding will increase and flooding due to severe weather events will affect larger areas of the City. To aid in both planning and assessing the City’s potential vulnerability under future scenarios with higher sea levels, the City conducted a rigorous technical analysis to determine just what those effects may be and how they will impact residents and critical infrastructure. 1.4 Scope of the Vulnerability Assessment The vulnerability assessment is focused on providing a quantitative analysis of property, infrastructure and habitats within the City’s municipal boundaries under future predicted sea level scenarios using widely accepted scientific analyses. To complete the vulnerability assessment update and analyses required to make these predictions, the City selected Jones Edmunds & Associates, a consulting firm with many years of local experience as well as experience conducting similar analyses throughout the coastal areas of the Southeast United States. Their task was to compile the topographical data, critical and regionally significant asset data, and flood scenario-related data to perform the Vulnerability Assessment as defined in Section 380.093, Florida Statutes. According to Florida Statutes and FDEP guidance, the following are requirements for this task: Agenda Item # 16 Jun 2025 Page 11 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 1-5 • Include all critical assets (e.g. sewage lift stations, schools, evacuation routes, etc.) owned or maintained by the City of Atlantic Beach (COAB). • Utilize the most recent publicly available digital elevation model (DEM). • Ensure Geographic Information System (GIS) data adheres to FDEP’s GIS Data Standards and data sources are defined in the associated metadata. • Include the 2022 National Oceanic and Atmospheric administration’s (NOAA) intermediate-low and intermediate sea-level rise projections for 2050 and 2080. • Storm-surge data must be equal to or exceed the 100-year return-period for a flood event. • Identify data gaps where missing or low-quality information may limit the VA’s extent of reduce the accuracy of the results and rectify any gaps as necessary. The technical analyses that form the basis of the vulnerability assessment began with the current Federal Emergency Management Association (FEMA) Flood Insurance Rate Maps (FIRMs) as the baseline condition and utilized NOAA 2022 Intermediate-Low and Intermediate Sea Level Rise (SLR) scenarios for predicted 2050 and 2080 conditions as follows: • Mean Higher High Water (MHHW) modeling to predict frequency of nuisance flooding • Storm surge modeling to predict coastal flooding • Stormwater modeling to predict upland rain induced flooding • Composite coastal flooding and upland rain induced flood mapping to delineate future flood hazard areas • Assessment of property, infrastructure and habitat impacted within flood zones of composite future flood mapping MHHW is the higher of the two daily tides averaged over a 19-year tidal epoch. The methodology is summarized in Section 2 and the results of these analyses are presented in Sections 3 & 4 of this report. A more detailed description of the methodology is attached in Appendices A & B. Agenda Item # 16 Jun 2025 Page 12 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-1 Methodology 2.1 General Methodology For this vulnerability assessment, the baseline is the existing mean higher high water (MHHW) level and the current FEMA FIRMs for the City. The MHHW level, which is the average of the higher of each of the two daily high tides, provides an indication of the frequency of sunny day flooding occurrences due to normal tidal cycles and does not include storm events. The FIRMs for the City of Atlantic Beach provide a prediction of what the 100-year flood event water levels will be. While FEMA does not consider sea level rise (SLR) in the development of a FIRM, they do conduct a rigorous analysis of storm surge flooding and flooding due to upland inundation from rainfall. FIRMs are currently used to map properties with respect to the 100-year flood event to set flood insurance premiums as well as to determine where stricter building and development standards apply for flood protection. Given the common use of FIRMs for regulatory purposes and general familiarity many people have with these maps, this vulnerability assessment utilizes the FEMA methodology to predict the extents of a 100-year flood event in the future considering the effects of SLR. The technical analyses that serve as the foundation for this vulnerability assessment resulted in essentially producing maps of what the FIRM may look like in 25 and 55 years considering sea level rise. The analysis also incorporated the loss of soil storage that may result from rising sea levels as well as predicted future build-out conditions within the city boundaries. Surge analyses were conducted for both the Atlantic Ocean side of the City and the Intracoastal Waterway side of the City utilizing the same methodology FEMA used to develop the FIRMs for this area. It is important to note that as water depth increase with SLR, there is a corresponding increase wave heights and wave runup. Hence, the surge analyses being specifically analyzed with future water level conditions and not just added to the predicted increased sea level height. Upland rainfall induced flooding was analyzed using the Interconnected Pond Routing (ICPR) model developed for the City’s 2018 Stormwater Master Plan Update for every drainage basin within the City. This was a necessary step given the flat topography of the City and impacts of tide height on the performance of the drainage systems. Both analyses utilized current conditions as a reference check and used the intermediate-low and intermediate NOAA 2022 SLR projections. Florida Statue 380.093(3)(d)(3)(c) establishes planning horizons based on the year of assessment. COAB received FDEP approval to utilize 2050 and 2080 planning horizons for inundation analyses to develop future 100-yr and 500-yr storm event predictions. Table 2-1 summarizes the flood scenarios that were included in this assessment. Scenarios highlighted in orange demote the scenarios required by Florida Statutes. Flood stages were determined for each of these scenarios, and inundation extents/depths were mapped against the 2018 DEM. Agenda Item # 16 Jun 2025 Page 13 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-2 Table 2-1 Matrix of Evaluated Flood Scenarios Flooding Type Tidal Flood Days MHHW +2 feet 100-Year 500-Year Tidal/Sunny-Day Flooding Existing X X 2050 Intermediate-Low X X 2050 Intermediate X X 2080 Intermediate-Low X X 2080 Intermediate X X Rainfall-Induced Flooding Existing X X 2050 Intermediate-Low X X 2050 Intermediate X X 2080 Intermediate-Low X X 2080 Intermediate X X Storm-Surge Flooding Existing X 2050 Intermediate-Low X 2050 Intermediate X 2080 Intermediate-Low X 2080 Intermediate X 2.2 Sea Level Rise Projections COAB lies approximately 3 miles south of the Mayport NOAA SLR gauge. The next closest tide station is in Fernandina Beach. The mean sea level at the Mayport gauge exceeds the mean sea level at the Fernandina Beach gauge. Therefore, in accordance with Section 380.093(3)(d)(3)(d), F.S., this VA applies to the Mayport gauge only to the coastal and Intracoastal Waterway (ICWW) portions of COAB. Section 380.093(3)(d)(2), F.S., requires Vulnerability Assessments “make use of the best available information through the Florida Flood Hub”. The projections that were released by the Flood Hub at the time of this study did not include the 2080 planning horizon. Based on this, Jones Edmunds used the US Army Corps of Engineers (USACE) Sea Level Analysis Tool (SLAT) to obtain the NOAA 2022 SLR projections for the Mayport Tide Station, which are slightly higher (approximately 0.1 foot) than the statewide projections. The NOAA 2022 SLR projections from the Mayport Tide station were used instead of the statewide calculations because they are slightly higher than the statewide values and the gauge is near COAB. SLR projections for the intermediate-low and intermediate SLR elevations for 2050 and 2080 were calculated using the Agenda Item # 16 Jun 2025 Page 14 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-3 NOAA 2022 SLR projection curves for the Mayport Tide Station. SLR estimates at this gauge are presented graphically in Figure 2-1 and in tabular form in Table 2-2. Figure 2-1 – Comparison of Projected Sea Level Rise Data Sets at Mayport Table 2-2 Projected Future Mean Sea Levels - Mayport Bar Pilot's Dock (NAVD88) Planning Horizon Projected SLR (feet) MSL Elevation (feet-NAVD88) Intermediate- Low Intermediate Existing Intermediate- Low Intermediate Existing Conditions N/A N/A 2.5 N/A N/A 2050 0.61 0.74 N/A 3.11 3.24 2080 1.27 1.96 N/A 3.77 4.46 For comparison, water elevations recorded during Hurricane Matthew in October 2016, Hurricane Irma in September 2017, and Tropical Storm Nicole in November 2022 are presented below. The highest water level recorded during Hurricane Matthew was 5.23 feet NAVD88, 5.58 feet NAVD88 during Hurricane Irma and 5.54 feet NAVD88 during Tropical Storm Nicole. 0 2 4 6 8 10 12 14 2044 2054 2064 2074 2084 2094 2104 2114Projected Sea Level (ft, NAVD88)NOAA 2017 - Int-High NOAA 2017 - High NOAA 2017 - Extreme CARSWG 2016 - High CARSWG 2016 - Highest USACE 2013 - High USACE 2013 - Int IPCC AR5 RCP 8.5 - Median Agenda Item # 16 Jun 2025 Page 15 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-4 Figure 2-2 - Hurricane Matthew Water Levels - October 2016 at Mayport Bar Pilot’s Dock Figure 2-3 – Hurricane Irma Water Levels - September 2017 at Mayport Bar Pilot’s Dock Agenda Item # 16 Jun 2025 Page 16 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-5 Figure 2-4 – Tropical Storm Nicole Water Levels – November 2022 at Mayport Bar Pilot’s Dock Agenda Item # 16 Jun 2025 Page 17 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-6 2.3 Nuisance Flooding Nuisance flooding, sometimes referred to as "sunny day" flooding, is flooding that leads to public inconveniences such as road closures. The City currently experiences a limited degree of nuisance flooding in several locations. As sea levels continue to rise, nuisance flooding will become more prevalent and extensive. For this effort, nuisance flooding is considered to be occurring when the tide level is approximately one foot greater than the Mean Higher High Water (MHHW) level at Mayport. This occurs at least once every year as can be seen in the statistical summary presented in Figure 2-6. This chart indicates that there is 99% probability of water levels exceeding MHHW by at least 1’ (0.3 m) on an annual basis. Similarly, there is a 50% probability of tidal levels exceeding MHHW by 1.5’ (0.45 m) in any given year and a 10% probability of tidal levels exceeding MMHW by 2’ (0.6 m) in any given year. The current MHHW level in our area is at elevation 2’, and based on observations, nuisance flooding can start to occur when water levels exceed 3’. Areas of the City that are at or below 3’ elevation include the Dutton Island access road and portions of West Plaza, both areas that currently experience nuisance flooding. Given that there is a 99% probability of water levels of at least 1’ above MHHW occurring on annual basis as shown on Figure 2-6, nuisance flooding in portions of Atlantic Beach is expected to occur at least once every year at a minimum. Flooding during king tide at West Plaza - 2020 Flooding at Buccaneer Lift Station - 2021 King Tide Flooding at Dutton Island Rd. W - 2020 Agenda Item # 16 Jun 2025 Page 18 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-7 Figure 2-5 Annual Exceedance Probability Curve - Mayport Bar Pilot's Dock (NOAA) To estimate nuisance flooding in the future, NOAA’s Digital Coast tools were utilized to overlay one foot of water level on top of the predicted future sea levels over the planning period. As updated digital elevation models become available, the City will undertake a more rigorous analysis of the future frequency and extent of nuisance flooding and will update the Vulnerability Assessment as necessary. 2.4 Future Flood Risk As sea levels rise there will generally be an increase in flood risk. This increased risk is not reflected in the current FEMA Flood Insurance Rate Maps (FIRMs) for the City. Estimating the extent of future risk requires updating the FIRMs to account for impacts in both storm surge and rainfall induced flooding under higher sea level conditions. The following sections describe the methodology utilized to develop the information required to assess future flood risks for the City. 2.4.1 Storm Surge Modeling Higher sea levels will result in increased storm surge levels and wave heights and will exacerbate nuisance flooding from extreme high tides. The combination of a higher sea level with a storm surge can result in larger storm impacts and coastal vulnerability from a flooding perspective than are currently experienced. Agenda Item # 16 Jun 2025 Page 19 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-8 FIRMs are updated on a regular basis (typically every 10 years) and FEMA only considers the existing mean sea level at the time of the update and does not account for SLR. For the vulnerability assessment, an analysis based on the FEMA flood mapping protocol was conducted to evaluate coastal flooding and wave risks under projected SLR scenarios for 25, 50 and 100 years. The storm surge inundation modeling was conducted by ATM using the effective 2018 FEMA Flood Insurance Study (FIS) for Duval County and site-specific modeling using FEMA’s Coastlal Hazard Analysis and Mapping Program (CHAMP) Version 2.0 model suite, including the FEMA Wave Height Analysis for Flod Insurance Studies (WHAFIS) overland wave propogation model. The site-specific modeling was developed by Geosyntec for COAB’s VA that was updated in 2021. The future conditions modeling that was completed in 2021 used NOAA 2017 intermediate- high SLR projections to project surge flooding fof the 100-year event. For this VA,ATM updated the site-specific model using the NOAA 2022 intermediate-low and intermediate SLR projections for the 2050 and 2080 planning horizons. Also, the storm surge modeling utilized existing FEMA stillwater elevation (SWEL) results (that don’t include waves) for a 100-year event and increased the elevations to account for the projected increase in sea levels in the future. The next step required updating wave transect modeling on top of the increased SWEL elevations to predict 100-year base flood elevations under future higher sea levels. Figure 2-6 depicts a typical FIRM cross-section and the concept of SWEL and wave setup on top of the SWEL. Appendix A contains a detailed description of this approach used in the 2019 Vulnerability Assessment, 2021 revision and this update . Note that wave modeling is very sensitive to water depth and increased future sea levels will allow larger waves to travel further inland during storms because there is more area inundated with higher future SWEL. This is illustrated in Figure 2-7. The result of these analyses were FIRM type flood maps for future higher sea level scenarios. Table 2-3 sumarizes the range of storm-surge flood elevations acroos COAB for each of the storm-surge flooding scenarios. Table 2-3 Summary of Surge Elevation Ranges Flood Scenario Surge Elevation Range (feet NAVD88) 100-Year, Existing Conditions 5.2 to 25.3 100-Year, 2050 Intermediate-Low 5.8 to 25.9 100-Year, 2050 Intermediate 5.9 to 26.0 100-Year, 2080 Intermediate-Low 6.4 to 26.5 100-Year, 2080 Intermediate 7.1 to 27.2 Agenda Item # 16 Jun 2025 Page 20 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-9 Figure 2-6 – Illustration of a Coastal Wave Transect Figure 2-7 – Illustration of Coastal Effects of Sea Level Rise Agenda Item # 16 Jun 2025 Page 21 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-10 2.4.2 Stormwater Inundation Modeling To determine how rainfall-induced flooding may be impacted by sea level rise and new development within the City, the hydrologic and hydraulic parameters in the Interconnected Pond Routing (ICPR) Version 4 models that were developed during the City’s 2018 Stormwater Master Plan update were adjusted to reflect projected increases in impervious area from future development, increased boundary conditions and node initial conditions from rising sea levels, and reduced soil storage from rising sea levels. The rates of future development that were developed for the City’s 2018 Stormwater Master Plan update were used to estimate the impervious area in the City in 2050 and 2080. The estimated future impervious values were applied to the already modeled stormwater drainage basins so that modeled runoff accurately reflects future conditions. The areas updated for future increases in impervious area for the 2050 and 2080 conditions are shown in Figure 2-9. Figure 2-8 – Future Conditions Impervious Update Area (2018 Stormwater Master Plan Update) Agenda Item # 16 Jun 2025 Page 22 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-11 The ground water table is also expected to rise with rising sea levels because of consistently higher tides. This increase in ground water levels will reduce the amount of soil storage available for rainfall to infiltrate and will increase the volume of runoff during storm events. The decrease in soil storage will be more marked in areas directly adjacent to the coastline and will be reduced further inland. To account for these projected changes, the basin criteria in the stormwater model were adjusted to decrease soil storage capacity in conjunction with expected future sea level elevations. To model and map rainfall-induced flooding, Jones Edmunds collected NOAA Atlas 14 rainfall data, future conditions rainfall-change factors, and the COAB existing rainfall- induced flooding model. Peak stage results from the future drainage conditions models were used to map the predicted rainfall-induced flood risk in the City in 2050 and 2080 for a series of 24-hour rain events including the 100- and 500-year return period rainfall events. Table 2-4 summarizes the rainfall depths for each of the storm events. COAB’s model uses the Florida Modified Type II Rainfall Distribution for this VA. Table 2-4 Existing Conditions Rainfall Depths Storm Event Rainfall Depth Range (inches) 100-Year/24-hour 12.6 500-Year/24-hour 17.3 To model future conditions rainfall-induced flooding, Jones Edmunds collected rainfall change factors from the Florida International University (FIU) Sea-Level Solutions Center based on the CORDEX model, which is consistent with the change factors used by the Northeast Florida Regional Planning Council to conduct their regional vulnerability assessment. Table 2-5 shows the change factors that were used from the FIU website and the resulting rainfall depth ranges for the required 2050 and 2080 planning horizons. Table 2-5 Rainfall Change Factors and Future Conditions Rainfall Depths Storm Event 2050 Change Factor 2080 Change Factor 2050 Rainfall Depth Range (inches) 2080 Rainfall Depth Range (inches) 100-Year/24-hour 1.27 1.36 16.0 17.1 500-Year/24-hour 1.29 1.39 22.3 24.1 The rainfall-induced flood model was developed by COAB and Jones Edmunds in 2018 using the modeling software Interconnected Pond Routing Version 4 (ICPR4). The results were then mapped using the 5-foot-by-5-foot digital elevation model (DEM) generated from the 2007 City of Jacksonville Light Detection and Ranging (LiDAR) data. Section 380.093, F.S., required this VA Agenda Item # 16 Jun 2025 Page 23 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 2-12 to be performed using the most recent LiDAR dataset. Jones Edmunds compared the DEMs from the 2007 and 2018 LiDAR datasets to determine if differences between the two would invalidate parts of the model. The differences in the datasets were generally less than 0.5 foot. Areas where differences were greater were confined to new developments that occurred between LiDAR flights. Minimal new developments that were not already accounted for in COAB’s model have occurred, and none of the new developments have a significant impact on the rainfall-induced flood modeling. The models will be updated if necessary when newer data is available. See Appendix B for a detailed description of this modeling approach from the 2019 VA. 2.4.3 Combined Inundation The future storm surge flood risk maps were then combined with the rainfall induced inundation maps for the 100-year return period storm for 2050 and 2080. These maps are attached as Appendix C separately. Where there was overlap between the flood risk mapping, the higher inundation estimate from the two mapping efforts was selected. These maps provide for a spatial estimate of future flood risk that will serve as the basis for the vulnerability assessment. Note that rainfall induced flood risk and coastal surge flood risk are usually evaluated relatively independently because the two forms of flood risk are neither fully dependent nor fully independent. Therefore, traditional statistical approaches are not applicable and the standard procedure to deal with this is to evaluate the two independently using common sea level rise scenarios and then take the higher of the combined identified risk at each location. Agenda Item # 16 Jun 2025 Page 24 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-1 Exposure Analysis 3.1 Projected Extents of Nuisance Flooding Figures 3-1 through Figure 3-5 depicts nuisance, or sunny day, flooding that the City may experience based on anticipated sea level rise. The mapped extent of projected nuisance flooding is based on the annual probability of experiencing tide levels of at least 2 foot greater than the MHHW. Future nuisance flooding is predicted to increase substantially on the western side of the City adjacent to the Intracoastal Waterway and along Sherman Creek and the Aquatic Gardens neighborhood. Nuisance flooding seaward of the mapped extents are expected to be more frequent than an annual event. 3.2 Projected 100-Year Event Storm Surge Figures 3-6 through 3-10 illustrates the projected extent of the storm surge expected from a 100- year storm event in Atlantic Beach in 2050 and 2080. Flood depth rasters were developed for each of the scenarios using the storm-surge flood elevations presented in Section 2.4.1 and the 2018 LiDAR DEM. 3.3 Projected Rainfall Induced Flooding Figures 3-11 through 3-20 illustrates the projected rainfall induced flooding from a 100-year storm in Atlantic Beach for years 2050 and 2080. These maps reflect future conditions with increased impervious surface from development. In addition, stormwater infrastructure performance is compromised and the water table is elevated due to sea level rise projections. This map is combined with the projected previous storm surge maps to create the projected 100 Year Future Flood Zones used in the vulnerability assessment Agenda Item # 16 Jun 2025 Page 25 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-2 Figure 3-1 – High-Tide Nuisance Flooding Depth Under Existing Conditions (2025) Agenda Item # 16 Jun 2025 Page 26 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-3 Figure 3-2 High-Tide Nuisance Flooding Under 2050 Intermediate-Low SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 27 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-4 Figure 3-3 – High-Tide Nuisance Flooding Under 2050 Intermediate SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 28 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-5 Figure 3-4 – High-Tide Nuisance Flooding Under 2080 Intermediate-Low SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 29 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-6 Figure 3-5 – High-Tide Nuisance Flooding Under 2080 Intermediate SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 30 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-7 Figure 3-6 – 100-Year Storm Surge Flooding Depth Under Existing Conditions (2025) Agenda Item # 16 Jun 2025 Page 31 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-8 Figure 3-7 – 100-Year Storm-Surge Flooding Under 2050 Intermediate-Low SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 32 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-9 Figure 3-8 – 100-Year Storm-Surge Flooding Under 2050 Intermediate SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 33 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-10 Figure 3-9 – 100-Year Storm-Surge Flooding Under 2080 Intermediate-Low SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 34 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-11 Figure 3-10 – 100-Year Storm-Surge Flooding Under 2080 Intermediate SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 35 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-12 Figure 3-11 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under Existing Conditions (2025) Agenda Item # 16 Jun 2025 Page 36 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-13 Figure 3-12 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under Existing Conditions (2025) Agenda Item # 16 Jun 2025 Page 37 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-14 Figure 3-13 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under 2050 Intermediate-Low SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 38 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-15 Figure 3-14 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under 2050 Intermediate SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 39 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-16 Figure 3-15 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under 2050 Intermediate-Low SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 40 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-17 Figure 3-16 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under 2050 Intermediate SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 41 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-18 Figure 3-17 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under 2080 Intermediate-Low SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 42 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-19 Figure 3-18 – Rainfall-Induced Flooding for the 100-Year, 24-Hour Storm Event Under 2080 Intermediate SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 43 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-20 Figure 3-19 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under 2080 Intermediate-Low SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 44 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 3-21 Figure 3-20 – Rainfall-Induced Flooding for the 500-Year, 24-Hour Storm Event Under 2080 Intermediate SLR Conditions (2025) Agenda Item # 16 Jun 2025 Page 45 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-22 Sensitivity Analysis 4.1 Properties and Buildings Based on the projected impacts of sea level rise, there will likely be additional properties in the future that will be subject to both nuisance flooding and located within a Special Flood Hazard Area (SFHA, which is the area inundated by flood waters from a 100-year storm event). Table 4- 1 illustrates the total value of land and buildings impacted for nuisance flooding and storm surge maps for 2050 and 2080. For the 100-year flood risk assessment, parcels were only counted if water was projected to reach their center. Counting every parcel touched would have included beach front parcels which are actually at higher elevations and typically have higher assessed values. All values are provided in today’s dollar. Table 4-1 – Vulnerability of Property 2050 Intermediate- Low Scenarios Number of Parcels Impacted (% of All Parcels) Number of Buildings on Impacted Parcels Land Value of Impacted Parcels Building Value of Impacted Parcels Taxable Value of Impacted Parcels Nuisance Flooding 625 (10%) 738 $290,351,970 $269,609,632 $282,169,878 Storm Surge 701 (11%) 803 $234,070,885 $224,527,108 $230,900,463 2050 Intermediate Scenarios Number of Parcels Impacted (% of All Parcels) Number of Buildings on Impacted Parcels Land Value of Impacted Parcels Building Value of Impacted Parcels Taxable Value of Impacted Parcels Nuisance Flooding 779 (12%) 667 $303,272,940 $280,466,531 $293,224,628 Storm Surge 776 (12%) 887 $255,644,673 $241,941,745 $248,670,883 2080 Intermediate- Low Scenarios Number of Parcels Impacted (% of All Parcels) Number of Buildings on Impacted Parcels Land Value of Impacted Parcels Building Value of Impacted Parcels Taxable Value of Impacted Parcels Nuisance Flooding 842 (13%) 947 $360,909,500 $326,838,789 $340,582,741 Storm Surge 1,291 (21%) 1,200 $420,541,921 $356,443,699 $365,651,140 Agenda Item # 16 Jun 2025 Page 46 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-23 2080 Intermediate Scenarios Number of Parcels Impacted (% of All Parcels) Number of Buildings on Impacted Parcels Land Value of Impacted Parcels Building Value of Impacted Parcels Taxable Value of Impacted Parcels Nuisance Flooding 1,276 (20%) 1167 $489,165,039 $424,150,388 $439,807,776 Storm Surge 1,736 (27%) 1,833 $707,341,778 $589,529,782 $605,611,756 Nuisance flooding totals are important because they reflect what is likely to happen at least annually year. By 2080, nuisance flooding is predicted to impact 13% to 20% of properties in Atlantic Beach totaling upwards of $439,807,776 in taxable value. In 2080, 21% to 27% of properties will be impacted by storm surge totaling up to $605,611,756 in taxable value. Existing development standards in place will help mitigate the impacts from sea level rise on property up to a certain point. These standards relate to the required minimum finished floor elevation (FFE) for all new construction that creates a buffer between flood water and living areas. The City currently requires a minimum finished floor elevation of 8.5 feet above mean sea level or 2.5 feet above the 100- year flood elevation or base flood elevation (BFE) per Chapter 24, Sec. 24-90(c)(1) of the Land Development Code. However, the buffer provided by FFE standards that apply today to properties located in a SFHA will be reduced in the future as sea levels rise. Note that many structures currently located in a SFHA were built before these standards were required and will experience higher risk unless they are elevated. 4.2 Critical Facilities 4.2.1 Critical Facilities Inventory The list of 39 critical asset types that are required to be included in Vulnerability Assessments is defined in Section 380.093, F.S. The asset types are broken into four asset classes: • Transportation and Evacuation Routes – airports, bridges, bus terminals, ports, major roadways, marinas, rail facilities, and railroad bridges • Critical Infrastructure – wastewater treatment facilities and lift stations, stormwater treatment facilities and pump stations, drinking water facilities, water utility conveyance systems, electric production and supply facilities, solid and hazardous waste facilities, military installations, communication facilities, and disaster debris management sites • Critical Community and Emergency Facilities – schools, colleges and universities, community centers, correctional facilities, disaster recovery centers, emergency medical service facilities, hospitals, law enforcement facilities, local government facilities, logistical staging areas, affordable public housing, risk shelter inventory, and state government facilities Agenda Item # 16 Jun 2025 Page 47 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-24 • Natural, Cultural, and Historical Resources – conservation lands, parks, shorelines, surface waters, wetlands, and historical and cultural assets Critical and regionally significant assets and required background data were assembled from local, state and federal data sources. Appendix D lists the 349 identified critical assets and summarizes the asset class, asset type, dataset type, source, and data type. Figure 4-1 shows the locations of the critical assets. The GIS data for all asset types are stored in a geodatabase that meets the RFGP GIS Data Standards. Table 4-2 summarizes the number of critical and regionally significant assets that were identified by asset type. Figure 4-1 - Critical Asset Locations Agenda Item # 16 Jun 2025 Page 48 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-25 Table 4-2 Critical and Regional Significant Assets by Type Note that the City’s utility service area extends beyond the city limits to approximately Wonderwood Drive. Critical infrastructure shown on Figure 4-1 outside of the city limits are all associated with water and wastewater utility assets. As required, an elevation was assigned to each of the critical and regionally significant assets. Where data were available, building assets were assigned finished floor elevations (FFEs) from site-specific surveys, construction plans, and/or as-builts found on the St. Johns River Water Management District (SJRWMD) Environmental Resource Permit (ERP) website. Where site- Asset Type Total Number of Assets Affordable Public Housing 10 Communication Facilities 4 Community Centers 4 Conservation Lands 5 Disaster Debris Site 3 Disaster Recovery Center 1 Drinking Water Facilities 9 Emergency Operations Center 1 Fire Stations 1 Health Care Facilities 10 Historical and Cultural Assets 2 Law Enforcement Facilities 1 Lift Stations 32 Local Government Facilities 3 Logistical Staging Area 2 Parks 16 Risk Shelter Inventory 1 Roads 83 Schools 5 Shorelines 2 Stormwater Facilities 1 Solid and Hazardous Waste Facilities 2 Surface Waters 38 Waste Water Facilities 1 Wetlands 109 Total 346 Agenda Item # 16 Jun 2025 Page 49 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-26 specific FFE data were not available, FFEs were estimated using the 2018 LiDAR DEM and the asset’s building footprint. For assets not associated with buildings (i.e., parks, wetlands, surface waters, etc.), elevations were assigned based on the lowest DEM elevation within the asset footprint. Table 4-1 also summarizes the elevation data source(s) used for each asset type. 4.2.2 Critical Facilities Sensitivity Analysis The purpose of the sensitivity analysis is to measure the impact of flooding on critical and regionally significant assets, applying the data from the exposure analysis to the inventory of critical assets. Requirements for this analysis include: ▪ An evaluation of the impact of flood severity on each asset class at each flood scenario with an assignment of risk level based on the percentage and number of critical assets affected. ▪ A list of critical and regionally significant assets that are impacted by flooding. The list must be prioritized by area or immediate need and must identify which flood scenario(s) impacts each asset. For the Sensitivity Analysis, the results from the Exposure Analysis were compared to the elevations of the critical and regionally significant assets. Flood depth and/or number of expected tidal flood days was calculated for each critical asset for every flood scenario. A sensitivity level (high, medium, low) was assigned to each asset for each scenario based on the asset type and the depth of flooding or the number of expected tidal flood days. Table 1 in Appendix D shows the severity levels assigned by critical asset type. Figure 1 through Figure 25 in Appendix D show the sensitivity levels assigned to the critical assets for each flood scenario from the exposure analysis. A probability-of-failure/consequence-of-failure based methodology was utilized to rank and prioritize the vulnerable critical assets. With the sensitivity level assigned for each event as described above, a weighting factor was developed for the 25 scenarios analyzed. Flood scenarios that occur sooner and more frequently were assigned a higher weighting factor. Table 2 in Appendix D shows the exposure weighting factors assigned for the 25 scenarios. The high/medium/low (H/M/L) sensitivity levels were assigned point values of 5/3/1 respectively. The sensitivity score for each scenario was then multiplied by its respective exposure weighting factor and the highest scores from the tidal, rainfall, surge, and expected tidal flood days scenarios were totaled. The totals were then normalized by dividing by 40 to generally put scores in the 0 to 10 range. This score characterizes the probability of failure for each asset. To characterize the consequence of failure, weighting factors were developed by asset type. Each asset type was assigned a flood impact score to characterize the environmental, social, and economic impacts if that type of asset was flooded and not able to function. To weight regionally significant assets higher, assets designated as regionally significant were given a weighting factor of 2.5. Table 3 in Appendix D shows the environmental, social, and economic impact scores assigned to each asset type. Agenda Item # 16 Jun 2025 Page 50 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-27 The normalized flooding score was then multiplied by the sum of the regional significance score and the average of the three impact scores. Based on a distribution of the results, those numeric values were assigned a priority rating of highest, high, medium, low, lowest, or not vulnerable. Table 4 in Appendix D summarizes the priority ratings assigned by asset type. Appendix E shows the results of the Sensitivity Analysis by asset for tidal flooding, Appendix F for rainfall-induced flooding, and Appendix G for surge flooding. The results in the Appendix E, F, and G are sorted by the final priority rating assignment. 4.2.3 Summary of Critical Facilities Vulnerability Tables 4-3, 4-4 and 4-5 summarizes the projected vulnerability of critical facilities for Atlantic Beach for the 2050 and 2080 planning horizons. As depicted in the tables, rainfall flooding poses the highest risk for critical facilities, to include community centers, emergency operation centers, fire stations, law enforcements facilities, lift stations, roads, and schools. Agenda Item # 16 Jun 2025 Page 51 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-1 Table 4-3 Percentage of Assets Flooded by Asset Type for Tidal Flooding Scenarios Asset Type Total Number of Assets Tidal Flooding Tidal Flood Days Tidal MHHW+2' Existing Conditions Tidal MHHW+2' Int- Low 2050 Tidal MHHW+2' Int 2050 Tidal MHHW+2' Int- Low 2080 Tidal MHHW+2' Int 2080 Tidal Flood Days Existing Tidal Flood Days Int-Low 2050 Tidal Flood Days Int 2050 Tidal Flood Days Int-Low 2080 Tidal Flood Days Int 2080 Affordable Public Housing 10 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Colleges and Universities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Community Centers 4 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Conservation Lands 5 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% Day Cares 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Disaster Debris Management Sites 3 33% 33% 33% 33% 33% 33% 33% 33% 33% 33% Disaster Recovery Centers 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Emergency Operation Centers 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Fire Stations 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Health Care Facilities 10 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Historical Cultural Site 1 0% 100% 100% 100% 100% 0% 100% 100% 100% 100% Law Enforcement Facilities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Lift Stations 33 3% 6% 9% 18% 30% 3% 6% 9% 18% 30% Local Government Facilities 3 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Logistical Staging Areas 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Parks 16 50% 50% 50% 50% 56% 50% 50% 50% 50% 56% Radio Communications Towers 4 0% 25% 25% 25% 25% 0% 25% 25% 25% 25% Risk Shelter Inventory 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Roads 83 0% 0% 1% 7% 16% 0% 0% 1% 7% 16% Schools 3 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Solid and Hazardous Waste Facilities 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Surface Waters 38 47% 50% 50% 55% 66% 47% 50% 50% 55% 66% Waste Water Facilities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Water Supply Wells 6 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Water Treatment Plants 3 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Wetlands 109 83% 84% 84% 86% 90% 83% 84% 84% 86% 90% Agenda Item #16 Jun 2025Page 52 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-2 Table 4-4 Percentage of Assets Flooded by Asset Type for Rainfall Flooding Scenarios Asset Type Total Number of Assets Rainfall Inundation Rainfall 100- YR/24-HR Existing Conditions Rainfall 500- YR/24-HR Existing Conditions Rainfall 100- YR/24-HR Int- Low 2050 Rainfall 500- YR/24-HR Int- Low 2050 Rainfall 100- YR/24-HR Int 2050 Rainfall 500- YR/24-HR Int 2050 Rainfall 100- YR/24-HR Int- Low 2080 Rainfall 500- YR/24-HR Int- Low 2080 Rainfall 100- YR/24-HR Int 2080 Rainfall 500- YR/24-HR Int 2080 Affordable Public Housing 10 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Colleges and Universities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 100% Community Centers 4 0% 0% 0% 25% 0% 25% 0% 25% 25% 25% Conservation Lands 5 60% 60% 60% 60% 60% 60% 60% 60% 60% 60% Day Cares 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Disaster Debris Management Sites 3 0% 33% 33% 33% 33% 33% 33% 33% 33% 33% Disaster Recovery Centers 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Emergency Operation Centers 1 0% 0% 0% 100% 0% 100% 0% 100% 0% 100% Fire Stations 1 0% 0% 0% 100% 0% 100% 0% 100% 0% 100% Health Care Facilities 10 0% 0% 0% 10% 0% 10% 0% 20% 0% 20% Historical Cultural Site 1 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% Law Enforcement Facilities 1 0% 0% 0% 100% 0% 100% 0% 100% 0% 100% Lift Stations 33 30% 42% 42% 42% 42% 45% 42% 48% 42% 48% Local Government Facilities 3 0% 0% 0% 67% 0% 67% 0% 67% 33% 67% Logistical Staging Areas 2 0% 0% 0% 50% 0% 50% 50% 50% 50% 50% Parks 16 50% 50% 50% 50% 50% 50% 50% 50% 56% 56% Radio Communications Towers 4 0% 0% 0% 25% 0% 25% 0% 25% 25% 25% Risk Shelter Inventory 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Roads 83 45% 54% 53% 55% 53% 57% 55% 58% 55% 58% Schools 3 0% 0% 0% 67% 0% 67% 0% 67% 0% 100% Solid and Hazardous Waste Facilities 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Surface Waters 38 63% 63% 63% 63% 63% 66% 63% 66% 63% 66% Waste Water Facilities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Water Supply Wells 6 0% 0% 0% 0% 0% 0% 0% 17% 0% 17% Water Treatment Plants 3 0% 0% 0% 0% 0% 0% 0% 33% 0% 33% Wetlands 109 36% 36% 36% 36% 36% 36% 36% 36% 36% 36% Agenda Item #16 Jun 2025Page 53 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 4-3 Table 4-5 Percentage of Assets Flooded by Asset Type for Surge Flooding Scenarios Asset Type Total Number of Assets Storm Surge Flooding (SWEL) Storm Surge 100-YR Existing Conditions Storm Surge 100-YR Int-Low 2050 Storm Surge 100-YR Int 2050 Storm Surge 100-YR Int-Low 2080 Storm Surge 100-YR Int 2080 Affordable Public Housing 10 0% 0% 0% 0% 0% Colleges and Universities 1 0% 0% 0% 0% 0% Community Centers 4 0% 0% 0% 0% 0% Conservation Lands 5 100% 100% 100% 100% 100% Day Cares 2 0% 0% 0% 0% 0% Disaster Debris Management Sites 3 0% 0% 0% 0% 0% Disaster Recovery Centers 1 0% 0% 0% 0% 0% Emergency Operation Centers 1 0% 0% 0% 0% 0% Fire Stations 1 0% 0% 0% 0% 0% Health Care Facilities 10 0% 0% 0% 0% 0% Historical Cultural Site 1 100% 100% 100% 100% 100% Law Enforcement Facilities 1 0% 0% 0% 0% 0% Lift Stations 33 0% 0% 0% 0% 0% Local Government Facilities 3 0% 0% 0% 0% 0% Logistical Staging Areas 2 0% 0% 0% 0% 0% Parks 16 38% 38% 38% 50% 50% Radio Communications Towers 4 0% 0% 0% 0% 0% Risk Shelter Inventory 1 0% 0% 0% 0% 0% Roads 83 13% 20% 24% 34% 47% Schools 3 0% 0% 0% 0% 0% Solid and Hazardous Waste Facilities 2 0% 0% 0% 0% 0% Surface Waters 38 50% 58% 58% 58% 61% Waste Water Facilities 1 0% 0% 0% 0% 0% Water Supply Wells 6 0% 0% 0% 0% 0% Water Treatment Plants 3 0% 0% 0% 0% 0% Wetlands 109 84% 87% 87% 87% 88% Agenda Item #16 Jun 2025Page 54 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 5-1 Next Steps 5.1 Adaptation Planning There is good news. The City of Atlantic Beach has time plan for the future and minimize the negative impacts associated with SLR. The next step is for the City to begin an adaptation planning process. The adaptation planning process would engage stakeholders to evaluate SLR predictions and consider what actions, if any, should be taken. The Florida Department of Economic Development (DEO) has resources available to assist local governments in this process and multiple communities have already completed their adaptation plans. DEO describes the following 5 strategies for adaptation planning: 1. Protection - Protection strategies involve "hard" and "soft" structurally defensive measures to mitigate the impacts of current and future flooding, such as seawalls or beach renourishment, in order to maintain existing development. 2. Accommodation - Accommodation strategies do not act as a barrier to inundation but rather alter the design, construction, and use of structures to handle periodic flooding. Examples include elevating structures and stormwater retrofits that improve drainage or use natural areas to soak up or store water and runoff (i.e., green infrastructure). 3. Strategic Relocation - Strategic relocation involves the possible relocation of existing development to safer areas through voluntary or incentivized measures in populated, hazard prone areas that reduce the intensity of development and/or gradually increase setbacks over time. Such options usually involve the transition of vulnerable land from private to public ownership, but may also include other strategies such as transfer of development rights, purchase of development rights, and rolling easements. 4. Avoidance - Avoidance involves anticipatory actions taken to direct new development away from vulnerable lands to safer areas. Examples include land conservation, conservation easements, transfer of development rights, and increased coastal setbacks. 5. Procedural - Procedural strategies aim to generate vulnerability and adaptation information, increase awareness of vulnerabilities and adaptation options, or incorporate such information into plans or policies. Examples include vulnerability assessments, community outreach and education activities, new comprehensive plan language addressing sea level rise, and real estate disclosures. Agenda Item # 16 Jun 2025 Page 55 of 102 Coastal Vulnerability Assessment City of Atlantic Beach 6-1 References 2015 Unified Sea Level Rise Projection for Southeast Florida, Southeast Florida Regional Climate Change Compact Sea Level Rise Work Group, 2015 Climate Science Special Report: Fourth National Climate Assessment, U.S. Global Change Research Program, 2017 Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) Climate Change 2014: Synthesis Report, 2014 Adaptation Planning – Florida Department of Economic Opportunity (http://www.floridajobs.org/community-planning-and-development/programs/community- planning-table-of-contents/adaptation-planning) Global and Regional Sea Level Rise Scenarios for the U.S., NOAA Technical Report NOS CO- OPS 083, 2017 Global Sea Level Rise Scenarios for the United States, NOAA Technical Report OAR CPO-1 National Climate Assessment, 2012 Incorporating Sea Level Changes in Civil Works Programs, USACE Engineer Regulation (ER) 1100-2-8162, 2013 NOAA Tides & Currents – Water Levels (https://tidesandcurrents.noaa.gov/sltrends/) Regional Sea Level Scenarios for Coastal Risk Management Report, Coastal Assessment Regional Scenario Working Group (CARSWG) 2016 US Army Corps of Engineers (USACE) Sea Level Analysis Tool (https://www.usace.army.mil/Infrastructure-and-Installation-Resilience/Public-Tools- Developed-by-USACE/Sea-Level-Change/) Agenda Item # 16 Jun 2025 Page 56 of 102 Phase 1 Adaptation Plan Planning & Community Development Department 800 Seminole Road Atlantic Beach, FL 32233 June 2025 Agenda Item # 16 Jun 2025 Page 57 of 102 Phase 1 Adaptation Plan City of Atlantic Beach ii Table of Contents Executive Summary 1 Background 1-1 1.1 Location and History 1-1 1.2 Sea-Level Rise (SLR) Trend 1-1 1.3 Community Resilience 1-3 1.4 General Adaptation Planning 1-3 1.4.1 Protection 1-3 1.4.2 Accommodation 1-4 1.4.3 Strategic Relocation 1-4 1.4.4 Avoidance 1-4 1.4.5 Procedural 1-4 Legal Context 2-1 2.1 Comprehensive Planning 2-1 2.2 Litigation Risk 2-2 Coastal Vulnerability 3-1 3.1 Exposure 3-1 3.2 Sensitivity 3-2 3.3 Ranking 3-2 3.4 Public Input 3-3 3.5 Local Priorities 3-3 Adaptation Strategies 4-1 4.1 Range of Adaptation Strategies 4-1 4.1.1 Reducing Exposure 4-1 4.1.2 Reducing Sensitivity 4-1 4.1.3 Increasing Adaptive Capacity 4-2 4.2 Focus Areas for Adaptation 4-4 4.2.1 Citywide 4-4 4.2.2 Areas West of Mayport Road 4-4 4.2.3 Major Drainageways 4-5 4.2.4 Roadways 4-6 4.2.5 Critical Utility Infrastructure 4-6 4.2.6 Critical Public Facilities 4-6 4.3 Current Strategies and Existing Regulations 4-7 4.3.1 Existing Plans 4-7 4.3.2 Existing Development Regulations 4-7 4.3.3 Current Initiatives 4-8 4.4 Recommended Strategies for Focus Areas 4-9 4.4.1 Citywide 4-9 Agenda Item # 16 Jun 2025 Page 58 of 102 Phase 1 Adaptation Plan City of Atlantic Beach iii 4.4.2 Areas West of Mayport Road 4-11 4.4.3 Major Drainageways 4-12 4.4.4 Roadways 4-16 4.4.5 Critical Utility Infrastructure 4-17 4.4.6 Critical Public Facilities 4-18 Recommended Actions 5-1 5.1 Summary of Recommended Actions and Schedule 5-1 5.2 Monitoring and Evaluation 5-3 References 6-1 Agenda Item # 16 Jun 2025 Page 59 of 102 Phase 1 Adaptation Plan City of Atlantic Beach iv Appendices Appendix A – Inundation Scenarios and Maps Appendix B – Public Workshop Comments List of Tables Table 3-1 – Exposure of Property by Scenario ........................................................................ 3-1 Table 3-2 – Percentage of Assets Flooded by Asset Type for Tidal Flooding Scenarios ......... 3-1 Table 3-3 –Percentage of Assets Flooded by Asset Type for Rainfall Flooding Scenarios ...... 3-2 Table 3-4 – Percentage of Assets Flooded by Asset Type for Surge Flooding Scenarios ....... 3-3 Table 3-5 – Ranking of Exposed Roadway Segments ............................................................. 3-1 Table 4-1 – Comparison of Exposure Reduction Strategies .................................................... 4-1 Table 4-2 – Comparison of Sensitivity Reduction Strategies ................................................... 4-2 Table 5-1 – Summary of Recommendations and Implementation Schedule ............................ 5-1 Table 5-2 – Areas West of Mayport Road Recommended Actions & Schedule ....................... 5-2 Table 5-3 – Major Drainageways Recommended Actions & Schedule .................................... 5-2 Table 5-4 – Roadways Recommended Actions & Schedule .................................................... 5-2 Table 5-5 – Critical Utility Infrastructure .................................................................................. 5-3 Table 5-6 – Critical Public Facilities ......................................................................................... 5-3 List of Figures Figure 1-1 – Global Change in Sea Levels .............................................................................. 1-2 Figure 1-2 – Sea Level Trends at Mayport Bar Pilots Dock ..................................................... 1-3 Figure 3-1 – Critical Roadway Segment Ranking .................................................................... 3-2 Figure 4-1 – 2044 Nuisance and 100-Year Storm Flooding West of Mayport Road ................. 4-5 Figure 4-2 – Major Drainageways ........................................................................................... 4-6 Agenda Item # 16 Jun 2025 Page 60 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 1 Executive Summary Coastal communities in Florida are already experiencing the effects of sea-level rise (SLR), stronger coastal storms, and more intense precipitation events. As sea levels are projected to rise at an accelerating rate in the coming years and decades, increases in flood frequency and flood depth in coastal areas are expected, which could lead to increased flood insurance costs, market value declines, and property damage. As a low-lying coastal community bordering the Atlantic Ocean on the east and the Intracoastal Waterway to the west, Atlantic Beach is especially vulnerable to storm surge, rainfall flooding, nuisance flooding, and SLR. In 2019, Atlantic Beach completed a coastal vulnerability assessment that was updated in 2021 to include the City’s utility service area north of the City within City of Jacksonville city limits. Since then, state regulations have been introduced to standardize these assessments, State Stute 380.093 has clarified reporting requirements, and our modeling capabilities have significantly improved, resulting in the 2025 update. In this assessment, projected SLR, nuisance flooding, and 100-year recurrence interval flood risk areas were modeled for 25- and 55-year future scenarios. These models were then used to assess potential risks to property, structures, and infrastructure and to identify focus areas within the City. A vulnerability assessment such as this is a key step in the adaptation planning process as the findings are used to inform the strategies discussed in this Plan. Further, a vulnerability assessment fulfills a statutory requirement for designating Adaptation Action Areas (AAAs) and forms the scientific basis for complying with the “Peril of Flood” statutory requirement. The next step in the process is to complete an adaptation plan. An adaptation plan identifies goals and strategies to best minimize risks and establishes a process to implement those strategies. Becoming a more resilient community is not a one-time process of planning and implementing. Rather, it is a continual process that will forever be a part of the City’s future. According to the National Oceanic and Atmospheric Administration (NOAA), the ultimate goal of an adaptation plan is to create coastal communities that are organized to take action, have the tools to take action, and take action to plan for and adapt to the impacts of SLR and climate change. This Phase 1 Adaptation Plan is the result of the first iteration of the City’s adaptation planning process. This Plan contains general recommendations for adaptation strategies to be applied to exposed areas of the City as well as a recommended implementation schedule. Subsequent iterations of this living document will be completed after solicitation of public input and will contain additional objective data, more specific strategies, and updated implementation schedules as appropriate. This project was made possible by a Resilient Florida Grant Program (RFGP)provided by the Florida Department of Environmental Protection’s (FDEP) Resilient Coastlines program and a Community Development Block Grant Mitigation Program provided by the Department of Commerce. The following City of Atlantic Beach staff provided content along with technical support from Jones Edmunds & Associates, Inc.: Agenda Item # 16 Jun 2025 Page 61 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 2 Steve Swann; PE, City Engineer Amanda Askew; AICP, Neighborhoods Department Director Abrielle Genest, Principal Planner and Environmental Coordinator Agenda Item # 16 Jun 2025 Page 62 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 1-1 Background 1.1 Location and History The City of Atlantic Beach is one of three small coastal communities in northeast Florida that make up the Beaches of Jacksonville. The City is approximately 4 square miles in size with a population of around 14,000 and is located between the Atlantic Ocean on the east and the San Pablo Creek/Atlantic Intracoastal Waterway (AICW) on the west. Atlantic Beach is a near fully - developed municipality where the predominant land use is residential consisting of stable and well-established neighborhoods. As a low-lying coastal community, Atlantic Beach is especially vulnerable to flood risks as experienced during Hurricane Irma, Hurricane Matthew, Tropical Storm Nicole and the November 2015 Nor’easter. Additionally, most of the City was developed before modern stormwater regulations for flood protection, which has contributed to flooding issues in the City. Understanding these existing and potential hazards, the City, with the assistance from the Florida Department of Environmental Protection (FDEP) Resilient Coastline program, completed a vulnerability assessment in 2019 and updates in 2021 and 2025, which will inform this Adaptation Plan. 1.2 Sea-Level Rise (SLR) Trend Scientists from around the world have been studying climate change and the resulting SLR impacts for decades. Today, multiple sources of data are available to predict realistic scenarios of future sea levels and their impacts on coastal communities. These projections are generally based on global climate models (GCMs) that use assumptions regarding future human behavior with respect to greenhouse gas emissions. On average globally, the sea level has risen by approximately 8 inches since scientific recordkeeping began in 1880. This rate has increased in recent decades to a little more than an inch per decade. Global average sea level has risen by approximately 7 to 8 inches (16 to 21 cm) since 1900, with around 3 inches occurring since 1993. In addition to the global average SLR, local SLR – sometimes called relative SLR – happens at different rates in different places. Local SLR is affected by the global SLR, but also by local land motions and the effects of tides, currents, and winds. Figure 1-1 shows an increase in the global average sea level since 1880 in inches. The blue line, which shows tide-gauge data, becomes steeper in more recent decades. This indicates an increasing rate of change. The surrounding light-blue shaded area shows upper and lower 95- percent confidence intervals, and the orange line shows sea level as measured by satellites for comparison from 1993 through 2020 (US Global Change Research Program, 2017). As sea levels have risen, the incidence of nuisance flooding or sunny day flooding during spring-tide events at certain times of the year have increased five- to tenfold since the 1960s in several US coastal cities, and rates of increase at over 25 long-term gage locations on the Atlantic and Gulf coasts are accelerating. In Atlantic Beach, nuisance flooding resulting in overtopped roads is occurring now in areas of Atlantic Beach such as Dutton Island Road and We st Plaza. The closest NOAA Agenda Item # 16 Jun 2025 Page 63 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 1-2 primary tidal gauge to Atlantic Beach is at the Mayport Bar Pilot’s Dock (NOAA tide gauge No. 8720218) near the ferry slip. Figure 1-2 depicts the relative change in sea level at the Mayport Bar Pilot’s Dock over the 90-year history of this station. The current local rate of sea-level change is approximately 1 inch every decade (https://tidesandcurrents.noaa.gov/sltrends/). Although the rate of change in SLR is uncertain, there is no uncertainty that sea level is rising in our area. As sea levels rise, incidents of nuisance flooding will increase , and flooding due to severe weather events will affect larger areas of the City. To aid in planning and assessing the City’s potential vulnerability under future scenarios with higher sea levels, the City conducted a rigorous technical analysis to determine what those effects may be and how they will impact residents and critical infrastructure. Figure 1-1 – Global Change in Sea Levels Agenda Item # 16 Jun 2025 Page 64 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 1-3 Figure 1-2 – Sea Level Trends at Mayport Bar Pilots Dock 1.3 Community Resilience Resiliency is the ability to collaboratively prepare for, prevent, absorb, recover from, and more equitably adapt for damage from chronic stressors (i.e., aging infrastructure and SLR) and adverse events (i.e., hurricanes, coastal storms, and flooding). Resiliency in coastal communities such as Atlantic Beach is especially important due to high population densities and coastal hazards. A community that is informed and prepared will be more resilient and have a greater opportunity to rebound quickly after an adverse event. 1.4 General Adaptation Planning An adaptation plan is a sound and sensible method for Florida’s coastal communities to develop and enhance their strategies for protecting coastal populations and infrastructure. An adaptation plan identifies goals and strategies to best minimize risks and establishes a process to implement those strategies. According to NOAA, the ultimate goal of an adaptation plan is to create coastal communities that are organized to take action, have the tools to take action, and take action to plan for and adapt to the impacts of SLR and climate change. A community can select from a wide range of strategies in the following categories: Protection, Accommodation, Strategic Relocation, Avoidance, and Procedural. 1.4.1 Protection Protection strategies involve both hard and soft (gray or green) structurally defensive measures to mitigate impacts of current and future flooding to maintain existing development. Examples such as seawalls, revetments, and levees are examples of hard or gray protection strategies, while examples such as beach renourishment and living shorelines are examples of soft or green strategies. Agenda Item # 16 Jun 2025 Page 65 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 1-4 1.4.2 Accommodation Accommodation strategies do not act as a barrier to inundation but rather alter the design, construction, and use of structures to handle periodic flooding. Examples include elevating structures above flood stage and stormwater retrofits that improve drainage or use natural features to soak up or store water and runoff (i.e., green infrastructure). 1.4.3 Strategic Relocation Strategic relocation strategies consist of relocating existing development to safer areas through voluntary or incentivized measures. Examples include redevelopment regulations, home buyout programs, and rolling easements. 1.4.4 Avoidance Avoidance strategies involve guiding new development away from vulnerable areas to safer, more appropriate areas. Such measures include transfer of development rights, land conservation, and increased setbacks/buffers. 1.4.5 Procedural Procedural strategies aim to generate vulnerability and adaptation information, increase awareness of vulnerabilities and adaptation options, or incorporate such information into plans or policies. Examples include vulnerability assessments, community outr each and education activities, new comprehensive plan language addressing SLR, and real estate disclosures. Agenda Item # 16 Jun 2025 Page 66 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 2-1 Legal Context 2.1 Comprehensive Planning Florida Statutes require every municipality in Florida to maintain a comprehensive plan, which shall provide the principles, guidelines, standards and strategies for the orderly and balanced future economic, social, physical, environmental, and fiscal development of the area… (Fla. Stat. 163.3177(1)). Comprehensive plans contain different elements, some of which are required by the state including a Future Land Use Element and a Conservation and Coastal Management Element. The Future Land Use Element, according to Florida Statute, shall establish the long-term end toward which land use programs and activities are ultimately directed. This and several additional statutes provide a solid legal basis for adding to or revising the Goals, Objectives, and Policies of the Future Land Use Element for adaptation purposes. For example, statutory provisions discouraging urban sprawl address protecting and conserving natural resources such as wetlands, beaches, and floodplains. The Conservation and Coastal Management Element is required by Florida Statute to address SLR. Senate Bill (SB) 1094, enacted in 2015, requires coastal localities to include a redevelopment component within this element and specified that the principles, strategies, and engineering solutions described in the redevelopment component must address flood risk arising from several sources, including SLR. The redevelopment component is the logical place to include guidelines and restrictions that do not take effect until they are triggered by an event, such as flooding of a particular depth. SB 1094’s requirements provide communities with a good reason to adopt such measures and also with a potent tool for inoculating restrictions on development against takings claims. Comprehensive plans must be informed by analysis of relevant and appropriate data, which must be gathered from professionally accepted sources or generated by the local government so long as the methodologies for gathering data are professionally accepted. Florida law also requires that changes to the comprehensive plan must be supported by analysis and that such analysis must reflect reasonable and proportionate applications of the data cited. Scientific certainty is not a required feature of supporting data or their analysis. This flexibility means that the City’s Coastal Vulnerability Assessment will not operate as a floor or ceiling for planning purposes. If the City refers to the Vulnerability Assessment as supporting particular language or parameters, the City would only need to articulate a logical link between the Assessment and the action. Planning timeframes also changed under SB 1094 in 2015 by allowing localities to incorporate additional planning periods for specific components or projects rather than be limited to the 5- and 10-year periods previously required. This change has vital implications for plans involving assets or facilities whose useful life exceeds 10 years and whose location makes them vulnerable to SLR. Local governments can now ensure SLR projections inform their plans for such infrastructure designs, planning restrictions, and capital investments. The University of Florida’s Agenda Item # 16 Jun 2025 Page 67 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 2-2 Conservation Clinic drafted model language to ensure adaptation planning employs an appropriate timeframe: Policy 1.2.1: [Planning Horizon] Utilize a (__) year planning horizon when considering the adoption of any protection, accommodation, and managed retreat strategy within the City/County. The 2011 Comprehensive Planning Act authorized localities to designate Adaptation Action Areas (AAAs), which are locations that experience coastal flooding due to extreme high tides and storm surge and that are vulnerable to the related impacts of rising sea levels. This designation is to prioritize funding and planning in these vulnerable areas. 2.2 Litigation Risk As SLR shifts the operations of local government, the result is potentially a double -edged sword situation regarding litigation risk. If local governments act to address SLR, they could be sued by property owners claiming injury from limitations on the property’s use or adverse effects to property values. On the other hand, local governments could also be sued for faili ng to address SLR. Takings Law protects private-property owners from government actions that fail to provide them with just compensation for the condemnation or appropriation of their real property or for regulations that deprive their real property of all or almost all of its use and economic value. In Florida, two sources of Takings Law are available: the Fifth Amendment to the US Constitution and the Bert Harris Private Property Rights Protection Act. Takings Law can be complex and unpredictable in its application to particular cases and the source of highly fact-specific legal disputes. Local governments will face challenges legally when implementing particular adaptation strategies. However, many state and local governments already use a multitude of strategies to manage development in their communities. By using existing strategies in new ways, governments may be able to minimize the complexities of adaptation. Agenda Item # 16 Jun 2025 Page 68 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 3-1 Coastal Vulnerability Given the location of the City of Atlantic Beach between the AICW and the Atlantic Ocean and its relatively low elevation, certain areas of the City are particularly vulnerable to SLR. The City of Atlantic Beach Coastal Vulnerability Assessment was completed in June 2019 and updated in April 2021 to include City-owned water and wastewater infrastructure outside the City limits and June 2025 to comply with data standards set in FS 380.093. The Vulnerability Assessment identified areas of the City that may be subject to increased flooding due to SLR. The Coastal Vulnerability Assessment also identified assets such as buildings, residences, and critical infrastructure in these areas that could be impacted. The following sections of this report describe the exposure of these assets to SLR as well as their sensitivity to this exposure. 3.1 Exposure For coastal flooding, exposure is defined as the impact to an asset from extreme coastal storm flooding and nuisance flooding using the SLR scenarios identified in the Coastal Vulnerability Assessment. Extreme coastal storm flooding in the context of this analysis are 100-year storm events caused by a temporary increase in water levels due to a combination of high tides, storm surge, waves, and rainfall. Nuisance flooding is defined as water levels expected at least once per year that are 1 foot greater than the mean higher high-water level. Appendix A to this Plan provides maps depicting exposure under these conditions for current and future scenarios. The coastal flooding analysis completed for the Coastal Vulnerability Assessment included flooding from storm surge as well as rain-induced flooding for predicted sea levels in 25, 50, and 100 years. The results of this analysis identified the potential exposure of property and critical infrastructure within the study area to flooding during a 100-year storm event. Table 3-1 provides the results of the exposure analysis for the 25- and 55-year scenarios. Table 3-1 – Exposure of Property by Scenario 2050 Intermediate- Low Scenarios Number of Parcels Impacted (% of All Parcels) Number of Buildings on Impacted Parcels Land Value of Impacted Parcels Building Value of Impacted Parcels Taxable Value of Impacted Parcels Nuisance Flooding 625 (10%) 738 $290,351,970 $269,609,632 $282,169,878 Storm Surge 701 (11%) 803 $234,070,885 $224,527,108 $230,900,463 Agenda Item # 16 Jun 2025 Page 69 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 3-2 2050 Intermediate Scenarios Number of Parcels Impacted (% of All Parcels) Number of Buildings on Impacted Parcels Land Value of Impacted Parcels Building Value of Impacted Parcels Taxable Value of Impacted Parcels Nuisance Flooding 779 (12%) 667 $303,272,940 $280,466,531 $293,224,628 Storm Surge 776 (12%) 887 $255,644,673 $241,941,745 $248,670,883 2080 Intermediate- Low Scenarios Number of Parcels Impacted (% of All Parcels) Number of Buildings on Impacted Parcels Land Value of Impacted Parcels Building Value of Impacted Parcels Taxable Value of Impacted Parcels Nuisance Flooding 842 (13%) 947 $360,909,500 $326,838,789 $340,582,741 Storm Surge 1,291 (21%) 1,200 $420,541,921 $356,443,699 $365,651,140 2080 Intermediate Scenarios Number of Parcels Impacted (% of All Parcels) Number of Buildings on Impacted Parcels Land Value of Impacted Parcels Building Value of Impacted Parcels Taxable Value of Impacted Parcels Nuisance Flooding 1,276 (20%) 1167 $489,165,039 $424,150,388 $439,807,776 Storm Surge 1,736 (27%) 1,833 $707,341,778 $589,529,782 $605,611,756 3.2 Sensitivity Although the assets discussed above will potentially be exposed to flooding, some will be more sensitive to exposure than others. In this context, sensitivity is how assets identified in the exposure analysis respond or function during and after a flood impact. For example, a sewer pump station can be sensitive to flood waters if the electrical components become inundated, while a roadway that is flooded is less likely to suffer damage and is therefore less sensitive. 3.3 Ranking The Coastal Vulnerability Assessment mapped critical assets within the City as well as water and wastewater assets that the City of Atlantic Beach owns and operates, which are outside the City limits. Tables 3-2, 3-3, and 3-4 were developed from this mapping data and summarize the projected vulnerability of critical facilities for the 2050 and 2080 planning horizons. The degree of exposure of each asset was then combined with a qualitative assessment of the sensitivity and consequence of flooding of each exposed asset based on considerations unique to each asset category. The resulting matrix and ranking of critical assets are depicted in Table 3-5. Figure 3-2 graphically depicts the ranking of each critical roadway section identified in Table 3-5. Agenda Item # 16 Jun 2025 Page 70 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 3-1 Table 3-2 – Percentage of Assets Flooded by Asset Type for Tidal Flooding Scenarios Asset Type Total Number of Assets Tidal Flooding Tidal Flood Days Tidal MHHW+2' Existing Conditions Tidal MHHW+2' Int- Low 2050 Tidal MHHW+2' Int 2050 Tidal MHHW+2' Int- Low 2080 Tidal MHHW+2' Int 2080 Tidal Flood Days Existing Tidal Flood Days Int-Low 2050 Tidal Flood Days Int 2050 Tidal Flood Days Int-Low 2080 Tidal Flood Days Int 2080 Affordable Public Housing 10 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Colleges and Universities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Community Centers 4 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Conservation Lands 5 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% Day Cares 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Disaster Debris Management Sites 3 33% 33% 33% 33% 33% 33% 33% 33% 33% 33% Disaster Recovery Centers 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Emergency Operation Centers 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Fire Stations 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Health Care Facilities 10 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Historical Cultural Site 1 0% 100% 100% 100% 100% 0% 100% 100% 100% 100% Law Enforcement Facilities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Lift Stations 33 3% 6% 9% 18% 30% 3% 6% 9% 18% 30% Local Government Facilities 3 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Logistical Staging Areas 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Parks 16 50% 50% 50% 50% 56% 50% 50% 50% 50% 56% Radio Communications Towers 4 0% 25% 25% 25% 25% 0% 25% 25% 25% 25% Risk Shelter Inventory 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Roads 83 0% 0% 1% 7% 16% 0% 0% 1% 7% 16% Schools 3 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Solid and Hazardous Waste Facilities 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Surface Waters 38 47% 50% 50% 55% 66% 47% 50% 50% 55% 66% Waste Water Facilities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Water Supply Wells 6 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Water Treatment Plants 3 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Wetlands 109 83% 84% 84% 86% 90% 83% 84% 84% 86% 90% Agenda Item #16 Jun 2025Page 71 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 3-2 Table 3-3 –Percentage of Assets Flooded by Asset Type for Rainfall Flooding Scenarios Asset Type Total Number of Assets Rainfall Inundation Rainfall 100- YR/24-HR Existing Conditions Rainfall 500- YR/24-HR Existing Conditions Rainfall 100- YR/24-HR Int- Low 2050 Rainfall 500- YR/24-HR Int- Low 2050 Rainfall 100- YR/24-HR Int 2050 Rainfall 500- YR/24-HR Int 2050 Rainfall 100- YR/24-HR Int- Low 2080 Rainfall 500- YR/24-HR Int- Low 2080 Rainfall 100- YR/24-HR Int 2080 Rainfall 500- YR/24-HR Int 2080 Affordable Public Housing 10 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Colleges and Universities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 100% Community Centers 4 0% 0% 0% 25% 0% 25% 0% 25% 25% 25% Conservation Lands 5 60% 60% 60% 60% 60% 60% 60% 60% 60% 60% Day Cares 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Disaster Debris Management Sites 3 0% 33% 33% 33% 33% 33% 33% 33% 33% 33% Disaster Recovery Centers 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Emergency Operation Centers 1 0% 0% 0% 100% 0% 100% 0% 100% 0% 100% Fire Stations 1 0% 0% 0% 100% 0% 100% 0% 100% 0% 100% Health Care Facilities 10 0% 0% 0% 10% 0% 10% 0% 20% 0% 20% Historical Cultural Site 1 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% Law Enforcement Facilities 1 0% 0% 0% 100% 0% 100% 0% 100% 0% 100% Lift Stations 33 30% 42% 42% 42% 42% 45% 42% 48% 42% 48% Local Government Facilities 3 0% 0% 0% 67% 0% 67% 0% 67% 33% 67% Logistical Staging Areas 2 0% 0% 0% 50% 0% 50% 50% 50% 50% 50% Parks 16 50% 50% 50% 50% 50% 50% 50% 50% 56% 56% Radio Communications Towers 4 0% 0% 0% 25% 0% 25% 0% 25% 25% 25% Risk Shelter Inventory 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Roads 83 45% 54% 53% 55% 53% 57% 55% 58% 55% 58% Schools 3 0% 0% 0% 67% 0% 67% 0% 67% 0% 100% Solid and Hazardous Waste Facilities 2 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Surface Waters 38 63% 63% 63% 63% 63% 66% 63% 66% 63% 66% Waste Water Facilities 1 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% Water Supply Wells 6 0% 0% 0% 0% 0% 0% 0% 17% 0% 17% Water Treatment Plants 3 0% 0% 0% 0% 0% 0% 0% 33% 0% 33% Wetlands 109 36% 36% 36% 36% 36% 36% 36% 36% 36% 36% Agenda Item #16 Jun 2025Page 72 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 3-3 Table 3-4 – Percentage of Assets Flooded by Asset Type for Surge Flooding Scenarios Asset Type Total Number of Assets Storm Surge Flooding (SWEL) Storm Surge 100-YR Existing Conditions Storm Surge 100-YR Int-Low 2050 Storm Surge 100-YR Int 2050 Storm Surge 100-YR Int-Low 2080 Storm Surge 100-YR Int 2080 Affordable Public Housing 10 0% 0% 0% 0% 0% Colleges and Universities 1 0% 0% 0% 0% 0% Community Centers 4 0% 0% 0% 0% 0% Conservation Lands 5 100% 100% 100% 100% 100% Day Cares 2 0% 0% 0% 0% 0% Disaster Debris Management Sites 3 0% 0% 0% 0% 0% Disaster Recovery Centers 1 0% 0% 0% 0% 0% Emergency Operation Centers 1 0% 0% 0% 0% 0% Fire Stations 1 0% 0% 0% 0% 0% Health Care Facilities 10 0% 0% 0% 0% 0% Historical Cultural Site 1 100% 100% 100% 100% 100% Law Enforcement Facilities 1 0% 0% 0% 0% 0% Lift Stations 33 0% 0% 0% 0% 0% Local Government Facilities 3 0% 0% 0% 0% 0% Logistical Staging Areas 2 0% 0% 0% 0% 0% Parks 16 38% 38% 38% 50% 50% Radio Communications Towers 4 0% 0% 0% 0% 0% Risk Shelter Inventory 1 0% 0% 0% 0% 0% Roads 83 13% 20% 24% 34% 47% Schools 3 0% 0% 0% 0% 0% Solid and Hazardous Waste Facilities 2 0% 0% 0% 0% 0% Surface Waters 38 50% 58% 58% 58% 61% Waste Water Facilities 1 0% 0% 0% 0% 0% Water Supply Wells 6 0% 0% 0% 0% 0% Water Treatment Plants 3 0% 0% 0% 0% 0% Wetlands 109 84% 87% 87% 87% 88% Agenda Item #16 Jun 2025Page 73 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 3-1 Table 3-5 – Ranking of Exposed Roadway Segments Vulnerability Rating Total Roadway Length (ft.)High 5,079 MAIN ST A1 949 1 Low High 16,230 MAIN ST A2 517 8 Moderate-High Moderate-High 16,230 MAIN ST A3 184 10 High Moderate 3,253 MAIN ST A4 326 6 Moderate Moderate-Low 10,219 MAIN ST A5 691 9 High Low 15,465 MAIN ST A6 695 7 Moderate-High MAIN ST A7 684 6 Moderate MAIN ST A8 696 8 Moderate-High MAIN ST A9 688 6 Moderate DUTTON DR B1 650 6 Moderate DUTTON DR B2 1719 1 Low CHURCH RD B3 425 8 Moderate-High CHURCH RD B4 925 10 High DUTTON DR B5 647 1 Low LEVY RD C1 244 8 Moderate-High LEVY RD C2 250 6 Moderate LEVY RD C3 773 4 Moderate-Low LEVY RD C4 2165 1 Low W PLAZA D1 861 1 Low PLAZA DR E1 443 1 Low PLAZA DR E2 549 8 Moderate-High PLAZA DR E3 2427 1 Low PLAZA DR E4 328 4 Moderate-Low PLAZA DR E5 624 8 Moderate-High PLAZA DR E6 2443 10 High PLAZA DR E7 205 1 Low SEMINOLE RD F1 3586 1 Low SEMINOLE RD F10 969 8 Moderate-High SEMINOLE RD F11 213 5 Moderate SEMINOLE RD F12 437 4 Moderate-Low SEMINOLE RD F13 809 8 Moderate-High SEMINOLE RD F14 931 4 Moderate-Low SEMINOLE RD F2 836 10 High SEMINOLE RD F3 1660 1 Low SEMINOLE RD F4 442 6 Moderate SEMINOLE RD F5 803 1 Low SEMINOLE RD F6 761 4 Moderate-Low SEMINOLE RD F7 909 8 Moderate-High SEMINOLE RD F8 741 4 Moderate-Low SEMINOLE RD F9 619 8 Moderate-High SELVA MARINA DR G1 1045 8 Moderate-High SELVA MARINA DR G2 2967 4 Moderate-Low SELVA MARINA DR G3 6103 8 Moderate-High SELVA MARINA DR G4 2096 4 Moderate-Low SHERRY DR H1 2025 8 Moderate-High SHERRY DR H2 1185 4 Moderate-Low Road Name Segment ID Segment Length Vulnerability Rating Flood Exposure Commented [AG1]: Working on update Agenda Item # 16 Jun 2025 Page 74 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 3-2 Figure 3-1 – Critical Roadway Segment Ranking Agenda Item # 16 Jun 2025 Page 75 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 3-3 3.4 Public Input In 2019, the City conducted five public meetings during the development of the Coastal Vulnerability Assessment to discuss the technical approach to assessing vulnerability, present the findings of the assessment, and to solicit public comments and concerns relating to current and future coastal flooding. The City conducted a public meeting regarding adaptation planning and resiliency on April 6 and May 24, 2021, to solicit input from the public and respond to comments and concerns. Input from the City’s Environmental Stewardship Committee was solicited at their April 14 meeting and the preliminary findings were presented to this group on May 12 and June 2. Input from all meetings have been incorporated into the plan. In addition to local City of Atlantic Beach public meetings regarding vulnerability and adaptation planning, City staff have worked closely with the City of Jacksonville (COJ) and have participated in the City’s Adaptation Action Area Working Group, Storm Resilience and Infrastructure Development Review Committee, and the City Council Special Committee on Resilience. 3.5 Local Priorities The adopted 2021 priorities of the City Commission relating to adaptation planning include the following: • Continuing efforts to understand the potential impacts of local SLR and work towards improving community resilience. • Update/adopt a long-term capital improvement plan (CIP) to include adaptation, resiliency, and stormwater. • Ensure equitable spending throughout the community. • Continue to foster productive partnerships with neighboring municipalities and state and local agencies. The City is also actively working to protect natural areas that may improve storm defenses and supports the continued reauthorization of the Duval County Shore Protection Project (DCSPP) that results in periodic beach renourishment. Commented [AG2]: Insert language about 2025 public meetings Agenda Item # 16 Jun 2025 Page 76 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-1 Adaptation Strategies 4.1 Range of Adaptation Strategies Adaptation strategies can be implemented through regulations, policies, or capital projects and integrated into existing or new plans such as comprehensive plans, post-disaster redevelopment plans, CIPs, and in this case, adaptation plans. Adaptation strategies can be implemented to reduce exposure, reduce sensitivity, or increase adaptive capacity. The following sections describe these adaptation strategy categories and provide examples of general strategies within each category. 4.1.1 Reducing Exposure In the context of SLR, exposure refers to the likelihood and timing of when an asset might experience flooding due to the combination of rising sea levels and extreme rainfall and/or coastal surge events. The goal of exposure-reducing adaptation strategies is to reduce or eliminate the chances of an asset experiencing flooding in the future. This requires removing the asset from the future floodplain or altering the drainage system to limit future water levels during extreme events. Table 4-1 provides a qualitative comparison of common strategies that could be effective for reducing asset exposure to future flooding in the City. Table 4-1 – Comparison of Exposure Reduction Strategies Adaptation Strategy Implementation Cost Environmental Impact Societal Impact Construction Feasibility Service Life Retreat from Vulnerable Areas Land Acquisition/Conservation Seawall Improvements Stormwater Improvements (i.e., check valves, dams, pumps) Raising Critical Infrastructure (i.e., roads, buildings) Coastal Dune Maintenance Marsh/Vegetative Buffer Maintenance *Note: Green shaded boxes indicate strategies with lower costs, minimal environmental/societal impacts, relatively simple implementation, or longer service life. Yellow shaded boxes indicate strategies with moderate costs, some environmental/societal impacts, complex but feasible implementation, or moderate service life. Red shaded boxes indicate strategies with high costs, significant environmental/societal impacts, extremely complex, or short service life. 4.1.2 Reducing Sensitivity Sensitivity refers to the degree to which an asset’s functionality is affected by exposure to a hazard. In this case, the hazard is flooding and the goal of sensitivity -reducing adaptation Agenda Item # 16 Jun 2025 Page 77 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-2 strategies is to reduce or eliminate impacts that flooding has on an asset’s ability to function during or immediately after flooding. Table 4-2 qualitatively compares common strategies that could be effective for reducing asset sensitivity to future flooding in the City. Table 4-2 – Comparison of Sensitivity Reduction Strategies Adaptation Strategy Implementation Cost Environmental Impact Societal Impact Construction Feasibility Service Life Flood Proofing Water/Sewer Infrastructure Flood Proofing Emergency Service Operations (Police, Fire, City Hall) Flood Proofing Businesses and Homes Flood Recovery Strategies to Reduce Flood Durations Backup Power Generation for Critical Services (Water, Sewer, Emergency Services) *Note: Green shaded boxes indicate strategies with lower costs, minimal environmental/societal impacts, relatively simple implementation, or longer service life. Yellow shaded boxes indicate strategies with moderate costs, some environmental/societal impacts, complex but feasible implementation, or moderate service life. Red shaded boxes indicate strategies with high costs, significant environmental/societal impacts, extremely complex, or short service life. 4.1.3 Increasing Adaptive Capacity Adaptive capacity is the ability to adjust to or live with the impacts of SLR and changes in extreme storm events. The adaptive capacity of existing infrastructure is often fairly confined to its inherent ability to be adjusted, so increasing the adaptive capacity of existing infrastructure is challenging. Strategies for increasing the adaptive capacity of a community are forward-looking and involve policies, regulations, and strategies to enhance the adaptability of a community. The following are examples of strategies to enhance adaptive capacity: • Public Outreach and Education – As residents become more aware of future SLR and its associated flood risks, they will be more likely to support local adaptation efforts and will have the opportunity to make educated decisions that have positive impacts on the adaptability of the community. • CIP – Local governments may choose to consider future flooding risks when developing projects in their CIP or discourage investment in projects that may be vulnerable to flood risks. The local government may also discontinue maintenance and repairs to infrastructure that is repetitively damaged and relocate or retrofit existing infrastructure to be more flood resilient. • Pursuing Funding for Adaptation Projects – Implementing adaptation strategies can be very expensive. Several federal and state grant funding programs exist that can provide funds for implementing adaptation strategies. Agenda Item # 16 Jun 2025 Page 78 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-3 • Transfer of Development Rights (TDR) – This strategy is meant to limit or reduce development within vulnerable areas by allowing one property owner to sever development rights in exchange for compensation from another property owner who would like their development rights to increase. The receiving area is then allowed to have increased density or dwelling units per acre. A TDR program serves as an incentive for a property owner to avoid developing on vulnerable property by providing compensation for lost privileges. • Cluster Development – Cluster development encourages developers to concentrate development in upland/desirable areas on a tract of land while preserving/avoiding vulnerable areas, which maximizes protection of future structures, preserves vulnerable areas, and often saves developers money. • Setbacks and Buffers – Setbacks and buffers are building restrictions that establish a distance from a boundary line where landowners are prohibited from building structures. These are regulatory tools that can be established through zoning and floodplain codes or conservation easements and serve to protect existing or new structures and inhabitants by allowing inland migration of shorelines and preservation of wetlands, dunes, estuaries, and other environmentally sensitive areas. • Conservation Easements – A conservation easement is a strategy used by local governments for the permanent conservation of private lands by placing a limitation on the uses and/or allowable amount of development on a property to protect its associated resources while still allowing the owner to live, retain, and develop the property with limited use. The easement can apply to all or a portion of a property. Usually, a conservation easement preserves a portion of property in its natural state. • Floodplain Regulations – Floodplain regulations are a tool that a coastal community could amend to impose additional restrictions on development in floodplains above the National Flood Insurance Program (NFIP) minimum standards, such as use restrictions within the 100-year floodplain areas (only allow limited residential, recreational, or agricultural uses), and/or impose design requirements in the 500-year floodplain areas that are currently not required (elevation requirements). • Building Codes and Standards – Building codes establish minimum requirements for building construction. Under the Florida Building Code Act, all local codes were replaced by the Florida Building Code in 2002. However, local governments may adopt more stringent regulations where local conditions warrant. Additional regulations governing construction include flood-protection regulations pursuant to NFIP and the state Coastal Construction Control Line (CCCL) permitting standards. A coastal community may look into applying flood-resistant code standards to currently unregulated areas that may be vulnerable to flooding in the future, such as the 500-year floodplain. • Redevelopment Standards – Redevelopment standards are regulatory tools a community can use to limit, or even in some cases prohibit, what is allowed to be rebuilt on a property that has been damaged or destroyed by natural hazards. Communities can limit redevelopment of repetitive loss structures and/or other storm-damaged structures in highly vulnerable areas. Agenda Item # 16 Jun 2025 Page 79 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-4 • Real Estate Disclosures – Governmental bodies (e.g., state or local agencies) could compile data, erosion maps, inundation models, and other relevant information and make this information accessible to potential property buyers and developers. Governments could require sellers to disclose to potential buyers that a property is in an area vulnerable to flooding. 4.2 Focus Areas for Adaptation Predicted SLR over the next 25 years has a fair degree of certainty and less certainty over a 50-year time horizon. 100-year predictions in SLR are extremely uncertain. From a planning perspective and given increasing uncertainty over time, the City’s adaptation planning efforts will focus on the 25-year time horizon with consideration given to the 50-year predictions. Based on the exposure and sensitivity analyses over these timeframes , the focus areas identified for adaptation planning are provided below. 4.2.1 Citywide The City of Atlantic Beach is considered by COJ to be in an AAA. As discussed in Section 2.1, the 2011 Comprehensive Planning Act authorized localities to designate AAAs, which are locations that experience coastal flooding due to extreme high tides and storm surge and that are vulnerable to the related impacts of rising sea levels. COJ opted to define AAAs in Duval County as areas that are subject to inundation from a 500-year flood event or a Category 3 hurricane storm surge. The NOAA predicts that virtually all of the City of Atlantic Beach could be inundated by a Category 3 storm; hence, the entire city is considered to be in an AAA. Although no return interval is assigned to a Category 3 storm, unlike a 100-year flood event, the entire community can still be considered to have potential exposure. Accordingly, all of the City of Atlantic Beach is considered to be a focus area for adaptation primarily from a planning and policy perspective. 4.2.2 Areas West of Mayport Road As indicated by the future 100-year flood maps shown in Figure 4.2, many residential and commercial areas west of Mayport Road are predicted to be impacted from rising sea levels. These areas are expected to be subject to the chronic condition of nuisance flooding as well an increasing likelihood of inundation due to storm surge and rainfall-induced flooding during a 100-year storm event. Figure 4-2 depicts the expected extent of flooding due to the 100-year storm event in 2044. Agenda Item # 16 Jun 2025 Page 80 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-5 Figure 4-1 – 2044 Nuisance and 100-Year Storm Flooding West of Mayport Road 4.2.3 Major Drainageways East of Mayport Road, minimizing the extent and duration of flood events depends largely on the ability of the major drainageways to manage the stormwater runoff discharging into them. Adaptation measures will be required to ensure that the major drainageways function properly and will not be adversely impacted by rising sea levels. Figure 4-2 shows that the major drainageways serving the City include Hopkins Creek, Sherman Canal, Puckett Creek, and Sherman Creek. Commented [AG3]: Insert updated map Agenda Item # 16 Jun 2025 Page 81 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-6 Figure 4-2 – Major Drainageways 4.2.4 Roadways As discussed in Section 3, many of the major ingress and egress routes from the City may be affected by rising sea levels. These roadways will be considered a focus area for adaptation planning. The two busiest roads in the City are Mayport Road and Atlantic Boulevard. Both roadways are managed by the Florida Department of Transportation (FDOT), not the City of Atlantic Beach. 4.2.5 Critical Utility Infrastructure Critical infrastructure that will be a focus area for adaptation planning to include numerous lift stations, two of the City’s water plants, and four potable water wells. 4.2.6 Critical Public Facilities Public facilities expected to be exposed to future flooding conditions will also be focus areas for adaptation planning efforts. These include City Hall, the Police and Fire Departments, and several of the City’s community centers. Agenda Item # 16 Jun 2025 Page 82 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-7 4.3 Current Strategies and Existing Regulations Assessing existing strategies and regulations is recommended by the FDEP before identifying adaptation strategies and recommendations. This includes looking at the City’s current plans, development regulations, and other initiatives that may be used or modified for adaptation purposes. 4.3.1 Existing Plans Coastal Vulnerability Assessment This assessment used existing and projected conditions to model 25-, 50-, and 100-year scenarios for SLR and future flood hazards. The models were then used to identify vulnerable areas, properties, and infrastructure. 2018 Stormwater Master Plan Update This update built on the previous 1995, 2002, and 2012 plans and modeled existing and projected hydrologic conditions within the City and includes recommended stormwater improvement projects in identified locations. 2045 Comprehensive Plan In 2019, the City updated the Comprehensive Plan to comply with the Peril of Flood statute, which required local governments to incorporate SLR planning into their redevelopment policies. In addition, the plan contains numerous goals, objectives, and policies related to adaptation. 4.3.2 Existing Development Regulations Finished Floor Elevation (FFE) All lots and building sites shall be developed so that habitable space is constructed at a minimum FFE of 8.5 feet above mean sea level or with 2.5 feet of freeboard (above the base flood elevation), whichever is greater. Base Flood Elevations Development that encroaches into a regulated floodway must demonstrate that the development will not cause any increase in base flood elevations. Floodplain Storage Development within the 100-year floodplain must create storage onsite to mitigate for any filling of volume onsite to accomplish no net loss of storage. Onsite Storage of Stormwater Development that exceeds 50 percent of the market value of all improvements or which increases the impervious surface on a site by more than 250 square feet must provide onsite storage of stormwater. Agenda Item # 16 Jun 2025 Page 83 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-8 Impervious Surface Area In 2019, the maximum impervious surface area for properties within residential zoning districts was reduced from 50 to 45 percent. Grading and Drainage All development sites must be graded so that stormwater drains to the adjacent street, existing natural element, or a City drainage structure after meeting on-site stormwater storage requirements. Except as required to meet coastal construction codes or as required to meet applicable flood zone or stormwater regulations, the elevation or topography of a development site shall not be altered. Wetland Mitigation Any impacted wetlands on a development site must be replaced elsewhere on the site or within the City so that no net loss of jurisdictional wetlands occurs within the City. Wetland Buffer New development must maintain a 50-foot buffer from jurisdictional wetlands adjacent to water bodies connected to the Intracoastal Waterway and a 25-foot buffer from other jurisdictional wetlands. This buffer is reduced to 25 feet for single-family lots platted before 2002. Special Planned Area (SPA) An SPA zoning district may be applied for or required by the City where a proposed development has unique characteristics or special environmental features. This zoning district provides flexibility and creates opportunities for preservation (i.e., cluster development). 4.3.3 Current Initiatives Federal Emergency Management Agency’s (FEMA’s) Community Rating System (CRS) The City participates in the CRS program, which provides reductions in flood insurance premiums for cities that implement activities that exceed the minimum criteria for FEMA’s NFIP. Leadership in Energy and Environmental Design (LEED) Certification The City of Atlantic Beach became LEED for Cities certified in 2019. Cities with this certification aim to ensure a more sustainable future by creating a healthier environment. Urban Forestry Since 2019, over 450 trees have been planted in public spaces throughout the City. Additionally, the City is working to strengthen its tree protection ordinance to preserve and regenerate the urban canopy. Agenda Item # 16 Jun 2025 Page 84 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-9 Street Sweeping and Stormwater Inlet Cleaning Street sweeping and inlet cleaning help reduce localized flooding by removing debris that blocks drainage infrastructure. Vulnerable Property Acquisition Multiple properties have been purchased by the City over the years for preservation purposes including the Tide Views, Dutton Island, and River Branch Preserves. Recently, the City purchased Selva Preserve and an approximately 2-acre parcel west of Lily Street providing preservation of wetlands, maintenance of stormwater storage capacity, and storm-surge protection for adjacent properties. Duval County Shore Protection Project (DCSPP) The DCSPP, which is the federal program established for beach renourishment, is critical to maintenance and restoration of beach and dune systems, providing protection to the Atlantic Ocean coastline in Duval County. 4.4 Recommended Strategies for Focus Areas The following adaptation strategies have been developed for the identified vulnerable focus areas within the study area. These recommendations and associated timeframes are based on best available information and shall be updated as new information becomes available or additional adaptation strategies are identified. 4.4.1 Citywide The following relate to recommended changes and updates of policies, ordinances, etc. to better help the City manage and adapt to changing vulnerability and flooding potential throughout the City. These apply to the chronic stressor of SLR and the acute stressor of a major storm event. ➢ Ensure that every CIP implemented by the City is examined through the lens of resilience. ➢ Review building and zoning codes of other Florida cities and counties for resilience and adaptation-related elements and determine if the City of Atlantic Beach’s building and zoning codes should be updated to reflect similar elements. ➢ Craft policies that do not disincentivize property owners from making repairs and renovations for resiliency purposes because such repairs may currently trigger a requirement for full compliance with all current codes. ➢ Reinforce the value of trees for absorbing stormwater runoff. ➢ Explore ways to disclose flood zone and prior flooding information on real estate transactions and lease agreements. ➢ Establish education and public engagement tools such as user-friendly websites, newsletters, social media platforms, and resource guides to reach diverse audiences. Agenda Item # 16 Jun 2025 Page 85 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-10 ➢ Establish a community relief center to enable and provide assistance to citizens to deal with stressors related to water inundation. ➢ Keep shorelines natural by implementing a 6-foot low-maintenance buffer (no mowing, fertilizer, pesticide, or herbicide application) along public lands adjacent to waterways and drainage ditches. This should also be encouraged along waterways on private property through education and outreach. ➢ Partner with COJ, Jacksonville Port Authority (JAXPORT), and the US Army Corps of Engineers (USACE) to develop a program for the beneficial reuse of dredged material through Thin Layer Placement (TLP), or other methods of strategic placement. This may be especially important to the City’s marsh system. TLP may help to build the marsh up ahead of SLR and prevent marsh areas from converting to open waters, resulting in a reduction of wave energy reaching the upland shoreline. ➢ Work with COJ to establish an outreach program to provide voluntary property vulnerability assessments in vulnerable areas of the City. Provide property owners with suggested adaptation actions they may wish to undertake to increase resiliency to SLR, storm surge, and extreme tides while simultaneously providing habitat and water-quality benefits. ➢ Map riparian areas subjected to invasive species (i.e., Brazilian Pepper), develop a program to eradicate species on public property, and provide guidance to owners of infested private properties. Invasive species often do not provide the degree of protection from erosion and wave attenuation that native species do. ➢ Ensure that the DCSPP remains funded and provides for continuous beach and dune restoration on an as-needed basis. ➢ Incorporate Environmental Protection Agency (EPA) Green Streets concepts such as green infrastructure and drainage into medians, sidewalks, and landscaped areas during the planning and design of roadway transportation projects. ➢ Seek state and federal assistance, when available, to help pay for removing remaining septic tanks on the west side of the City, and work with COJ for removing septic tanks within the Public Utilities service area that fall outside the City’s limits. ➢ Incentivize low-impact design (LID) practices. LID can include rain gardens, recessed planting beds, bio-swales, green roofs, or simply planning for a greater pervious surface in site design. ➢ Review minimum off-street parking requirements. Today, off-street parking minimums for residential and commercial developments artificially inflate the number of parking spaces; therefore, impervious surface areas must be developed. This contributes to the amount of stormwater runoff generated from developments and increases flooding potential, especially in areas that do not have space to add stormwater ponds. Agenda Item # 16 Jun 2025 Page 86 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-11 ➢ Consider revising minimum FFEs for areas in a 500-year flood zone on the current FEMA Flood Insurance Rate Map. The extents of a 500-year flood event are similar to the predicted extents of a 100-year flood event in 2044. Minimum FFEs in these areas could be revised to 2.5 feet above the nearest adjacent 100-year base flood elevation to provide for future protection. Building height limitations in these areas could also be revised to be based on the required FFE, similar to Sec. 24-81(n)(a). The current minimum FFE in an area impacted by a 100-year flood event (Special Flood Hazard Area) is 2.5 feet above the base flood elevation. These recommendations are primarily near-term recommendations (i.e., within 12 months). A specific implementation schedule should be developed to further prioritize, evaluate, refine, and consider for implementation. 4.4.2 Areas West of Mayport Road As verified by the Coastal Vulnerability Assessment, the marsh-facing areas west of Mayport Road will be particularly vulnerable to flooding events given higher sea levels in the future. Many residents in this area are already impacted by nuisance flooding that is projected to get worse. ➢ Commission a study within the next 12 to 36 months to evaluate the most cost-effective means of protecting this area of the City. This evaluation should result in the development of a 25-year plan for managing nuisance flooding and storm surge in this area to maximize protection of affected residential and commercial properties, critical facilities, and infrastructure and roadways. The plan shall include implementation triggers, expected timeframes, and probable costs for proposed improvements. Improvements that are expected to be evaluated include but are not limited to the following: o Strategically raising centerline road elevations to protect inland properties. o Installing check valves in drainage ditches to prevent storm surges from entering inland areas. o Extending water and sewer utilities where needed to ensure continuity of service. o Raising vulnerable structures to a safe elevation. o Identifying and conserving properties strategically located along the marsh edge to maintain or develop the ability to reduce wave impacts on the immediately adjacent upland areas. o Evaluate the rate and extent of marsh erosion and develop plans to stem the loss of marsh and commensurate loss of storm protection benefits. ➢ Complete a marsh baseline study within the next 12 months. Little quantitative information is available regarding the health of the marsh system within the City limits. As part of this Agenda Item # 16 Jun 2025 Page 87 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-12 effort, the City should complete a marsh baseline study to determine the current condition, extent, and elevation of the marsh so that future changes can be monitored. Periodically monitoring changes in the marsh will provide valuable information regarding the speed and extent of local impacts of SLR and will be a useful tool for future adaptation planning. A screening level review was completed to identify improvement concepts and general locations that could be considered in future studies for protecting the areas west of Mayport Road. ➢ Raise Camelia Street between 1st Street and 6th Street, 6th Street between Camelia Street and Jasmine Street, and Jasmine Street from 6th Street to approximately 350 feet north of 6th Street out of the 100-year surge floodplain. This concept may require upsizing of the stormwater collection system and includes installing backflow prevention systems on the stormwater outfalls. This improvement could provide protection for the properties and City roadways east of Camelia Street from a 100-year storm surge flood event. ➢ Raise 6th Street between Jasmine Street and Begonia Street and Begonia Street from 6th Street to approximately 450 feet north of 6th Street above the projected 2050 high-tide flood elevation. This improvement could protect Begonia Street and properties east of Begonia Street from future high-tide/nuisance flooding. ➢ Construct a backflow prevention system and stormwater pump station in the ditch in the open right-of-way on Camelia Street between 9th Street and 14th Street. This system could protect the City roadways and properties east of Camelia Street from the 100-year storm surge flood event. ➢ Raise Main Street between 9th Street and 14th Street out of the 100-year storm surge elevation and install backflow prevention on the cross-culverts in the ditch under main street. This improvement may require up-sizing the cross-culverts under Main Street to ensure that rainfall induced flooding in the area is not worsened. This improvement could protect Main Street and the City roadways and properties east of Main Street from the 100-year storm surge. ➢ Raise West Plaza Street west of Tulip Street and Gladiola Street above the high- tide/nuisance flood elevation. This improvement could reduce the amount of nuisance flooding experienced on these roadways and improve ingress/egress for residents during flood conditions. ➢ Raise West Plaza Street between Tulip Street and Begonia Street and Tulip Street from West Plaza Street to approximately 200 feet south of West Plaza Street above the high- tide/nuisance flood elevation. This improvement could reduce the amount of nuisance flooding experienced on these roadways and improve ingress/egress for residents during flood conditions. 4.4.3 Major Drainageways Of significant importance to the City of Atlantic Beach residents east of Mayport Road is the performance of the major drainageways during severe storm events. Performance of these systems is crucial regarding limiting the extent and duration of a flooding event. The City Commented [AG4]: Draft language from Jones Edmunds Agenda Item # 16 Jun 2025 Page 88 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-13 completed a Stormwater Master Plan Update in 2018 and staff have been implementing the recommendations in this plan as funding allows. The Coastal Vulnerability Assessment resulted in the prediction of future flooding associated with SLR and continued redevelopment within the City. This work was completed subsequent to the Stormwater Master Plan Update; therefore, the potential impacts from SLR are not wholly reflected in the recommended CIP resulting from the Stormwater Master Plan Update: ➢ Within the next 12 months, initiate a study to evaluate the major drainageway projects included in the current stormwater CIP regarding the increasing flooding due to SLR. This study should include development of a plan of action to account for these future conditions. This process will ensure that all major drainage infrastructure projects and improvements can be adapted to future conditions and will be complementary to potential future projects, such as stormwater pump stations, that may become necessary as sea level and flooding conditions change. ➢ Within the next 12 to 36 months, engage a consultant to develop a 50-year plan for managing the major drainageways to maximize protection of affected residential and commercial properties, critical facilities, infrastructure, and roadways. This plan should include a local, COJ, state, and federal agency coordination plan, implementation triggers, expected timeframes, and probable costs for proposed improvements. The 2018 Stormwater Master Plan Update and subsequent Coastal Vulnerability Assessment concluded that the box culvert on SR A1A at Puckett Creek is severely undersized and contributes to poor performance of the Puckett Creek and Sherman Canal watersheds. This culvert is outside the City limits and is owned by FDOT; therefore, the City of Atlantic Beach has no jurisdiction over it. However, the City has initiated discussions with FDOT regarding upsizing the box culvert to improve drainage. City staff must continue communicating with FDOT and lobbying for the culvert’s replacement. Hopkins Creek and Sherman Creek Adaptation Strategies for Future Consideration Results from the Coastal Vulnerability Assessment show that residential and commercial properties are vulnerable to widespread rainfall and storm surge driven flooding along Hopkins Creek and Sherman Creek under existing conditions. Flood conditions on these drainageways will continue to worsen with rising sea levels and more frequent extreme rainfall events. Large - scale long-term adaptation strategies will need to be implemented for these drainageways to reduce existing flood conditions and/or prevent them from worsening in the future. Hopkins Creek and Sherman Creek are both influenced by tidal and storm surge conditions. To protect these areas from flooding in the future, the City will likely need to construct backflow prevention systems with high-capacity stormwater pump stations. Detailed feasibility studies will be required to identify the exact locations for these systems, how big they will need to be, and determine how much they will cost to implement. A screening level review was completed for Agenda Item # 16 Jun 2025 Page 89 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-14 this adaptation plan to identify concepts and general locations that could be considered in future studies for protecting these critical drainageways. For Hopkins Creek, the following locations and concepts were identified: ➢ Purchase the parcel at 1401 Atlantic Boulevard, demolish the existing structures on the parcel, and construct a stormwater pond with a pump station. Flow from Hopkins Creek north of Atlantic Boulevard would be diverted into the pond. Water would exit the pond through gravity flow under lower tide conditions and be pumped out when tides are elevated. Construction of a stormwater pond with the pump station provides additional attenuation volume in the system and will reduce the required pump capacity. ➢ Construct a backflow prevention system on the Hopkins Creek box culverts at Atlantic Boulevard and construct a high-capacity stormwater pump station on the north side of Atlantic Boulevard that discharges downstream of the Atlantic Boulevard box culverts. For Sherman Creek, the following locations and concepts were identified: ➢ Construct a backflow prevention system on the Sherman Creek box culverts at Mayport Road and construct a high-capacity stormwater pump station on the east side of Mayport Road that discharges downstream of the Mayport Road box culverts. ➢ Construct a backflow prevention system in the ditch at the north end of Selva Marina Drive with a stormwater pump station that discharges into the wetland system west of Selva Marina Drive. Install backflow prevention on the existing stormwater outfall pipes that discharge into Sherman Creek at Saturiba Drive, Country Club Lane, and 11th Street. The intent of this system is to provide flood protection for the City east of Selva Marina Drive. ➢ Construct a backflow prevention system on the box culverts under the entrance of Fleet Landing at 20th Street with a stormwater pump station that discharges into the wetland north of the Fleet Landing entrance. This improvement would also require construction of a flood wall to prevent backflow through Fleet Landing in future conditions 100-year surge scenarios. As documented in the 2018 Stormwater Master Plan Update, Hopkins Creek between Atlantic Boulevard and Plaza has experienced significant and repeated rainfall driven flooding in recent years. The 2018 Stormwater Master Plan Update identified several stormwa ter system improvements that the City has been working on implementing as budgets and grant funding has allowed. This area should continue to be studied to identify additional improvements that could reduce rainfall driven flooding. A screening level review was completed for this adaptation plan to identify concepts that could be considered in future studies for reducing rainfall driven flooding in this area. ➢ Construct a new outfall pipe along Plaza, 12th Street, and Orchid Street to divert stormwater runoff from Hopkins Creek north of Plaza to the existing stormwater ditch between 14th Street and 9th Street west of Mayport Road. The existing ditch discharges Agenda Item # 16 Jun 2025 Page 90 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-15 west into the Atlantic Intracoastal Waterway and has existing culvert crossings at Hibiscus Street and Main Street that would likely need to be upsized. ➢ Construct a new outfall pipe from the ditch between Saratoga Circle North and Forrestal Circle South that discharges west into the Atlantic Intracoastal Waterway. This would divert stormwater runoff from the area west of Aquatic Drive between Plaza and Atlantic Boulevard away from Hopkins Creek. As sea levels continue to rise, tidally driven nuisance flooding will continue to worsen and become a problem in lower-lying areas along the Hopkins Creek and Sherman Creek drainageways. Where feasible, the primary method for reducing the impact of nuisance flooding is installing backflow prevention on stormwater pipes. A screening level review was completed to identify locations where backflow prevention could be installed at the downstream ends of collection system pipes to reduce nuisance flooding under existing and projected future conditions tidal flooding. The locations identified for potential backflow prevention on Hopkins Creek are: ➢ The 24-inch outfall pipe on Aquatic Drive located approximately 450 north of the centerline of Atlantic Boulevard. Aquatic Drive has roadway elevations below the existing tidal flood elevation. Therefore, tidal flooding could be reduced for existing conditions. ➢ The 29-inch-by-45-inch outfall pipe from Aquatic Drive into the Aquatic Drive pond. Aquatic Drive has roadway elevations below the existing tidal flood elevation. Therefore, tidal flooding could be reduced for existing conditions. ➢ The double 24-inch pipes under the entrance road to Lift Station F. Tidal flooding upstream of the pipes is minimal for existing conditions, but is predicted to increase significantly by 2050. ➢ The 29-inch-by-45-inch Skate Road outfall pipe between Cutlass Drive and Cavalla Road that discharges into the Skate Road ditch. Tidal flooding upstream of the pipe is minimal for existing conditions, but is predicted to increase significantly by 2050. ➢ The 34-inch-by-53-inch Cavalla Road outfall pipe that discharges into the Skate Road ditch. Tidal flooding upstream of the pipe is minimal for existing conditions, but is predicted to increase significantly by 2050. ➢ The 38-inch-by-60-inch and 42-inch outfall pipes from the stormwater pond at the Atlantic Beach Dog Park that discharge into Hopkins Creek. Tidal flooding upstream of the pipe is minimal for existing conditions, but is predicted to increase significantly b y 2050. The locations identified for potential backflow prevention on Sherman Creek are: ➢ The 48-inch outfall pipe from Pine Street that discharges into Sherman Creek at the south end of Howell Park. Tidal flooding upstream of the pipe is minimal for existing conditions, but is predicted to increase significantly by 2050. Agenda Item # 16 Jun 2025 Page 91 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-16 ➢ The 30-inch outfall pipe from the Sevilla Condominiums stormwater pond that discharges into Sherman Creek. Tidal flooding upstream of the pipe is minimal for existing conditions, but is predicted to increase significantly by 2050. ➢ The 30-inch outfall pipe at the west end of Saturiba Drive that discharges into Sherman Creek. Tidal flooding upstream of the pipe is minimal for existing conditions, but is predicted to increase significantly by 2050. ➢ The 4-foot-by-7-foot box culvert crossing under 20th Street between Brista De Mar Circle and Garden Lane. Tidal flooding occurs upstream of this culvert on Creekside Circle under existing conditions and is predicted to increase significantly by 2050. Alternatively, the City could consider installing backflow prevention measures at larger downstream culvert crossings in Hopkins Creek and Sherman Creek to reduce tidal and storm surge driven flooding in the creeks. For Hopkins Creek, installing these measures could be effective at the box-culvert crossing under Atlantic Boulevard and for Sherman Creek it could be effective at the Mayport Road box-culvert crossing. Backflow systems considered at these locations could include amil gates, floating water control weirs, and flap gates, but additional studies and analysis would be needed to determine the best options and locations . The Dora Drive and Stanley Road area was identified as flood-prone in the 2018 Stormwater Master Plan Update. Outfall pipe improvements were proposed in the Master Plan Update for this area and the City is moving forward with plans to construct the improvements. Since the Master Plan Update was completed, the City purchased vacant land at the east end of Dora Drive with the intent of constructing a stormwater pond to further reduce flooding in the area. The City is currently pursuing grant funding to design and construct the stormwater pond and should continue moving forward with design and construction as funding allows. 4.4.4 Roadways The roadways evaluated as part of this effort include major ingress and egress roads within the City limits, excluding Atlantic Boulevard and Mayport Road, which are controlled by FDOT. The ranking presented in Section 3.3 provides a roadmap in order of importance regarding each vulnerable road segment. Recommendations related to these roadway segments are as follows: ➢ Review the current pavement management plan and update it as necessary to reflect the roadway segment ranking within the next 12 months. ➢ Before repaving or making major improvements to any vulnerable roadway segments, determine improvements that can be made to increase the roadway segment’s resilience and ability to function during predicted 2044 100-year flooding conditions. ➢ Evaluate minor arterial roadways on a case-by-case basis to identify potential improvements resulting in better performance due to chronic and acute flooding conditions. ➢ Ensure that City staff share vulnerability data with FDOT to help inform their adaptation planning regarding Atlantic Boulevard and Mayport Road. Commented [AG5]: Draft language from Jones Edmunds Agenda Item # 16 Jun 2025 Page 92 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-17 The initial planning required to implement these recommendations should commence within 12 months, and these recommendations should be implemented within 24 months or before any major capital expenditures relating to improvements of any ranked roadway segment. Based on results from the Coastal Vulnerability Assessment the following roadway segments were included in the “highest” vulnerability rating category and improvements for reducing their vulnerability to flooding should be considered: ➢ Selva Marina Drive between Saturiba Drive and Country Club Lane. This section of roadway is vulnerable to flooding in the existing conditions 100 -year rainfall and storm surge flood scenarios. ➢ Sherry Drive between 8th Street and 4th Street. This section of roadway is vulnerable to flooding in the existing conditions 100-year rainfall and storm surge flood scenarios. ➢ Plaza at the Sherman Creek box culvert crossing. This section of roadway is vulnerable to flooding in the existing conditions 100-year rainfall and storm surge flood scenarios. Raising the road at this location would require improvements to the Sherman Creek box- culvert crossing. Improvements to this culvert crossing were recommended in the 2018 Stormwater Master Plan Update. ➢ Seminole Road between Seaspray Avenue and Plaza. This section of roadway is vulnerable to flooding in the existing conditions 100-year rainfall and storm surge flood scenarios. Raising the road at this location would require improvements to the Sherman Creek box-culvert crossing. Improvements to this culvert crossing were recommended in the 2018 Stormwater Master Plan Update. ➢ Selva Marina Drive from 500-feet north of 20th Street to 500-feet south of 20th Street. This section of roadway is vulnerable to flooding in the existing conditions 100-year rainfall and storm surge flood scenarios. 4.4.5 Critical Utility Infrastructure Vulnerable City-owned critical utility infrastructure within and outside the City limits include sewer pump stations, potable water plants, and several potable water wells. The Public Utilities Department shall implement the following recommendations to ensure continuity of service under all conditions: ➢ Within the next 12 months, retain a consultant to evaluate all identified exposed critical utility infrastructure with a ranking of 15 or higher to identify improvements required to protect these assets from expected 100-year event flood levels in 2044. These improvements shall be implemented within 12 months of completion of the evaluation or sooner as funding becomes available. ➢ Within the next 24 months, retain a consultant to evaluate all identified exposed critical utility infrastructure with a ranking of less than 15 to identify improvements required to protect these assets from expected 100-year event flood levels in 2044. These Commented [AG6]: Draft language from Jones Edmunds Agenda Item # 16 Jun 2025 Page 93 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-18 improvements shall be implemented within 36 months of completion of the evaluation or sooner as funding becomes available. The City has identified and begun modifying and/or raising 14 vulnerable sanitary sewer lift stations as funding has allowed. The Coastal Vulnerability Assessment identified 10 pump station with a priority rating of “highest” or “high” that the City should continue to prioritize in their adaptation efforts. The stations identified in the Coastal Vulnerability Assessment include: ➢ The Courtyards Lift Station. ➢ Lakeside Lift Station. ➢ Lift Station A. ➢ Lift Station B. ➢ Lift Station C. ➢ Lift Station G. ➢ Lift Station L. ➢ Lift Station N. ➢ Mimosa Cove Lift Station. ➢ Buc Master Lift Station. 4.4.6 Critical Public Facilities Several vulnerable critical public facilities must be addressed to ensure continuity of government and community services. The City shall implement the following recommendations: ➢ Within the next 12 months, evaluate all identified exposed critical public facilities with a ranking of 15 or higher to identify improvements required to protect these assets from expected 100-year event flood levels in 2044. These improvements shall be designed and implemented as soon as possible after completion of the evaluation. ➢ Within the next 24 months, evaluate all identified exposed critical public facilities with a ranking of less than 15 to identify improvements required to protect these assets from expected 100-year event flood levels in 2044. These improvements are to be designed and scheduled for implementation as funding becomes available. Commented [AG7]: Add map of Lift station locations Commented [AG8]: Draft language from Jones Edmunds Agenda Item # 16 Jun 2025 Page 94 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-19 Based on results from the Coastal Vulnerability Assessment sensitivity analysis, City Hall, the Commission Chamber building, and the Public Safety (fire and police) building should be prioritized for identifying adaptation needs and strategies to flood proof the facilities. The City has already implemented improvements at these facilities, but additional studies and improvements are needed. Relocation of these facilities out of the floodplain could also be considered if city- owned parcels were available that could accommodate the facilities. This option would cost considerably more than flood-proofing, but would provide the most protection for these facilities.Commented [AG9]: Draft language from Jones Edmunds Agenda Item # 16 Jun 2025 Page 95 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 4-1 Agenda Item # 16 Jun 2025 Page 96 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 5-1 Recommended Actions This Preliminary Adaptation Plan is the result of the first iteration of the City’s adaptation planning process. This Plan contains general recommendations for adaptation strategies to be applied to exposed areas of the City as well as a recommended implementation schedule. Subsequent iterations of this living document will be completed after solicitation of public input and will contain additional objective data, more specific strategies, and updated implementation schedules as appropriate. 5.1 Summary of Recommended Actions and Schedule Table 5-1 summarizes the recommendations for adaptation strategies identified in each focus area with a recommended timeframe for implementation. The timeframes for initiation are based on the following criteria: ➢ Ongoing ➔Actions currently being undertaken by staff ➢ Immediate ➔ Upon adoption of Adaptation Plan ➢ Near-Term ➔ <12 months ➢ Mid-Term ➔ 12-36 months ➢ Long-Term ➔ 36-48 months Table 5-1 – Summary of Recommendations and Implementation Schedule Recommendation Action Timeframe for Initiation Review all capital projects in context of adaptation Incorporate into project planning procedures Immediate Building and zoning code review Initiate review process and produce report of recommended actions Near-Term Policies to encourage homeowner resiliency projects Establish policies Mid-Term Reinforce value of trees for absorbing runoff Develop educational materials; coordinate with COJ efforts Near-Term Real estate disclosures Initiate discussions with Property Appraiser and develop approach for implementation Mid-Term Education and Public Engagement Tools Develop/adapt educational materials Near-Term Low maintenance buffers on City property Establish policy Immediate Marsh restoration partnering w/ COJ, JAXPORT, USACE Begin planning, discuss with relevant agencies, determine funding sources Long-Term Work with COJ on vulnerability outreach program Begin coordination and development of outreach materials Mid-Term Invasive species mapping in riparian areas Complete map and develop eradication plan Near-Term Maintain federal authorization for beach renourishment Maintain contact with USACE, COJ and FDEP to assure authorization is maintained Ongoing Commented [AG10]: Working on update to timeframes Agenda Item # 16 Jun 2025 Page 97 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 5-2 Incorporate EPA Green Streets into planning & projects Incorporate in to Complete Streets program Near-Term Seek funding to phase out septic tanks Initiate discussions with COJ, FDEP and SJRWMD to identify funding opportunities Ongoing Incentivize LID practices Develop LID guide and update code as necessary to incentivize Near-Term Review minimum off-street parking requirements Review and update applicable sections of code Near-Term Revise minimum FFEs in exposed areas Evaluate impact of change and implement code change Mid-Term Table 5-2 – Areas West of Mayport Road Recommended Actions & Schedule Recommendation Action Timeframe for Initiation 25-Year plan for SLR protection Commission evaluation and present options to the community Mid-Term Marsh baseline study Commission study Near-Term Table 5-3 – Major Drainageways Recommended Actions & Schedule Recommendation Action Timeframe for Initiation Evaluation of current CIPs Initiate review of projects Near-Term 50-year drainage plan Engage consultant to develop 50-year plan; incorporate findings in to the CIP Long-Term Table 5-4 – Roadways Recommended Actions & Schedule Recommendation Action Timeframe for Initiation Rank roads in pavement management plan Review & update pavement management plan Near-Term Improve resilience of vulnerable roadways prior to repaving or making major improvements Evaluate roadway projects as they arise Ongoing Minor arterial roadway evaluation Evaluate in response to inspections and complaints Ongoing Atlantic Boulevard and Mayport Road resiliency Coordinate w/ FDOT Ongoing Agenda Item # 16 Jun 2025 Page 98 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 5-3 Table 5-5 – Critical Utility Infrastructure Recommendation Action Timeframe for Initiation Evaluate and upgrade exposed infrastructure w/ ranking >=15 Evaluate and implement recommended improvements Near-Term Evaluate and upgrade exposed infrastructure w/ ranking <15 Evaluate and implement recommended improvements Mid-Term Table 5-6 – Critical Public Facilities Recommendation Action Timeframe for Initiation Develop plan for exposed facilities with ranking >= 15 Complete plan; design and schedule recommended improvements Near-Term Develop plan for exposed facilities with ranking <15 Complete plan; design and schedule recommended improvements Mid-Term 5.2 Monitoring and Evaluation This Adaptation Plan is a living document and the recommendations and implementation schedule contained in the Plan must be routinely visited and updated as necessary. SLR predictions are subject to change as new information and data become available. These changes must be incorporated into the exposure and sensitivity analyses to reveal any significant changes that must be accounted for. This Plan is also expected to be revised as additional data, such as marsh baseline data, are obtained. The analyses described in the Coastal Vulnerability Assessment should be revisited every 5 years at a minimum using the most recent sea levels and SLR predictions available. Subsequent to updating these analyses, this Adaptation Plan should be revised to add additional adaptation strategies as necessary and to move projects and actions listed in Section 4.3 to Section 4.4 as they are implemented or completed. Agenda Item # 16 Jun 2025 Page 99 of 102 Phase 1 Adaptation Plan City of Atlantic Beach 6-1 References 2015 Unified Sea Level Rise Projection for Southeast Florida, Southeast Florida Regional Climate Change Compact Sea Level Rise Work Group, 2015 Adaptation Action Area Workgroup Report and Recommendations, City of Jacksonville, November 2019 City of Atlantic Beach Coastal Vulnerability Assessment, Revision April 2021 City Council Special Committee on Resiliency Final Report, City of Jacksonville, April 2021 City of Jacksonville Storm Resiliency and Infrastructure Development Review Committee Final Presentation, June 25, 2019 Climate Science Special Report: Fourth National Climate Assessment, U.S. Global Change Research Program, 2017 Florida Adaptation Planning Guidebook, FDEP, June 2018 Global and Regional Sea Level Rise Scenarios for the U.S., NOAA Technical Report NOS CO- OPS 083, 2017 Global Sea Level Rise Scenarios for the United States, NOAA Technical Report OAR CPO-1 National Climate Assessment, 2012 Incorporating Sea Level Changes in Civil Works Programs, USACE Engineer Regulation (ER) 1100-2-8162, 2013 NOAA Tides & Currents – Water Levels (https://tidesandcurrents.noaa.gov/sltrends/) Agenda Item # 16 Jun 2025 Page 100 of 102 Phase 1 Adaptation Plan City of Atlantic Beach Appendix A Inundation Scenarios and Maps Inundation scenarios and maps have been moved online as interactive maps for ease of access and viewing. This information can be accessed through the following link: Resiliency and Adaptation - Current and Future Flood Mapping Agenda Item # 16 Jun 2025 Page 101 of 102 Phase 1 Adaptation Plan City of Atlantic Beach Appendix B Public Workshop Comments No public comments have been received to date. As this is a living document that will be updated often as additional information becomes available, comments received from planned public meetings will be incorporated as appropriate in to the document and will be added to this appendix. Agenda Item # 16 Jun 2025 Page 102 of 102