Town of Longboat Key, Florida Initial Assessment to Address Sea Level Rise and Recurring Flooding

TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE AND RECURRING FLOODING

Prepared for:

Town of Longboat Key, Florida

Prepared by:

Aptim Environmental & Infrastructure, Inc.

December 2018

APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE AND RECURRING FLOODING

EXECUTIVE SUMMARY

This report represents an initial assessment of the potential for sea level rise and recurring flooding to impact the Town of Longboat Key. In this assessment, a review of historical water levels was performed to identify historical trends in sea level rise and to determine the elevations of recurring storms. A review of historical data also was performed to assess if the historical records suggested that extreme water levels had occurred in the vicinity of Longboat Key.

A survey of the public was performed to assess their concerns regarding sea level rise, and recurring flooding. A public workshop was held and provided an opportunity to gather public input into this assessment.

Meetings were held with key Town staff to solicit information regarding Town facilities, storm response procedures, as well as public safety response challenges.

This initial assessment has led to the following preliminary conclusions:

1. Sea levels have been rising at a rate of +0.11 inches per year (+1.1 inches per decade; +0.90 feet per century). Relevant future scenarios suggest to expect a rise of between 6 and 17 inches by 2050. These rates have been, and will continue to be, manageable rates of increase.

2. The Town has been, and continues to be, vulnerable to storm surge associated with recurring storm events. Recurring storm events will result in flooding of low lying streets, adjacent lands, and some residences and commercial property that were constructed prior to the adoption of minimum flood elevations.

3. Return period analysis of measured elevation data are lower than National Flood Insurance Studies’ estimates, which may be due to the lack of recent land falling hurricanes and tropical storms in the Longboat Key area.

4. On a relative scale, the vulnerability of private and public infrastructure to storm surges (measured in feet) is much greater than the impacts solely due to sea level rise (which is measured in inches). Prudent planning for the effects of recurring storm events will address long term sea level rise due to the relative magnitudes of the vertical scales.

i APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 5. A survey of residents of the Town indicates that they seem to be most concerned about emergency response times, the temporary displacement of residents in the event of flooding, the impacts of flooded homes, the disruption of public utilities, and the overall impact of storms and sea level rise on property values.

6. Previous Town efforts have improved the resiliency of Town infrastructure. There is no backlog of immediate needs. Town administration and planning have adequately provided a framework to address the potential impacts of recurring storms.

This report outlines the next steps toward the development of an adaptation plan for addressing sea level rise and recurring flooding. The report also identifies grant funding opportunities that may allow the Town to receive financial assistance with the planning and implementation efforts.

ii APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE AND RECURRING FLOODING

TABLE OF CONTENTS EXECUTIVE SUMMARY...... i I. INTRODUCTION ...... 1 II. PROJECT FRAMEWORK ...... 1 III. HISTORICAL DATA AND FUTURE SCENARIOS ...... 4 A. Sea Levels ...... 4 B. Storm Surge ...... 11 C. Rainfall ...... 14 IV. PUBLIC OUTREACH...... 16 V. WORK COMPLETED BY THE TOWN ...... 18 VI. VULNERABILITIES ...... 19 VII. CONCLUSIONS...... 21 VIII. NEXT STEPS ...... 22 IX. REFERENCES ...... 24

APPENDIX A: Digital Elevation Maps APPENDIX B: Historical Data and Future Scenarios APPENDIX C: Work Completed by the Town APPENDIX D: Vulnerabilities and Preliminary Considerations APPENDIX E: Funding Opportunities

iii APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE AND RECURRING FLOODING

I. INTRODUCTION The Town of Longboat Key is subject to long-term sea level rise and recurring storm events. The Town requested that Aptim Environmental & Infrastructure, Inc. (APTIM) develop an initial assessment of high-level resiliency/sea level rise that will help guide the Town moving forward. This is the 1st phase of a multi-step comprehensive planning effort. This work effort is intended to lead the Town toward implementing a comprehensive adaptation plan to address possible impacts from sea level rise and recurring storm vulnerability. The plan is intended to fit the size and character of the Town, and be grounded in the general economic resource capabilities of the Town1. The plan will not be an all-encompassing list of future public and private projects; but rather a road map to developing long-range adaptation strategies that will maintain flood protection and provide for the resiliency of the Town.

II. PROJECT FRAMEWORK To ensure the long-term resilience of Longboat Key, the Town should develop and implement a 1. INITIAL ASSESSMENT comprehensive sea level rise adaptation plan. A 2. VULNERABILITY ASSESSMENT framework to execute a comprehensive adaptation plan is summarized in Figure 1. The plan is based 3. ADAPTATION STRATEGIES on guidance provided by the Florida Adaptation Planning Guidebook (FDEP, 2018). 4. IMPLEMENTATION PLAN

1. Initial Assessment Figure 1. Phases of a Comprehensive Sea Level Rise Adaptation Plan The initial assessment, inclusive of this report, is the preliminary action that the Town is taking to facilitate a planning process going forward to address sea level rise and associated flooding events. The purpose of the initial assessment is to establish context early in the planning process to provide working knowledge of the variables at play, as well as to identify areas and priorities to focus on later in the Town’s planning process. Included in the initial assessment is engagement of the local community and relevant stakeholders to offer the opportunity to participate in the planning process and become vested in activities that directly affect them. The information gathered in the Initial Assessment also allows the Town to better guide the adaptation planning process as it unfolds.

1 In response to Hurricane Sandy in 2012, the State of New York pledged over $0.5B to a program called RaiseNY which aims to elevate homes out of low lying areas of the New York City region. The program likely received additional federal or local funding as well. Similar actions of this scope are not considered as part of this study.

1 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

2. Vulnerability Assessment The vulnerability assessment quantifies the vulnerability of Longboat Key and its sensitivity to sea level rise and storm impacts. Vulnerability of the Town’s infrastructure, natural environment, and safety of residents is assessed for current conditions and future scenarios of sea level rise and storms. Specific critical infrastructure and assets will be inventoried and assessed. This vulnerability assessment is scheduled for a future work assignment.

3. Adaptation Strategies Adaptation strategies are the toolkit of responses for a community to address sea level rise. Actionable adaptation strategies are developed by combining engineering protection measures, policy initiatives, and land use management strategies. A range of adaptation strategies are prioritized based on established vulnerability metrics. Preferred adaptation strategies will be identified and tailored that best fit the needs and goals of Longboat Key. This assessment of strategies is scheduled for a future work assignment.

Some communities, who are also working to address sea level rise, have considered options in evaluating which adaptation strategies best fit their community. The following is provided to the Town of Longboat Key for future consideration. Some strategies may not be applicable Town- wide, but may be applicable to some sections of the Town. Some of the strategies listed below have already been implemented by the Town as part of other government actions (for example, hurricane evacuation planning, fire and police response planning, participation in the National Flood Insurance Program Community Rating System, Town Ordinances, etc.). As such, the Town has been taking proactive steps in protecting its citizens and laying the ground work for future application of existing planning efforts to address long term sea level rise and storm vulnerability.

2 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Potential Adaptation Strategies for Consideration:

Physical Strategies: Non-physical strategies:  Raised streets and walkways Governance  Raised land  Updated design standards/building codes  Raised buildings  Floodplain management  Flood walls/seawalls/bulkheads  Inter-agency partnerships  Earthen berms or dikes  Hurricane evacuation/recovery planning  Living shorelines Informational  Temporary floodwalls/sandbags  Tide station installation/Storm surge  Floodgates at channel openings prediction system  Stormwater system improvements  Rainfall measurement  Retreat  Groundwater monitoring station installation  Subsidence measurements  Model studies Operational  Traffic detours  Emergency (fire/police) response  Emergency operations (public works)

4. Implementation Plan The implementation plan will outline a process for the Town of Longboat Key to move their plan into action. This will be in the form of a Comprehensive Sea Level Rise Adaptation Plan document that may be adopted by the Town as an official planning tool. The plan will identify costs and preliminary design features of the preferred adaptation strategies. The plan will determine sequencing and funding of short- and long-term measures. There will be a continued effort to engage the public and Town commission to educate them on the study and to garner support for resilience initiatives. This planning is scheduled for a future work assignment.

3 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. III. HISTORICAL DATA AND FUTURE SCENARIOS

A. Longboat Key Topography The Town of Longboat Key is a barrier island community located between the Gulf of Mexico and Sarasota Bay. The island contains a high nearly continuous and ridge on which Gulf of Mexico Drive was constructed. The island slopes from the sand ridge to the adjacent water bodies. The island contains a near continuous dune line to the west and broader and lower back barrier areas to the east. The back barrier areas have been dredged to create a canal fronting neighborhoods in some locations. A sample of the topography has been included in Appendix A for reference.

B. Sea Levels Independent of astronomical forces, seasonal fluctuations, and local weather influences, mean (average) sea levels in the vicinity of Longboat Key have been steadily rising. This section presents an analysis of long-term and recent trends of measured sea levels near Longboat Key, as well as future scenarios. Details of the analyses is provided in Appendix B.

1. Measured Water Levels

There is a lack of continuous, reliable water level measurements in the immediate vicinity of Longboat Key and Sarasota Bay. The closest, most reliable water level gauges in the vicinity of Longboat Key are presented in Figure 2, each operated and maintained by NOAA/NOS/CO-OPS, and published on NOAA’s Tides & Currents website (http:\\tidesandcurrents.noaa.gov). While the Port Manatee gage is the closest to Longboat Key, the duration of the measurements there is short and NOAA has not published sea level rise trends for the Port Manatee tide gage.

4 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

Figure 2. NOAA Tide Station Locations in the Vicinity of Longboat Key, Florida.

5 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Tides are hydrodynamic waves that are affected by bathymetric features; therefore, it is important to differentiate open coast measurements (Clearwater Beach) and interior bay measurements (St. Petersburg). The Clearwater Beach gage represents the closest measurement point for an open coast gage that may represent sea level changes along the Gulf facing the shoreline of Longboat Key. The St. Petersburg data represents the closest long-term record of an interior tide gage and will be utilized to represent sea level changes experienced on the back bay side of Longboat Key (Sarasota Bay). Due to the proximity of relatively deep hydraulic channels between the sites, the correlation of the water levels in the immediate back bay area of Longboat Key to those measured at the St. Petersburg gage are assumed to be high, especially regarding long-term trends of sea level rise.

The mean sea level (MSL) trend of the St. Petersburg gage, which has been collecting data relatively continuously since 1947 (71 years), is shown in Figure 3. The data represents the monthly mean sea level without the regular seasonal fluctuations due to coastal ocean temperatures, salinities, winds, atmospheric pressures, and ocean currents. The data is plotted in reference to the local MSL datum established by CO-OPS for the St. Petersburg gage for the most recent tidal epoch of 1983-2001, inclusive. Comparative gage data and other sea level rise measurements are provided in Appendix B.

St. Petersburg (8726520)

Linear Trend = +0.11 in./yr. (1947-2018)

7.7 in.

71 years

Figure 3. Long term mean sea level trend at St Petersburg Florida.

Figure 3 indicates that the historic average (linear) trend in the sea level rise data is approximately +0.11 inches/yr. This is equivalent to 7.7 inches over the 71 year measured time frame. Since approximately 2010, the rate of sea level rise has increased above the long term trend (Figure 3). Previous time frames have also shown short term increased rates of sea level rise (for example 1977-1987).

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2. Future Sea Level Scenarios Both the rate and magnitude of sea level rise (SLR) are important for vulnerability and impact assessment because the time horizon is a critical factor affecting risk tolerance for coastal management actions. Although it is clear that sea levels have risen historically (Figure 3), it is difficult to predict with certainty the extent to which sea levels will continue to rise over the coming century. This uncertainty is due primarily to the uncertainty in future greenhouse gas emissions, as well as the uncertainty in the physical response of the planet to increased concentration of greenhouse gasses in the atmosphere. For the purposes of this study, three reputable sources (NOAA, USACE, and the Intergovernmental Panel on Climate change (IPCC)) were investigated to determine future SLR scenarios in the vicinity of Longboat Key. Each of the sources are shown in Figure 4. Figures 5, 6, and 7 display the scenarios through 2100 developed by these sources that have been regionally applied to the St. Petersburg gage. Curve development details are provided in Appendix B.

NOAA USACE IPCC

(2017) (2014) (2013)

Figure 4. Sources of Sea Level Rise Scenario Development.

The future sea level curves are scenarios based on certain assumptions. As such, they are not forecasts or predictions of future sea level, but rather estimates of what might occur under certain circumstances.

7 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. a. NOAA

NOAA

St. Petersburg (8726520)

Figure 5. NOAA Developed Scenarios of Sea Level Rise for St. Petersburg Gage.

b. USACE

USACE

St. Petersburg (8726520)

Figure 6. USACE Developed Scenarios of Sea Level Rise for St. Petersburg Gage.

8 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. c. IPCC

IPCC

St. Petersburg (8726520)

Figure 7. IPCC Developed Scenarios of Sea Level Rise for St. Petersburg Gage.

d. Scenario Comparison Figure 8 displays all of the previously described SLR scenarios for the 1990 to 2050 timeframe. It is difficult to identify one or more scenario curves (Figure 8) that best match the measured St. Petersburg data, due to the short comparative period (1992-2018) and due to the high frequency sea level changes that are superimposed on the long term SLR signal. Nevertheless, the trend of the St. Petersburg data appears to disagree with the lowest and highest scenarios; Linear Trend and NOAA High, respectively.

With the Linear Trend and NOAA High curves not considered, the lower and upper boundary curves are the USACE Low (equivalent to the NOAA Int. Low) and the USACE High, respectively. As such, it is recommended that the Town consider utilizing the USACE Low and USACE High curves to establish a reasonable SLR range as a baseline planning tool. It is also recommended that the measured data be reassessed every 3-to-5 years to verify if the measured data is trending as anticipated, or if different scenarios need to be considered. This will allow the Town to refine the SLR range accordingly over time. Due to the wide variation in scenario curves out to 2100, it is also recommended the Town focus on an initial planning horizon of no more than approximately 30 years (to 2050).

9 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. St. Petersburg (8726520)

Figure 8. Sea Level Rise Scenarios for St. Petersburg Gage (1990-2050).

Figure 9 displays the USACE SLR scenarios out to the year 2050. The curves indicate that the MSL may rise 2 to 6 inches by 2030, 4 to 11 inches by 2040, and 6 to 17 inches by 2050. The projected increased SLR rates are still manageable for planning and adapting during this timeframe. Supplemental discussions are provided in Appendix B.

6” to 17” rise by 2050 4” to 11” rise by 2040 2” to 6” rise by 2030 St. Petersburg (8726520)

Figure 9. USACE Sea Level Rise Scenarios for St. Petersburg Gage (1990-2050).

10 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. C. Storm Surge Storm surges are short duration elevated waters usually associated with individual storm events and are frequently associated with the winds and low atmospheric pressures of tropical storms. In this analysis, storm surge is included within the total water levels and includes the effects of winds, atmospheric pressure, or oceanographic water movement. This section presents a summary of an analysis of measured peak water levels due to storms in the vicinity of Longboat Key. Details are provided in Appendix B.

Future SLR will magnify the coastal flood risks as the frequency and magnitude of coastal flooding will increase as SLR increases the base water level upon which storm surge and waves act. This analysis also assumes that any future climatic changes do not implicitly increase current flood risks due to storm surge.

1. Measured Water Levels Just as in the case of the sea level rise analysis, there is a lack of continuous water level measurements in the immediate vicinity of Longboat Key and Sarasota Bay. Therefore, data from NOAA’s St. Petersburg gage (Station ID 8726520) is utilized to analyze peak water levels. Verified hourly water level data exists back to 1947 with few interruptions in the data set (most notably in late-1947, late-1952, and nearly all of 1964). Figure 10 displays the water level elevations relative to NAVD.

St. Petersburg (8726520) NO DATA

Figure 10. Water Level Measurements at St. Petersburg Gage.

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2. Water Level Return Period Analysis A return period analysis of the extreme water elevation events was undertaken for the St. Petersburg measured water elevations and is presented in Appendix B. To determine the frequency of occurrence of the extreme water levels, a return period analysis was conducted on the extreme events to determine the distribution of the extreme events. The results are presented in Figure 11. The return period elevations were compared and contrasted to other return period analysis elevations that were developed for the area with mixed results (Appendix B). The return period elevations of several numerical model studies agree fairly well for the higher frequency events (more frequent than a 10-yr event); however, the return period elevations for the lower frequency events are significantly higher than those calculated from the St. Petersburg gauge.

The 10 highest peak water levels shown in Figure 11 were investigated for their relationship to known storms (Appendix B). As expected, most of the top events are associated with the passage of tropical storms and hurricanes.

Return Pd. Water Elev. Water Elev. (years) (ft, MSL*) (ft, NAVD) 1 2.4 2.5 2 2.9 2.9 5 3.4 3.5 10 3.8 3.9 20 4.2 4.3 30 4.5 4.5 40 4.7 4.7 50 4.8 4.9

MSL* indicates that the elevations are relative to a concurrent MSL datum.

Best Fit Exponential F’n (f’n relative to concurrent MSL) y = 0.6034 Ln(x) + 2.437 St. Petersburg (8726520) R² = 0.9874

Figure 11. Return Period Analysis from the St. Petersburg Gage.

12 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 3. Historical Extreme Events

While the data analysis confirms that tropical storms and hurricanes create significant surge events that impact Longboat Key, the elevations for return periods greater than 10 years were perceived to be lower than similar estimates from the FEMA Flood Insurance Studies (see Appendix B, Table B.2). One of the reasons for these lower values is that the Longboat Key area has not experienced the direct impact of a major land falling hurricane in a relatively long time.

To evaluate the potential effect of hurricanes on Longboat Key, a preliminary review of newspaper articles and anecdotal accounts was performed (Ref. www.longboatkeyhistory.com and www.sarasotahistoryalive.com). This anecdotal data indicates that extreme water levels impacted Longboat Key and that they occurred prior to most of the development. Three events of note that took place prior to the establishment of the St. Petersburg water level gauge are listed below:

Date Observation  1848: Hurricane made landfall in Tampa area. Surge cuts New Pass. “All of the keys were inundated.” Egmont Key Lighthouse knocked down.  1907: Tropical storm generated storm surge. “The water was just going right across the key.”- S.J. Griggs.  1921: Hurricane made landfall in Tampa. John Savarese house destroyed. St. Armands, Longboat Key and Anna Maria Island flooded.

4. Conclusions

Under present conditions, the largest vulnerability to Longboat Key is the potential for recurring storm events (mostly tropical storms and hurricanes), which can generate significant storm surge along the coast and into Sarasota Bay. While rare, the events do occur and will occur in the future (probabilistically). The combination of sea level rise plus storm surge will result in slightly higher water levels in the future. These extreme events can cause flooding of the low lying areas of Longboat Key through overtopping of low bulkheads, and backflows through unprotected stormwater pipes. Once the flooding begins, there are increased challenges to providing emergency (police, fire) services, and the potential for flooding of non-flood code compliant structures will increase.

13 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. D. Rainfall This section presents a brief analysis of rainfall totals in the vicinity of Longboat Key. Rainfall analysis is included in this study to gain perspective of the magnitude and frequency of extreme rainfall events, and to investigate if these events are becoming more intense or more frequent.

1. Measured The closest reliable long-term rain gage with easily-accessible daily rainfall data is located in Bradenton, FL (ID: USC00080945). The gage is operated by NOAA and has been consistently collecting daily rainfall totals since 1965 with very few interruptions. Figure 12 displays the daily rainfall totals for the Bradenton gage.

Bradenton (USC00080945)

Figure 12. Daily Rainfall Totals for Bradenton, FL.

2. Threshold Analysis To identify “extreme events” in each data set, a peak-over-threshold analysis was performed (Appendix B). In an effort to include events that occur once per year or less (on average), a threshold value of +3 inches (in a day) were utilized for Bradenton. Figure 13 shows the data with the extreme events identified with cyan dots, and the top 10 events identified with red dots. The Bradenton data has a relatively consistent frequency of extreme events; however, the magnitude of the events appears to be significantly more intense since about 1988. This increase in magnitude may be due to a reported change in gage equipment that was documented in March 1988. With the understanding that the Bradenton equipment was changed in 1988, there does not appear to be

14 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. a clear trend in the magnitude or frequency of extreme rainfall events. Supplemental discussions are provided in Appendix B.

Bradenton (USC00080945) 74 days in 53.3 yrs Threshold = 3 inches

Top 10 Days

Figure 13. Peak Daily Rainfall Totals for Bradenton, FL.

15 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. IV. PUBLIC OUTREACH A public information meeting to discuss sea level rise and associated recurring flooding in Longboat Key was held at the Town Hall on August 27, 2018 (Figure 14). APTIM provided preliminary findings of past and future sea level rise trends, and discussed the historical storm surges that have affected Longboat Key and the Sarasota region. Approximately 40 people were in attendance.

Figure 14. APTIM staff members during public information meeting on August 27, 2018. (mysuncoast.com)

A survey of public opinion was also circulated that requested input from residents on a range of topics. A small number of surveys were returned. The results are summarized in Table 1 on the following page. The survey also allowed residents to provide written comments, which are paraphrased below: 1. Solutions should take into account the uncertainty of the predictions of future sea level rise and recurring flooding. 2. Solutions should be incremental with capability to address near term problems while being flexible to address future (long term) changes in sea level rise. 3. While working with other governments is important, the Town needs its own plan. 4. Considering that the other economic consequences are more important, reduced tourism must be ranked lower.

Due to the small sample size, the results are likely not statistically significant. While all of the responses provide some insight into the level of importance of a particular consequence, the survey reinforces that the respondents felt that the most important consequences were those that affected the essential services of the community (emergency response, displacement of residents due to storms, disruption of public utilities) and those that directly affected individuals economically (damage to homes and businesses, and decreasing property valuations). The respondents felt that the least important consequences were loss of access to parks and recreation areas, disruption of public transportation, and reduced tourism. These public perceptions should be incorporated into future decision making.

16 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Table 1. Results of Public Survey Level of Importance (% of respondents )

Potential Consequences of long term sea level rise and associated recurring flooding events

High Medium Low Not Response No

Social Consequences: Delayed response time of emergency vehicles 100 0 0 0 0 Temporary displacement of residents 86 14 0 0 0 Loss of access to parks and recreation areas 0 28 72 0 0 Loss of local businesses on the island 57 29 14 0 0 Flooding of residential streets (other than Gulf of Mexico Drive) 72 28 0 0 0 Disruption of public transportation (i.e. trolley service, etc.) 0 28 72 0 0 Disruption of public utilities (i.e. electrical, sewer, water) 86 14 0 0 0 Environmental Consequences: Delays in residential trash pickup 43 28 29 0 0 Floating trash on the beaches and bay shorelines 57 43 0 0 0 Disruption in service of sewer system and safe drinking water 100 0 0 0 0 Loss of low-lying coastal land & associated environmental habitat 43 14 43 0 0 Economic Consequences: Damage to flooded homes and businesses 100 0 0 0 0 Damage to public infrastructure (i.e. utilities, public buildings) 86 14 0 0 0 Reduced tourism 0 43 57 0 0 Increased insurance premiums 57 43 0 0 0 Decreased property values 100 0 0 0 0 Increased demands on Town resources and staff 28 72 0 0 0 Actions should focus on: Upfront costs 43 57 0 0 0 Ongoing maintenance costs 43 57 0 0 0 Short-term return on investment (< 30 years) 43 14 29 0 14 Long-term return on investment (> 30 years) 43 43 14 0 0 Equitable distribution of benefits and costs to all residents 57 29 14 0 0 Strategies that are adaptable to address a range of SLR scenarios 86 14 0 0 0 Strategies that address multiple benefits 43 43 0 0 14 Collaborating with multiple governments 0 86 0 0 14 Establishing public and private collaborations 57 43 0 0 0

17 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. V. WORK COMPLETED BY THE TOWN The Town has planned and implemented actions over the years to address many components of a plan to improve the resiliency of the Town’s critical infrastructure. In this discussion, critical infrastructure are those components of the Town that are essential for operation and its ability to provide key or essential services to the residents. These completed actions are listed below and briefly summarized. A more detailed description of these actions can be found in Appendix C.

Critical Facilities. Over the last few decades, the Town has replaced critical facilities and infrastructure with structures that meet current (at the time) flood and building code requirements. There is no backlog of Town buildings that requires immediate replacement or upgrades.

National Flood Insurance Program (NFIP) and Community Rating System (CRS). The Town participates in the NFIP CRS, which documents building and flood code compliance for new and substantially improved existing structures. Homeowners with compliant structures incidentally receive discounts on federal flood insurance premiums.

Building Codes and Local Ordinances. As part of the Town of Longboat Key Municipal Code, the Town has adopted Ordinances to establish minimum standards and requirements for land management, building standards, and redevelopment to ensure public safety and minimize flood damage to public and private property.

Hurricane Plan. The Town has a Hurricane Plan, which describes a comprehensive program that sets guidelines to mitigate against, prepare for, respond to, and recover from, the effects of a tropical storm event impacting the Town.

Beach Management Plan. The Town has a Beach Management Plan that identifies a design width and an elevation of the minimum beach that the Town should maintain to prevent wave and storm surge induced erosion from impacting private development and public infrastructure during a moderate return period event.

In summary, the Town has been addressing its infrastructure needs as existing infrastructure reaches its useful life. Similarly, the Town has functional codes and administrative procedures to provide key and essential services to its residents.

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VI. VULNERABILITIES During the course of this initial assessment, vulnerabilities and concerns were identified that may occur as a result of sea level rise and/or recurring storm events. This list is preliminary and additional items may be identified by the Town in future phases of the adaptation planning effort. The concerns are listed in no order of severity or urgency. A more detailed description of these vulnerabilities and possible actions are found in Appendix D.

1. There is a lack of local water level measurements in the vicinity of Longboat Key and Sarasota Bay to track local long-term water levels, on which to base future decision making.

2. Low-lying streets susceptible to flooding during low return period events may impede access for emergency vehicles during heavy rains and/or high water events.

3. Nuisance flooding of select roads and adjacent lands caused by backflow of water into existing stormwater pipes during routine high astronomical tides and/or small-scale storm surges.

4. There are many low, porous, or non-existent bulkheads along the shoreline within the northern portions of the Town.

5. There are a significant number of Repetitive Loss Properties, and like-structures within the Town that are vulnerable to flooding during recurring storm events. Similarly, there are a large number of residences that were constructed prior to adoption of flood codes.

6. There may be insufficient incentive to raise the elevation of non-flood compliant structures, or to initiate redevelopment of the property to meet current flood standards.

7. The evacuation routes on the adjacent low-lying islands also are susceptible to sea level rise and recurring flooding.

8. There could possibly be negative economic effects on the real estate market due to sea level rise and recurrent flooding.

9. There is uncertainty on how to appropriately and adequately comply with real estate disclosure laws for properties vulnerable to sea level rise and recurring flooding from future storm events.

10. Over the long term (decades), the Village and other low-lying neighborhoods in northern Longboat Key may require additional or more comprehensive engineering and planning to sufficiently prevent frequent or extreme flooding of streets and/or private property and structures.

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11. Over the long term (decades), sea level rise and recurring storm events may affect the Town’s undeveloped islands within Sarasota Bay and open space parks.

12. There is uncertainty of the most appropriate redevelopment plan for low lying residential communities if they experience widespread impacts from a severe flooding or storm event.

13. There is a reliance of off-island infrastructure and services to supply potable (drinking) water to Longboat Key; therefore, resiliency and susceptibility to sea level rise and storm events of this infrastructure also affects the Town.

14. Significant increases in flood insurance premiums may affect residents and the real estate market within Longboat Key.

These vulnerabilities were identified at a qualitative level. Further evaluation of data may be prudent to quantify the impact, develop solutions to meet the Town’s goals, and prioritize actions. Further evaluation of data may also yield additional vulnerabilities not currently identified.

20 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. VII. CONCLUSIONS

This initial assessment of vulnerability to sea level rise and recurring storm events has led to the following preliminary conclusions:

7. Sea levels have been rising at a rate of +0.11 inches per year (+1.1 inches per decade; +0.90 feet per century). Relevant future scenarios suggest to expect a rise of between 6 and 17 inches by 2050. These rates have been, and will continue to be, manageable rates of increase. The Town should consider utilizing the USACE Low and USACE High curves to establish a reasonable SLR range as a baseline planning tool.

8. The Town has been, and continues to be, vulnerable to storm surge associated with recurring storm events. Analysis of peak water elevations at the St. Petersburg gage indicate the 5-yr, 20-yr, and 50-yr return period water elevations are +3.5 ft, +4.3 ft, and +4.9 ft NAVD, respectively. These elevations will result in flooding of low lying streets, adjacent lands, and some residences and commercial property that were constructed prior to the adoption of minimum flood elevations. As future sea levels rise, the recurring storm elevations will increase accordingly. The combination of future sea level rise with storm surge will create the perception that severe storms are occurring more frequently.

9. Return period analysis of measured elevation data from the St. Petersburg gage suggests that the elevation of expected recurring storms is low relative to historic modeling analyses. This is due to a lack of recent land falling hurricanes and tropical storms in the Longboat Key area. Anecdotal accounts of historic storms, that occurred prior to the majority of the development of Longboat Key, suggests that significant (approaching a 100 year event) water levels have occurred in Longboat Key.

10. On a relative scale, the vulnerability of private and public infrastructure to storm surges (measured in feet) is much greater than the impacts solely due to sea level rise (which is measured in inches). Prudent planning for the effects of recurring storm events will address long term sea level rise due to the relative magnitudes of the vertical scales.

11. Residents of the Town seem to be most concerned about emergency response times, the temporary displacement of residents in the event of flooding, the impacts of flooded homes, the disruption of public utilities, and the overall impact of storms and sea level rise on property values.

12. Previous Town efforts have improved the resiliency of Town infrastructure. There is no backlog of immediate needs. Town administration and planning have adequately provided a framework to address the potential impacts of recurring storms.

21 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

13. In undertaking this initial assessment of the potential effects of sea level rise and recurring storm events on public and private infrastructure, a list of potential areas for concern were identified. These concerns are broad and address engineering, economic, and social needs. These areas of concern should be refined and defined in future phases of the adaptation planning effort. This may require additional data collection, strategic planning, government planning, ordinance review and amendment, and supplemental engineering studies and investigations.

VIII. NEXT STEPS It is recommended that the Town consider the following next steps:

1. Specific Remedies to Address Vulnerabilities

During the course of this initial assessment, several potential concerns were identified. For each concern, a potential action items for the Town was suggested. Most of these action items require additional information prior to implementation. Some of these action items, however, can begin to be addressed without further analysis. A detailed discussion of the specific vulnerabilities and potential considerations and remedies for the Town is found in Appendix D.

2. Funding Opportunities

While the Town may fund future work efforts from its budget, it is recommended that the Town consider applying for funding (grants) related to resiliency and sea level rise adaptation. The most applicable funding opportunities that may fit the Town’s needs are provided in Appendix E.

3. Further Data Collection

Collection of the following data sets may assist the Town in further quantification of the potential threats of sea level rise and recurring storm tides. The following are provided in no order of importance, or cost:

a. Complete a stormwater atlas identifying the discharge outlet invert elevations and the stormwater road inlet elevations. Include documentation of any existing backflow protection and location on each discharge. b. Obtain a current LIDAR data set of the entire Town, including the Sarasota Bay islands. c. Perform a dune condition survey and analysis. Identify areas within the Town susceptible to storm surge and wave overtopping. Utilize existing LIDAR data sets to reduce the field topographic survey work effort. Develop a dune restoration plan for those areas with

22 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. inadequate dunes. d. Collect bulkhead elevation and condition data (at an individual property-level scale) in those sections of Town most susceptible to flooding. e. Identify and summarize critical infrastructure, including GPS locations and finished floor elevations, to be included on a GIS layer. This includes infrastructure off island that affects the Town, the status of that infrastructure, and any proposed actions. f. Identify all Town-owned parcels fronting the Gulf of Mexico, Sarasota Bay, and any of the bay fronting canals. Determine if the parcels, or adjacent parcels/infrastructure, are at current risk to storm surges, or future risk to sea level rise and storm surges.

4. Comprehensive Plan

To ensure the long-term resilience of Longboat Key, the Town should continue the process of developing and implementing a comprehensive sea level rise adaptation plan. The next step in doing so is to conduct a Vulnerability Assessment, as described in Section II.2.

5. Public Outreach

Continue public outreach and engagement through future phases of planning. This allows the local community and relevant stakeholders the opportunity to participle in the planning process and become vested in activities that directly affect them.

23 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. IX. REFERENCES Church, J. A., & White, N. J., 2011. Sea-Level Rise from the Late 19th to the Early 21st Century. Surveys in Geophysics, 32(4-5), 585–602. http://doi.org/10.1007/s10712-011-9119-1

(IPCC) Intergovernmental Panel on Climate Change, 2013. Climate Change 2013: The Physical Science Basis, Contribution of Working Group 1 to the fifth assessment report (AR5) of the IPCC. Chapter 13, Sea Level Change.

Kopp, R. E., R.M. Horton, C.M. Little, J.X. Mitrovica, M. Oppenheimer, D.J. Rasmussen, B. Strauss, C. Tebaldi. (2014). Probabilistic 21st and 22nd century sea‐level projections at a global network of tide‐gauge sites. Earth's Future, 2(8), 383-406.

(NOAA) National Oceanic and Atmospheric Administration, 2018. Tides & Currents, Sea Level Trends. http://tidesandcurrents.noaa.gov/sltrends/sltrends.html

(NOAA) National Oceanic and Atmospheric Administration, 2018. Tides & Currents. http://tidesandcurrents.noaa.gov/

(NOAA) National Oceanic and Atmospheric Administration, 2018. National Center for Environmental Information. Bradenton, FL US, GHCND:USC00080945. https://www.ncdc.noaa.gov/cdo-web/datasets/GHCND/stations/GHCND:USC00080945/detail

(NOAA) National Oceanic and Atmospheric Administration, 2012. Global Sea Level Rise Scenarios for the United States National Climate Assessment. NOAA Tech Report OAR CPO-1, dated December 6, 2012.

(NOAA) National Oceanic and Atmospheric Administration, 2017. Global and Regional Sea Level Rise Scenarios for the United States. NOAA Tech Report NOS CO-OPS 083, dated January 2017.

(SWFWMD) Southwest Florida Water Management District, 2018. Rainfall Summary Data by Region. https://www.swfwmd.state.fl.us/resources/data-maps/rainfall-summary-data-region

(USACE) United States Army Corps of Engineers, 2014. Procedures to Evaluate Sea Level Change: Impacts, Responses, and Adaptation. ETL 1100-2-1, dated June 30, 2014, expiration date March 30, 2019. van Vuuren, D. P., J. Edmonds, M. Kainuma, K. Riahi, A. Thomson, K. Hibbard…S. Rose. (2011). The representative concentration pathways: An overview, Climate Change, 109, 5–31, doi:10.1007/s10584-011-0148-z. www.longboatkeyhistory.com www.sarasotahistoryalive.com

24 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE AND RECURRING FLOODING

APPENDIX A: Digital Elevation Maps

To provide a greater understanding of the local variations in the topography of Longboat Key and to better understand that recurring flood events and sea level rise may affect specific sections of Longboat Key differently than other (higher) sections, an elevation map was created (attached). The maps indicate that the lowest lying areas of Longboat Key are northern Sarasota Bay fronting neighborhoods. In the easternmost parts of Longboat Key, there are gaps in the LIDAR data set. As a result, there are gaps in the elevation model (for example sheets 16, 19, portions of sheets 20, 22, and 28).

A-1 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Sheet 8 Sheet 10 Sheet 16 Sheet 19 Sheet 2 Sheet 4 Sheet 6 Sheet 12 Sheet 7 Sheet 9 Sheet 11 Sheet 14 Sheet 18 Sheet 20 Sheet 1 Sheet 3 Sheet 5 Sheet 28 Sheet 22 Sheet 24 Sheet 26 Sheet 13

Sheet 15 Sheet 17 Sheet 21 Sheet 29 Sheet 23 Sheet 25 Sheet 27

TITLE: Notes: Longboat Key, Florida 1. Background imagery is from Sarasota County, dated February 10, 2017. Digital Elevation Model £ Map Key APTIM Feet 2481 N. W. Boca Raton Boulevard 04,0002,000 Boca Raton, FL 33431 Ph. (561) 391-8102 Fax (561) 391-9116 1 inch = 4,000 feet Date: 09/04/18 By: HMV Comm No. : 631237290 Key G:\Enterprise\Sarasota\LBK Field 2018\BoardWork MapKey.mxd Sheet1 T WALK CB26/6 BEACH S CONDO L L E

A Y W S

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A M Sheet2

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Date: 09/04/18

TITLE:

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Notes: G:\Enterprise\Sarasota\LBK Field Work 2018\Board Map 1.mxd Map 2018\Board Work Field G:\Enterprise\Sarasota\LBK Sheet8

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Boca Raton, 33431 FL

Comm No. : 631237290 : No. Comm

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Date: 09/04/18 TITLE:

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X APARTMENTS Comm No. : 631237290 : No. Comm

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Date: 09/04/18 TITLE:

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Notes: G:\Enterprise\Sarasota\LBK Field Work 2018\Board Map 1.mxd Map 2018\Board Work Field G:\Enterprise\Sarasota\LBK Sheet12

M APTIM

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Date: 09/04/18 TITLE: £ Feet 125 1 inch = 250 feet 250 = inch 1 0250 4-5 5-6 6-7 7-8 >9 <1 2 1- 2-3 3-4 Legend: Model Elevation Digital NAVD88 Feet,

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Comm No. : 631237290 : No. Comm F

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G By:HMV

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Digital Elevation Model Elevation Digital

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Date: 09/04/18 TITLE: £ Feet 125 1 inch = 250 feet 250 = inch 1 0250 CB26/1 COURT CONDO EMBASSY I & SEA CLU KEY CLUB YAC HT CB7/96 CB4/50 TENNIS LONGBOAT CONTINENTALS II & KEY YAC HT CB5/56 TENNIS LONGBOAT 4-5 5-6 6-7 7-8 >9 CB 31/36 & TURTLE CRAWL,A CLUB CB3/73 BEACH PELICAN CONDOMINIUM HARBOUR <1 2 1- 2-3 3-4 Legend: Model Elevation Digital NAVD88 Feet,

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A Notes:

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Sheet14

U D

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A O B S U O AY B APTIM Ph. (561) 391-8102 Fax (561) 391-9116

Boca Raton, 33431 FL

Comm No. : 631237290 : No. Comm

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Legend: Model Elevation Digital NAVD88 Feet,

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A Notes:

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F T S E W APTIM Ph. (561) 391-8102 Fax (561) 391-9116

R Boca Raton, 33431 FL Comm No. : 631237290 : No. Comm

I Boca2481 N. W. Raton Boulevard

F By:HMV

Florida Key, Longboat Digital Elevation Model Elevation Digital F

Date: 09/04/18 TITLE: £ Feet 125 1 inch = 250 feet 250 = inch 1 0250

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Sheet16 N

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BO Florida Key, Longboat N

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L A

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Date: 09/04/18

TITLE:

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Fax (561) 391-9116

A S Boca Raton, 33431 FL Comm No. : 631237290 : No. Comm 2481 N. W. Boca2481 N. W. Raton Boulevard By:HMV Longboat Key, Florida Key, Longboat Digital Elevation Model Elevation Digital

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S G:\Enterprise\Sarasota\LBK Field Work 2018\Board Map 1.mxd Map 2018\Board Work Field G:\Enterprise\Sarasota\LBK TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE

APPENDIX B: Historical Data and Future Scenarios

This appendix provides an analysis and discussion of historical and projected trends for the key flood related data affecting Longboat Key: sea level rise, storm surge, and rainfall. Historical conditions provide a baseline for understanding past trends and observed impacts, while projected scenarios are provided to inform efforts to prepare for climate change and exacerbated impacts in the coming decades.

A. Sea Levels Independent of astronomical forces, seasonal fluctuations, or local weather influences, mean (average) sea levels in the vicinity of Longboat Key have been steadily rising. This section presents an analysis of long-term and recent trends of measured sea levels near Longboat Key, as well as future scenarios.

1. Local Measured Sea Levels There is a lack of continuous, reliable water level measurements in the immediate vicinity of Longboat Key and Sarasota Bay. The closest, most reliable water level gauges in the vicinity of Longboat Key are illustrated in Figure B.1, each operated and maintained by NOAA/NOS/CO- OPS, and published on NOAA’s Tides & Currents website (http://tidesandcurrents.noaa.gov). While the Port Manatee gage is the closest to Longboat Key, the duration of the water elevation measurements there is short and NOAA has not published sea level rise trends for the Port Manatee tide gage.

B-1 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

Figure B.1. NOAA Tide Stations in the Vicinity of Longboat Key

Tides are hydrodynamic waves that are affected by bathymetric features; therefore, it is important to differentiate open coast measurements (Clearwater Beach) and interior bay measurements (St. Petersburg). The Clearwater Beach gage represents the closest measurement point for an open coast gage that may represent sea level changes along the Gulf facing shoreline of Longboat Key. The St. Petersburg data represents the closest long-term record of an interior tide gage and will be utilized to represent sea level changes experienced on the back bay side of Longboat Key (Sarasota Bay). Due to the proximity of relatively deep hydraulic channels between the sites, the correlation of the water levels in the immediate back bay area of Longboat Key to those measured at the St. Petersburg gage are assumed to be high, especially regarding long-term trends of sea level rise.

Figure B.2 shows the mean sea level (MSL) of the St. Petersburg gage, which has been collecting data relatively continuously since 1947 (71 years). The data represent the monthly mean sea level without the regular seasonal fluctuations due to coastal ocean temperatures, salinities, winds, atmospheric pressures, and ocean currents. The data is plotted in reference to the local MSL datum established by CO-OPS for the St. Petersburg gage for the most recent tidal epoch of 1983-2001, inclusive. As such, the MSL elevation is zero at the mid-point of the referenced epoch (mid-1992). For reference, the St. Petersburg MSL datum established for this epoch is located 0.28 ft below the North American Vertical Datum of 1988 (NAVD88 or simply NAVD).

B-2 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. St. Petersburg (8726520)

Linear Trend = +0.11 in./yr. (1947-2018)

7.7 in.

71 years

Figure B.2. Sea Level Rise Trend at St. Petersburg Gage.

An average sea level rise of +7.7 inches is observed from 1947 to 2018, equating to an average of +0.11 inches per year. For reference, the average global sea level rise over a similar time period (1940-2010) is +0.09 inches per year (Church and White, 2011). Recent measurements reveal a slight positive deviation from the linear trend, beginning around 2010. This may be interpreted as a routine short-term positive deviation that regularly occurs throughout the record with similar magnitude and duration (such as between 1967-1975 and 1977-1987); or this may be interpreted as the first indication of a long-term accelerated trend. Analysis of future measurements is necessary to interpret if the recent acceleration is a short-term deviation or the beginning of long- term acceleration.

2. Regional Measured Sea Levels

Data encompassing the larger regional area was compared to the St. Petersburg data to determine if the St. Petersburg measurements and trends are in line with the regional data, or if they are outliers. Figure B.3 displays the St. Petersburg data (blue line) along with the average of eight NOAA gages located in the eastern Gulf of Mexico (Dauphin Island, Pensacola, Apalachicola, Cedar Key, St. Petersburg, Fort Myers, Naples, and Key West)2 (orange line), and data from satellite radar altimetry measurements averaged for the entire Gulf of Mexico (seasonal signals removed)3 (green line). The magnitude and trend of the local St. Petersburg data are in close

2 https://tidesandcurrents.noaa.gov/slregional/regional_index.html?region=eg 3 https://www.star.nesdis.noaa.gov/sod/lsa/SeaLevelRise/LSA_SLR_timeseries_regional.php TOPEX, Jason-1, and Jason-2, seasonal signals removed

B-3 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. agreement with the larger regional data; therefore, the St. Petersburg data was utilized for further analysis.

St. Petersburg (8726520) Eastern Gulf of Mexico Avg. Gulf of Mexico Altimetry

Figure B.3. Sea Level Rise Trends of Various Measurement Sources.

3. Future Scenarios of Mean Sea Level Both the rate and magnitude of sea level rise (SLR) are important for vulnerability and impact assessment because the time horizon is a critical factor affecting risk tolerance for coastal management actions. Although it is clear that sea levels have risen historically (Figure B.3), it is difficult to predict with certainty the extent to which sea levels will continue to rise over the coming century. This uncertainty is due primarily to the uncertainty in future greenhouse gas emissions, as well as the uncertainty in the physical response of the planet to increased concentration of greenhouse gasses in the atmosphere. For the purposes of this study, three reputable sources were investigated to determine future SLR scenarios in the vicinity of Longboat Key. Each of the sources are shown in Figure B.4. Figure B.5 – Figure B.7 display the scenarios through 2100 developed by these sources that have been regionally applied to the St. Petersburg gage. Following each of the figures is a brief summary of the methodology used to develop the potential mean sea level curves.

B-4 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

NOAA USACE IPCC

(2017) (2014) (2013)

Figure B.4. Sources of Sea Level Rise Scenario Development.

B-5 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

a. NOAA

Development of the NOAA scenarios start with estimates of the probability of global mean sea level change and underlying contributing processes, conditional upon greenhouse-gas emissions pathways (NOAA, 2017). To address the different conditions, NOAA (2012) utilizes the USACE (2014) form of mean sea level rise projections which are anchored to a specific date, and yield estimates for specific time horizons. The lowest scenario is a linear extrapolation of the historic trend of 20th century tide gage measurements. In contrast, the Highest, Intermediate-High and Intermediate-Low Scenarios represent possible future acceleration in sea level rise. To represent the non-linear trajectory of SLR in these scenarios, the future SLR is represented by the following equation: E(t) = at + bt² where: E(t) = eustatic SLR, in meters, as a function of t, relative to present mean sea level* t = time, in years, starting in 1992* a = linear historic SLR trend, in meters (0.00275 m for St. Petersburg gage) b = coefficient to represent varying scenarios b = 0.0 Linear Trend (NOAA Low) b = 2.71E-05 NOAA Intermediate Low b = 8.71E-05 NOAA Intermediate High b = 1.56E-04 NOAA High

*Present mean sea level (MSL) is determined from long-term NOAA tide gage records and is referenced to the current National Tidal Datum Epoch (NTDE) provided by NOAA. The NTDE is a 19-year period with the current NTDE being 1983 to 2001. MSL for the NTDE is the mean of hourly heights observed over the entire 19-year period. Because MSL is averaged over the 19- year NTDE, the MSL value is associated with the mid-point of the NTDE, which is the year 1992 – or more specifically July 1, 1992. Thus, this date is used as the start-point for the scenarios. For reference, the present MSL for the St. Petersburg gage is at elevation -0.28 ft NAVD88.

B-6 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

NOAA

St. Petersburg (8726520)

Figure B.5. NOAA Developed Scenarios of Sea Level Rise for St. Petersburg Gage.

b. USACE

The USACE’s (2014) method for developing SLR scenarios utilizes the same quadratic equation, but with different coefficients (b) to broadly encompass SLR into the planning, engineering, and operations process of the full range of USACE projects and systems. b = coefficient to represent varying scenarios b = 2.71E-05 USACE Low b = 7.00E-05 USACE Intermediate b = 1.13E-04 USACE High

The results are presented graphically in Figure B.6.

B-7 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

USACE

St. Petersburg (8726520)

Figure B.6. USACE Developed Scenarios of Sea Level Rise for St. Petersburg Gage. c. IPCC

The Intergovernmental Panel on Climate Change (IPCC) (2013) has developed process-based projections of climate change for the 21st century of which global mean SLR is an output. Contributions of SLR were derived from climate models that were evaluated by comparison with measured observations. The sum of projected contributions were used to develop different SLR scenarios called Representative Concentration Pathway (RCP) scenarios. Each RCP represents possible underlying (though implicit) socioeconomic conditions and technological considerations, including a low-end member (RCP2.6) requiring strong mitigation (net-negative emissions in the last decades of the 21st century), a moderate mitigation member (RCP4.5) stabilizing emissions through 2050 and declining thereafter, and a high-end, fossil-fuel-intensive, ‘business-as-usual’ emission scenario (RCP8.5). The scenarios result in various projections of sea level rise (Figure B.7).

B-8 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

IPCC

St. Petersburg (8726520)

Figure B.7. IPCC Developed Scenarios of Sea Level Rise for St. Petersburg Gauge.

To account for the spatial variation in global SLR, an ensemble of model runs were used to determine the percentage of deviation from the global mean SLR. The percent deviation around Florida (at 1 degree latitude by 1 degree longitude scale) is shown in Figure B.8. A scaling factor of +14.45% was used to represent the Longboat Key area (avg. of 16.6% and 12.3%). It is noted that the IPCC curves are based on a 1986-2005 epoch, which is 3 years after the 1983-2001 epoch used for the NOAA and USACE curves. As such, the IPCC curves were shifted back 3 years to align with the same starting point as the other two methods.

B-9 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

Figure B.8. IPCC (2013) % Deviation from Global Mean Sea Level Rise. d. Comparison

Figure B.9 displays all of the SLR scenarios considered in this initial assessment, projected out to 2100. Figure B.10 displays the same information, but in more detail for the 1990 to 2050 timeframe. In the coming years and decades, sea level is forecast to continue to rise, and likely at higher rates than have been experienced from the 1940s to the 2010s. It should be emphasized that the straightforward quadratic approach to the time evolution of SLR was utilized in developing these various scenarios in part for its simplicity; there is no scientific reason or evidence to assume that SLR will evolve in precisely this smooth manner (NOAA, 2012). Scenarios projected out beyond 2050 are highly speculative with large degrees of uncertainty, and should be viewed as such. Further, data collection over the next 10 to 20 years should give a better indication of which scenarios beyond 2050 are most likely to occur. The science associated with climate change and sea level rise projections is regularly updated, revised, and strengthened, which will assist individuals and governments with decision making in the future.

B-10 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. St. Petersburg (8726520)

Figure B.9. Sea Level Rise Scenarios for St. Petersburg Gage.

St. Petersburg (8726520)

Figure B.10. Sea Level Rise Scenarios for St. Petersburg Gage (1990-2050).

B-11 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. It is important to also note that the scenarios were not intended to provide probabilistic predictions of future changes. Rather, the scenarios were intended to describe plausible conditions that support decision-making under uncertainty, given specific assumptions about which SLR science to include in one’s risk assessment. The scenarios consider a full range of scientifically plausible outcomes, including worst-case extreme scenarios that are impossible to rule out, but have a very low probability of occurrence. For example, emerging research has provided insight into the critical role that large reservoirs of land ice – such as Greenland and Antarctica – play in global and regional SLR. Under a rapid ice sheet loss scenario, global sea levels could increase by 6+ ft by 2100; however, the likelihood of such a scenario occurring is not well understood and likely minimal. The quantitative likelihood of such extreme cases was assessed by Kopp et al. (2014) using methodological assumptions to determine that in 2100 the NOAA High scenario has a 0.1% to 0.3% chance of being exceeded, whereas the NOAA Low scenario has a 94% to 100% chance of being exceeded.

It is difficult to identify one or more scenario curves (Figure B.10) that best match the measured St. Petersburg data, due to the short comparative period (1992-2018) and due to the high frequency sea level changes that are superimposed on the long term SLR signal. Nevertheless, the trend of the St. Petersburg data appears to already disagree with the lowest and highest scenarios; Linear Trend and NOAA High, respectively. With those two curves not considered, the lower and upper boundary curves are the USACE Low (equivalent to the NOAA Int. Low) and the USACE High, respectively. As such, it is recommended that the Town consider utilizing the USACE Low and USACE High curves to establish a reasonable SLR range as a baseline planning tool. It is also recommended that the measured data be reassessed every 3-to-5 years to verify if the measured data is trending as anticipated, or if different scenarios need to be considered. This will allow the Town to refine the SLR range accordingly over time. Due to the wide variation in scenario curves out to 2100, it is also recommended the Town focus on an initial planning horizon of no more than approximately 30 years (to 2050).

Figure B.11 displays the USACE SLR scenarios out to the year 2050. The curves indicate that the MSL may rise 2 to 6 inches by 2030, 4 to 11 inches by 2040, and 6 to 17 inches by 2050. Table B.1 lists the projected MSL elevations for the USACE scenarios. The scenario elevations are provided relative to the 1992 MSL, the current 2018 MSL (+0.33 ft MSL’92; avg. of the MSL measurements over the previous 5 years), and the North American Vertical Datum of 1988 (NAVD88 or simply NAVD), which is typically used for planning and construction purposes. The projected increased SLR rates are still manageable for planning and adapting during this timeframe. Future SLR will magnify the coastal flood risks as the frequency and magnitude of coastal flooding will increase as SLR increases the base water level upon which storm surge and waves act. This assumes that any climatic changes do not implicitly increase current flood risks.

B-12 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 6” to 17” rise by 2050 4” to 11” rise by 2040 2” to 6” rise by 2030 St. Petersburg (8726520)

Figure B.11. USACE Sea Level Rise Scenarios for St. Petersburg Gage (1990-2050).

Table B.1. USACE Sea Level Rise Scenarios for St. Petersburg Gage.

Mean Sea Level Elevation Scenarios Relative to 1992 MSL (inches) Year USACE Low USACE Int. USACE High 1992 0 0 0 2030 6 8 10 2040 8 11 15 2050 10 15 21

Mean Sea Level Elevation Scenarios Relative to 2018 MSL (inches) Year USACE Low USACE Int. USACE High 2018 0 0 0 2030 2 4 6 2040 4 7 11 2050 6 11 17

Mean Sea Level Elevation Scenarios Relative to NAVD88 (inches) Year USACE Low USACE Int. USACE High 2030 2 5 7 2040 4 8 12 2050 6 12 18

B-13 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. B. Storm Surge This section presents an analysis of measured peak water levels due to storms in the vicinity of Longboat Key.

1. Measured Water Levels Just as in the case of the sea level rise analysis, there is a lack of continuous water level measurements in the immediate vicinity of Longboat Key and Sarasota Bay. Therefore, data from NOAA’s St. Petersburg gage (Station ID 8726520) is utilized to analyze peak water levels. Verified hourly water level data exists back to 1947 with few interruptions in the data set (most notably in late-1947, late-1952, and nearly all of 1964). Figure B.12 displays the water level elevations relative to NAVD.

St. Petersburg (8726520) NO DATA

Figure B.12. Water Level Measurements at St. Petersburg Gage.

2. Return Period Analysis A return period analysis of the extreme water elevation events was undertaken for the St. Petersburg measured water elevations. For this analysis, the extreme water levels were modified by subtracting the linear MSL rise trend from the original measurements. This created a data set of elevations relative to the concurrent MSL. This also allows for the return-period statistics of these values to be appropriately added to any future base sea level rise scenario.

To identify “extreme events” in the data set, a peak-over-threshold analysis was applied. The threshold value of 2.45 feet (relative to concurrent MSL) was selected to determine the extreme events which occur once per year or less (on average). Figure B.13 displays the data with the

B-14 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. peaks of each event identified by a red dot. There were 73 events during the 72- year period that exceeded the threshold.

The table in Figure B.13 lists the 10 highest peak water levels measured relative to NAVD. As expected, most of the top events are associated with the passage of tropical storms and hurricanes. The events listed are not necessarily the top events relative to the concurrent MSL. For example, Hurricane Easy in 1950 recorded a peak water elevation of +3.6 ft NAVD, ranking it the 6th highest peak water level during the time period. However, the peak water level was +4.2 ft higher than the average sea level at that time, which ranks it as the 5th largest event relative to the concurrent MSL.

Specifically analyzed in this section is the measured St. Petersburg water elevation, with the long- term linear SLR trend removed from the data. Therefore, the resulting values are theoretically relative to the MSL at the time of the measurement (referred to as the “concurrent MSL”). This allows for fair comparison of the entire time period, independent of SLR changes.

To determine the frequency of occurrence of the extreme water levels, a return period analysis was conducted on the 73 extreme events to determine the distribution of the extreme events. The data was best-fit to an Exponential and Weibull function, resulting in general agreement by both. For simplicity, results associated with the Exponential function are presented and discussed herein. Figure B.14 displays the distribution of extreme events according to associated return periods.

The return period elevations from the analysis are relative to a concurrent MSL, and can be applied to any base MSL condition or scenario. To convert the concurrent MSL elevations to NAVD, the elevations were projected onto the current (2018) MSL elevation (+0.33 ft MSL’92; avg. of the MSL measurements over the previous 5 years) and then converted to NAVD (MSL’92 is 0.28 ft below NAVD).

B-15 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. St. Petersburg (8726520) 73 events in 72 yrs Threshold = +2.45 ft MSL*

Rank Event Date Elev. (ft, NAVD) #1 H. Helena Aug 31, 1985 4.8 #2 T.S. Josephine Oct 8, 1996 4.3 #3 '82 FL Subtropical Storm Jun 18, 1982 4.2

#4 H. Agnes Jun 19, 1972 4.0 NO DATA #5 '93 Storm of the Century Mar 13, 1993 3.6 #6 H. Easy Sep 5, 1950 3.6 #7 H. Frances Sep 6, 2004 3.5 #8 H. Hermine Sep 2, 2016 3.4 #9 T.S. Debby Jun 24, 2012 3.4 #10 T.S. Gordon Sep 17, 2000 3.4 MSL* = Concurrent MSL

Figure B.13. Extreme Water Level Events at St. Petersburg Gage.

Return Pd. Water Elev. Water Elev. (years) (ft, MSL*) (ft, NAVD) 1 2.4 2.5 2 2.9 2.9 5 3.4 3.5 10 3.8 3.9 20 4.2 4.3 30 4.5 4.5 40 4.7 4.7 50 4.8 4.9

MSL* indicates that the elevations are relative to a concurrent MSL datum.

Best Fit Exponential F’n (f’n relative to concurrent MSL) y = 0.6034 Ln(x) + 2.437 St. Petersburg (8726520) R² = 0.9874

Figure B.14. Return Period Analysis from the St. Petersburg Gage.

B-16 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

The return period elevations were compared to other return period analysis elevations that were developed for the area (Table B.2). The three other sources listed were developed using statistical analysis of output generated by numerical models simulating wave and water level conditions. The modeled return period elevations agree fairly well for the higher frequency events (more frequent than a 10-yr event); however, the return period elevations for the lower frequency events are significantly higher than those calculated from the St. Petersburg gage.

Table B.2. Various Water Elevation Return Period Analyses.

Water Elevation (ft, NAVD)

St. Pete FDEP H-F FEMA Dean & Return Pd. Gauge Study Flood Ins. St. Chiu (years) (1947- 2018) (Sarasota N) (Sarasota B.P.) (Sarasota N) 1 2.5 - - - 2 2.9 - - - 5 3.5 3.3 3.1 - 10 3.9 5.3 4.4 6.6 20 4.3 7.0 - 9.6 30 4.5 8.2 - - 40 4.7 - - -

50 4.9 9.5 8.3 12.3

For a perspective of flood elevations of recent significant events, the water level measurements during Tropical Storm Debby in June 2012 are presented in Figure B.15. The St. Petersburg tide gage recorded a maximum water level of +3.4 ft NAVD during the storm. This peak water elevation classifies this storm as just below a 5-yr flooding event. In other words, an event similar to Tropical Storm Debby can be expected every 5 years or so, on average. Alternatively stated, there is a 1 in 5 chance (20%) in any given year that a peak surge similar to the one experienced during Tropical Storm Debby will occur. It is noted that part of Tropical Storm Debby’s significance was that the elevated seas lasted for 4 consecutive high tide cycles, each above +3.0 ft NAVD. It is emphasized that this study only analyzed peak water levels, and not duration of flooding.

B-17 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

Figure B.15. Measured Water Levels During Tropical Storm Debby in June 2012.

3. Historical Extreme Events

As indicated in Table B.2, the expected elevations from extreme events are lower than those forecast by the FEMA Flood Insurance Study. One of the reasons for these lower values is that the Longboat Key area has not experienced the direct impact of a major land falling hurricane in a relatively long time. Nevertheless, newspaper articles and anecdotal accounts indicate that extreme water levels have occurred which impacted Longboat Key prior to most of the development (Ref. www.longboatkeyhistory.com and www.sarasotahistoryalive.com). Three events of note that took place prior to the establishment of the St. Petersburg water level gage are listed below:

4. Conclusions

B-18 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Longboat Key through overtopping of low bulkheads, and backflows through unprotected stormwater pipes. Once the flooding begins, there are increased challenges to providing emergency (police, fire) services, and the potential for flooding of non-flood code compliant structures will increase.

C. Rainfall This section presents a brief analysis of rainfall totals in the vicinity of Longboat Key. Rainfall analysis is included in this study to gain perspective of the magnitude and frequency of extreme rainfall events, and to investigate if these events are becoming more intense or more frequent.

1. Measured The closest reliable long-term rain gauge with easily-accessible daily rainfall data is located in Bradenton, FL (ID: USC00080945). The gage is operated by NOAA and has been consistently collecting daily rainfall totals since 1965 with very few interruptions. According to the station’s equipment history, a standard rain gage has been used at this location since March 1988. Prior to this time, the equipment type is listed as “Unknown”. Figure B.16 displays the daily rainfall totals for the Bradenton gage.

Due to the high spatial variability of rainfall, a dataset encompassing a larger regional area was also investigated. The Southwest Florida Water Management District (SWFWMD) has district- wide monthly rainfall totals dating back to 1915 (SWFWMD, 2018). Figure B.17 illustrates the monthly rainfall totals for the SWFWMD.

Bradenton (USC00080945)

Figure B.16. Daily Rainfall Totals for Bradenton, FL.

B-19 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

SWFMD (Monthly; District-wide)

Figure B.17. Monthly Rainfall Totals for the SWFWMD.

2. Threshold Analysis To identify “extreme events” in each data set, a peak-over-threshold analysis was applied. In an effort to include events that occur once per year or less (on average), threshold values of +3 inches (in a day) and +10 inches (in a month) were utilized for the Bradenton and SWFWMD data, respectively. Figure B.18 and Figure B.19 show the data sets with the extreme events identified with cyan dots, and the top 10 events identified with red dots. The Bradenton data has a relatively consistent frequency of extreme events; however, the magnitude of the events appear to be significantly more intense since about 1988. This sudden increase in magnitude is likely due to the change in gage equipment that was documented in March 1988. With the understanding that the Bradenton equipment was changed in 1988, there does not appear to be a clear trend in the magnitude or frequency of extreme rainfall events. Likewise, the SWFWMD data (Figure B.19) does not indicate that there is a clear increase in the magnitude or frequency of extreme rainfall events.

B-20 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Bradenton (USC00080945) 74 days in 53.3 yrs Threshold = 3 inches

Top 10 Days

Figure B.18. Peak Daily Rainfall Totals for Bradenton, FL.

SWFMD (Monthly; District-wide) 70 months in 103 yrs Threshold = 10 inches

Top 10 Months

Figure B.19. Peak Monthly Rainfall Totals for the SWFWMD.

B-21 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE AND RECURRING FLOODING

APPENDIX C: Work Completed by the Town

The Town has planned and implemented actions over the years to address many components of a plan to reduce vulnerability and increase resiliency of the Town. These actions are briefly summarized in the following sections.

A. Critical Facilities The Town’s Flood Plain Management Plan defines critical facilities as those structures from which essential services and functions for victim survival, continuation of public safety actions, and disaster recovery are performed or provided. The Town’s Plan includes a list of specific critical facilities and infrastructure (not meant to be a comprehensive list), as follows: Town of Longboat Key:  Town Hall  Fire Stations  Police Station  Public Works Complex  Waste Water Lift Stations and system: o Lift Station D  Utilities Department Water Storage Tank locations and distribution: o Mid-Key Water Plant o South-Key Water Plant Private and Commercial:  U.S. Post Office Federal government facility  Publix Supermarket Post event food/water distribution site  CVS Pharmacy Post event medical needs  Mobil Gas Station Fuel distribution  Bank of America Financial  SunTrust Bank Complex Financial, insurance, property management  First Bank Financial  Marinas Vessel recovery, fuel distribution  Mediterranean Plaza Property management and insurance

Over the last few decades, Town Hall, the north fire station, police station, and public works building were replaced with structures that meet current (at the time) flood and building code requirements. Fortunately, these facilities have not been tested under extreme wind loads, and have not been subject to flooding. There is no backlog of Town buildings that requires immediate replacement or upgrades. The south fire station is in the initial stages of design for a planned

C-1 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. replacement. The existing station was built and dedicated in 1984. As a result of a feasibility study conducted in 2016 by Town staff and a selected architectural firm, the current station is in need of replacement due to its age, size, apparatus bay square footage, and living and office space needs. The new station will be designed to current flood elevation and structural design standards and construction should be completed during the 2020/21 budget cycle.

Similarly, the sewer system and lift stations have been upgraded over time to better meet the requirements of a resilient system. The resiliency of this system was “tested” during the passage of Hurricane Irma in 2017 and the subsequent loss of power at the primary pump station (lift station D – shown below) and at 38 of 48 local lift stations. Due to the adequate supply of backup power and the staff capabilities to operate the system, there was no loss of sewer service for a five to seven day period until full power could be restored. During this system test, three additional Lift Station D. Note the elevated structure with storage of portable power units under the main portable generators were required (borrowed) to structure. fully operate the system. As a result of this lesson learned, Town staff is evaluating the need for additional portable generators or bypass pumps. The proposed undergrounding of the electrical grid within the Town will further protect the Town from local power losses. While Hurricane Irma tested the ability of the sewer system to operate without local power for an extended time, the system has not experienced a significant flooding event which may impact some of the local lift stations, whose control panels are not flood proof.

The Town of Longboat Key purchases its potable (drinking) water from the Manatee County Utilities Department where it is treated for consumption prior to delivery to the Town. The water is a blend of purified groundwater and purified surface water. Groundwater is pumped from the Florida Aquifer from seven, 1,200-foot deep wells located in eastern Manatee County. This water is pumped approximately 13 miles to the Purification Plant. Surface water is also taken from the Lake Manatee Reservoir located in central Manatee County. The treated water is pumped from the Purification Plant to the Town’s Mid-Key and South-Key water storage tanks for distribution. The Town’s mid-Key tank has a storage capacity of 1.5 million gallons, and the South-Key tank, located next to Quick Point Nature Preserve, has a capacity of 1 million gallons. The Town recently completed a replacement of the water main under Longboat Pass. The water can fill the storage tanks from the water pressure provided by Manatee County, however, there is a submersible booster pump at the Mid-Key plant to supplement the flow, if needed. The control panel of the booster pump, and all other critical components of the station, are compliant to the Town’s building code elevations (base flood elevation + 1 foot freeboard). A detailed evaluation

C-2 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. of the vulnerability of the Town’s water utility infrastructure is beyond the scope of the initial assessment report, and can be further investigated during subsequent planning efforts.

An assessment of the private and commercial critical facilities identified in the Town’s Flood plain Management Plan is beyond the scope of this initial assessment report. These facilities may be considered for inclusion in the Vulnerability Assessment (Phase 2).

B. National Flood Insurance Program and Community Rating System Flood insurance in Florida can be obtained in communities that participate in the National Flood Insurance Program (NFIP). In order to maintain compliance with the Code of Federal Regulations requirements involved with the NFIP, the Town has adopted and implemented a Flood Control Ordinance, Chapter 154 of the Town Code, effective March 17, 2014. This floodplain management ordinance also meets the credit criteria requirements for the Community Rating System (CRS). Participation in the CRS program incidentally provides homeowners discounts on federal flood insurance premiums. This program documents building and flood code compliance for new and substantially improved existing structures. As of October 1, 2016, the Town of Longboat Key is rated a Class 5 community, with ten being the worst rating, and one being the best. This rating allows residences who purchase flood insurance through the NFIP program to receive a 25% discount if their property meets all of the qualifications of the Homeowners Flood Insurance Affordability Act of 2014. The Town improved (lowered) its Class rating from 6 to 5, as of the 2016 rating.

C. Building Codes and Local Ordinances As part of the Town of Longboat Key Municipal Code, the Town has adopted Ordinances to establish minimum standards and requirements for land management, building standards, and redevelopment to ensure public safety and minimize flood damage to public and private property. Some applicable chapters of the Town’s Municipal Code regarding the aforementioned efforts are listed below. These chapters may need to be reviewed and possibly amended in light of the sea level rise and recurring storm event data presented in this report.  Chapter 150 – Buildings  Chapter 151 – Shoreline Construction  Chapter 152 – Dredging and Filling  Chapter 154 – Flood Control  Chapter 158 – Zoning Code  Chapter 159 – Post-Disaster Redevelopment Plan

D. Hurricane Plan The Town of Longboat Key has a comprehensive Hurricane Plan that applies to all Town departments and divisions. The Plan rolls the Town into a sub-unit of each County’s plan rather than being “stand-alone” as defined in F.S. 252.38(2). The basic building block of the Town’s

C-3 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Hurricane Plan is a departmental matrix that lists the departments’ responsibilities within various timeframes. The Town recognizes that the Hurricane Plan will continuously need to be reviewed and revised as new information becomes available, best practices are developed, or as conditions change. The general purpose of the Hurricane Plan is:

 To guide Town employees before, during, and after an emergency event regarding their departmental duties.  To develop and describe a comprehensive program that sets guidelines to mitigate against, prepare for, respond to, and recover from, the effects of a tropical storm event impacting the Town of Longboat Key.  To provide a framework to help minimize the loss of lives, prevent injury, protect property, safeguard the environment and preserve the local economy in the event of a disaster.

E. Beach Management Plan The Town’s existing Beach Management Plan (CPE, 1995, 2008) identified the design width and elevation of the minimum beach that the Town should maintain to prevent wave and storm surge induced erosion from impacting private development and public infrastructure. It was reported by Town staff that an update to this beach management plan is currently being developed for the Town’s consideration. As sea level rises, the berm elevation will need to be raised and a small volume of additional sand will need to be added to the beach to offset the effects of sea level rise.

The recurring storms that threaten the Town also suggest that a comprehensive review of the dunes within the Town be performed to determine their elevation, width, and vegetated condition. Dunes serve as a reservoir of sand to combat erosion during severe storm events, and can prevent direct overland flows of storm surge. One such overtopping event occurred during Tropical Storm Debby (2012) in the vicinity of Gulfshore Drive (J. Linkogle, personal communication). A minimum dune elevation and cross section should be considered as part of the beach management plan to guard against storm surge flooding during low frequency events. Depending on the results of this investigation, dune enhancement for storm protection and resiliency should be considered.

Greer Island is a Manatee County passive park that serves a wide variety of purposes to Town residents, County residents, and visitors. The Town should consider working with Manatee County to evaluate if improvement of its storm protection capabilities (beyond those stabilization measures currently being considered by the Town) is beneficial to the Town and feasible within the park’s zoning and land use restrictions.

C-4 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE AND RECURRING FLOODING

APPENDIX D: Vulnerabilities and Preliminary Considerations

During the course of this initial assessment, select vulnerabilities and concerns were identified that may occur as a result of sea level rise and/or recurring storm events. This list is preliminary and additional items may be identified by the Town in future phases of the adaptation planning effort. The concerns are listed in no order of severity or urgency. For each concern presented below, a preliminary consideration is also identified, as well as the identification of potential responsible entities. In developing this list, the concerns were reviewed to determine if the proposed actions could be accomplished within the resources and character of Longboat Key.

1. Concern: There is a lack of local water level measurements in the vicinity of Longboat Key and Sarasota Bay to track local water levels long-term. The information gathered from consistent long- term record keeping will be the basis for future decision making. HDR (2017) recommended similar water level measurement and notification system for elevated water levels to the City of Sarasota.

Preliminary Consideration: The Town should work with its governmental partners to design and implement a long term water level measurement system. System should have redundant power and or data storage capabilities. Location(s) should be investigated that best meet the needs of the communities. Upon collection of a wide range of A NOAA water level monitoring station with an measurements, correlation studies should be acoustic sensor on Dauphin Island, Alabama. performed with existing NOAA gages at Port (Photo courtesy Morgan McHugh via Climate.gov.) Manatee and St. Petersburg.

Responsible Entity: Town of Longboat Key, Manatee County, Sarasota County, City of Sarasota, SWFWMD, NOAA.

D-1 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 2. Concern: Low-lying streets susceptible to flooding may impede access for emergency vehicles during heavy rains and/or high water events. Low-lying areas of Gulf of Mexico Drive (GMD) most susceptible to flooding include three known areas: 1) 4600 block of GMD near Zota and Casa Del Mar beach resorts, 2) 5000 block near Club Longboat, and 3) 5400 block near Centre Shops of Longboat Key. There are many low- lying streets susceptible to flooding within the Street flooding along Gulf of Mexico Drive 5000 northern neighborhoods of Longboat Key, such as block near Club Longboat following heavy rains Broadway Street, Tarawitt Drive, and the back (YourObserver.com August 28, 2017). streets of Twin Shores (amongst others). During our meetings with Town staff, the Police Chief estimated that there are approximately 10 to 15 days a year where flooded roads in The Village are impassable with a standard police cruiser.

Preliminary Consideration: The Town should coordinate with FDOT to evaluate the capacity and the redundancy of the existing stormwater treatment design along these areas of GMD. Town and/or FDOT should implement stormwater Broadway Street flooding from winter storm on improvements through design, permitting and January 17, 2016. (YourObserver.com) construction at these locations of GMD.

For the neighborhood streets that experience recurrent flooding, the Town should continue its efforts to improve stormwater management design within these areas by installing/evaluating backflow prevention devices, where necessary. A comprehensive stormwater evaluation may be necessary in some areas. A detailed comparison of road and land topography should be performed to evaluate water level elevations that may trigger changes in emergency response.

To traverse flood waters during extreme high water events, such as Tropical Storm Debby, Town police have used kayaks or borrowed high-water vehicles from Manatee County. The Town may want to consider purchasing its own high-water vehicle to assist in providing emergency services to its residents.

Responsible Entity: Town of Longboat Key, FDOT.

D-2 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 3. Concern: Nuisance flooding (“sunny day flooding”) of select roads and adjacent lands caused by backflow of water into existing stormwater pipes during routine high astronomical tides (spring tides) and/or small-scale storm surges.

Preliminary Consideration: The Town should complete an inventory of all stormwater road inlet elevations and discharge outlet invert elevations. The inventory will include documentation of existing backflow prevention efforts and the performance of those systems. The Town should install backflow prevention devices within the stormwater system (at the outlets, or inline), as appropriate, to prevent street and adjacent land flooding. The Town should develop and implement a maintenance program for the backflow devices to maximize their effectiveness.

Lois Avenue looking north on September 7, 2018 Responsible Entity: Town of Longboat Key. at 9:50 am. Measured tides at Port Manatee were about 0.3 feet higher than the predicted (spring) tide.

Time of photo

Predicted and measured tides at Port Manatee (98726384) for September 6-8, 2018 (tidesandcurrents.noaa.gov). Peak high tide on September 7, 2018 was predicted at 11:42 AM.

D-3 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 4. Concern: Many of the developed properties in the northern half of Longboat Key have low bulkheads. These bulkheads will not prevent overtopping in high frequency events and may allow tidal waters onto adjacent lands and possible low lying developments. Some bulkheads are extremely porous resulting in soil being lost when water enters the property. Some canal properties do not have bulkheads, but instead have a mangrove fringe. The gap in the continuous structures along a channel can result in flood waters entering adjacent properties behind their bulkheads.

Preliminary Consideration: Several actions Low bulkhead in the Village of Longboat Key. should be considered as follows: (1) The Town should consider modifying its bulkhead ordinance to include a minimum bulkhead elevation for all properties; (2) The Town should also develop flood management strategies for addressing properties with mangrove fringes; and (3) The Town should review its Shoreline Construction ordinance (Chapter 151) to determine if future efforts to better manage flood waters are consistent with the restrictions of the ordinance, or if bulkhead raising can be designed to be compatible with natural shoreline protection efforts. Discontinuous bulkhead elevations. Responsible Entity: Town of Longboat Key, individual owners, condominium associations.

Soil loss from behind a bulkhead.

D-4 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 5. Concern: The Town has approximately 79 Repetitive Loss Properties, and an additional 574 structures of similar construction and elevations as those structures that have suffered flood losses (LBK FPMP, 2015). The figure below displays areas of Repetitive Loss Properties and like structures, highlighted in yellow. The Town also has a significant number of structures that were constructed prior to adoption of a Flood Insurance Rate Map (FIRM), and do not meet the minimum Base Flood Elevations (BFE) requirements, which are commonly referred to as PRE-FIRM structures. Of the total reported flood losses in the Town, 95% were from PRE-FIRM structures. During storms, flooding of these properties may occur which may result in displacement of residents, economic loss to individual owners, potential economic loss to condominium associations, and potential loss of tax base to the Town and County governments.

Preliminary Consideration: The Town should notify the individual owners (574) annually of the risks that they are living with, and to encourage them to obtain flood insurance. The Town should amend its website to include a general summary of potential storm risks of living in the Town.

The Town should investigate the potential for impacting roads, land, and property to determine the magnitude of impacts from recurring storm events with and without sea level rise.

Responsible Entity: Town of Longboat Key, individual owners.

Source: Town of Longboat Key Floodplain Management Plan (2015)

D-5 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 6. Concern: Under present Town ordinances, small-scale renovations to non-flood compliant structures are permitted without triggering flood elevation requirements of the structure – so long as the renovation cost does not exceed 50% of the 4 value of the existing structure. Image from Florida Adaptation Planning Guidebook (FDEP, 2018). Observations from Town staff suggest that there is insufficient incentive to raise the elevation of non-compliant structures, or to initiate redevelopment of the property to meet current flood standards. Therefore, a high number of non-flood compliant structures will remain until a significant flooding event occurs. These structures may represent an increased burden on Town resources (emergency, public works, planning, and building departments) during and after a significant flooding event, when compared to flood compliant structures.

Preliminary Consideration: To safe guard health and safety of the residents, the Town should evaluate possible ways to incentivize redevelopment of non-flood compliant properties through public education, code amendment, building permit fee rebates, or other incentives.

Responsible Entity: Town of Longboat Key, individual owners.

7. Concern: Evacuations of Town residents through adjacent islands may become challenging with the effects of sea level rise affecting adjacent communities. The Town has two evacuation routes from the island: (1) the southern route is Sarasota New Pass Bridge onto Lido Key, through St. Armands Circle to the Ringling Causeway Bridge, which leads to downtown Sarasota, and US Highway 41; and (2) the northern route, over the older two-lane Longboat Key Bridge, and Cortez Bridge through Bradenton Beach and Manatee County. These are the evacuation routes to inland locations or Interstate 75 for the residents of Longboat Key.

4 Renovations (including phased renovations) that exceed 50% of the value of the existing structure require compliance with the flood codes. Home additions are also required to be flood compliant under present Town ordinances.

D-6 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Along the southern route, the greatest concern is the ability to travel through existing low lying areas which have traditionally been susceptible to Longboat Key flooding. Known areas susceptible to flooding include streets around St. Armands Circle and John Ringling multiple sections of John Ringling St. Armands Blvd/Cswy Boulevard/Causeway between St. Armands Circle Circle and the intersection of US 41. The City of Sarasota Lido Key has implemented a stormwater pump system on Lido Key (St. Armands Circle) to reduce the effects of stormwater on the road and upland infrastructure. The stormwater assets are maintained by Sarasota County through an interlocal agreement signed with the City of Sarasota in 1998. Further improvements to the stormwater system are recommended by HDR (2017). Flooding of the intersection of Ringling Causeway and US 41 is documented5 and improvements to the intersection are part of the John Ringling Causeway during T.S. Colin (SNN News, June 7, 2016). City’s adaption plan (HDR, 2017).

St. Armands Circle

Sarasota County hurricane evacuation map excerpt (http://mediad.publicbroadcasting.net/p/wusf/files/201709/sarasota_county_evacuation_zones.pdf)

5 http://www.mysuncoast.com/news/local/road-closures-due-to-flooding-around-the-suncoast/article_8d3190bc-8b3e-11e7-9756-a7161d9963e1.html https://www.yourobserver.com/article/officials-target-u-s-41-flooding-issues

D-7 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. Gulf Drive South

Manatee County evacuation levels map excerpt (https://www.mymanatee.org/UserFiles/Servers/Server_7588306/File/Departments/Public%20Safety/Emergency%20Manag ement/Evacuation%20Levels/EM_EvacuationLevels_11x17web.pdf)

Evacuation northward from the Town of Longboat Key includes crossing the Longboat Pass Bridge and entering the southern end of Anna Maria Island. Unlike within the Town, where Gulf of Mexico Drive generally follows a historic sand ridge, Gulf Drive South (SR 789) is landward of the primary dune system and it is not located on a significant sand ridge. The road is subject to flooding during rain events. FDOT and local communities have been undertaking several projects to improve the road including better management of stormwater.6 Nonetheless, portions of Anna Maria Island are subject to back bay flooding which may affect the ability to evacuate or re-enter Longboat Key. At present, the weather services are providing significant advanced warning of potential recurring storm events along coastlines. Similarly, the County EOCs are providing evacuation notices well in advance of the minimum evacuation times. This enables the opportunity to evacuate prior to arrival of the storm surge, but not necessarily the rainfall. In addition, the effect of these low lying evacuation routes, may not be just during the evacuation of residents prior to the storm, but in addressing stormwater and debris after major storm events when re-entering the Town is desired.

Preliminary Consideration: The Town should work with adjacent communities to improve the storm protection and resiliency of the official hurricane evacuation routes.

Responsible Entity: Town of Longboat Key, Manatee Co., Sarasota Co., City of Sarasota, FDOT.

6 https://www.mympo.org/images/PDF/projectpriority/2018-project-priority-applications-for-FDOT-2-2-18/Barrier-Islands/bradenton-beach/SR789- Complete-Street-Improvements.pdf

D-8 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 8. Concern: There could possibly be negative economic effects on the real estate market within the Town, or portions thereof, due to sea level rise and recurring flooding. Lower real estate values could affect the tax revenue collected by the Town.

Preliminary Consideration: The Town should perform an economic analysis of the effect of current and projected sea level rise may have on property valuations and the potential for impacts to the tax base of the Town and the Counties. As noted previously, the potential for impact from a recurring event may be more severe in terms of flooding private developments than frequent sunny day floods of streets in the short term. Sunny day flooding in the Village neighborhood on September 7, 2018. Responsible Entity: Town of Longboat Key.

9. Concern: Florida law provides that, with some exceptions, anyone selling a home must disclose any facts or conditions about the property that have a substantial impact on its value or desirability and that others cannot easily see for themselves (See, Johnson v. Davis, 480 So.2d 625 (Fla. 1985). It was reported during our public information meetings that the local real estate industry is uncertain of how to appropriately and adequately comply with real estate disclosure laws for properties vulnerable to sea level rise and recurring flooding from future storm events.

Preliminary Consideration: The Town should utilize this report, related reports or plans, and any subsequent planning efforts to develop a frequently asked questions sheet for property owners, real estate agents, and prospective buyers regarding what is known about sea level rise and recurring flooding as it relates to Longboat Key real estate. The Town could make this information available via their website, at Town hall, and/or distributed through local real estate agents.

Responsible Entity: Town of Longboat Key, individual owners, condominium associations.

D-9 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 10. Concern: As sea levels rise, the frequency and magnitude of coastal flooding will be magnified as sea level rise increases the base water level upon which storm surge and waves act. Increased sea levels will also cause the groundwater tables to rise, which will reduce the land’s capacity to store rainfall and stormwater runoff. Extreme events will have the potential to inundate non-flood compliant homes that have never been inundated before. Over the long term (decades), the Village, including all homes and businesses accessed from Broadway Street, may require additional or more comprehensive engineering and planning to sufficiently prevent frequent or extreme flooding of streets and/or private property and structures. Additional efforts may also be required for the neighborhoods of Sleepy Lagoon, Spanish Main, Jungle Queen/Tarawitt/St. Judes, and other low- lying bayfront neighborhoods/streets (primarily Bayside Drive and Broadway Street looking located in northern portions of Longboat Key). north on September 7, 2018 at 10:40 am. Incremental large-scale protection efforts through Measured tides at Port Manatee were about 0.3 improved stormwater management may include, feet higher than the predicted (spring) tide. but are not limited to, backflow prevention, continuous seawall raising, dike construction, local pump and pump stormwater systems, or similar actions to prevent flooding.

Preliminary Consideration: A preliminary design study should be undertaken to determine what private and public actions might need to be taken to implement community-wide protection. Included in this analysis will be conceptual benefits and costs of such actions to private and public entities. Existing stormwater improvement studies may serve as a basis for part of this work, Lyons Lane. such as the recently completed Stormwater Evaluation and Analysis Peer Review for the Village (Kimley-Horn, 2018).

Responsible Entity: Town of Longboat Key.

D-10 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 11. Concern: Over the long term (decades), sea level rise and recurring storm events may affect the Town’s undeveloped islands within Sarasota Bay and open space parks, including Sister Keys, Bayfront Park, Durante Park, Quick Point Nature Preserve, and Overlook Park.

Preliminary Consideration: The Town should undertake a feasibility study to ascertain the potential impact to the Town’s undeveloped islands, and open spaces and to identify possible protection or mitigation measures. The study shall be compliant with the requirements of Sister Keys (Google Earth) Town’s Conservation and Coastal Management (CCM) elements:  CCM Policy 1.3.1: Support the initiatives and programs of the Sarasota Bay Estuary Program (SBEP) to restore shoreline and wetland habitats and to eliminate further losses.  CCM Strategy 1.3.1.1: Collaborate with the SBEP to implement its Comprehensive Habitat Protection and Restoration Plan.  CCM Strategy 1.3.1.2: Develop and implement an ecosystem management plan Durante Park (Town website) for Sister Keys.

Responsible Entity: Town of Longboat Key.

Overlook Park (Town website)

D-11 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 12. Concern: During discussions with Town staff, it was identified that the current Town codes may be silent or partially silent as to how redevelopment of low lying residential areas may occur in the event of widespread impacts to the neighborhoods occurring during a severe flood or storm event.

Preliminary Consideration: Town shall review existing codes and propose revisions or amendments as appropriate for consideration by the Commission.

Responsible Entity: Town of Longboat Key.

Example of low lying development: Twin Shores

- South Drive looking east.

13. Concern: The Town relies on Manatee County to supply potable (drinking) water to the Town’s water storage tanks. Therefore, resiliency and susceptibility to sea level rise and storm events of Manatee County’s infrastructure affects the Town’s ability to receive drinking water. According to Town staff, the Town has a water connection to Sarasota as well that can be used in the case of an emergency.

Preliminary Consideration: As a major consumer of Manatee County’s water, the Town should monitor the County’s efforts to assess/improve the resiliency of this critical asset.

Responsible Entity: Town of Longboat Key, Manatee County.

Manatee County water treatment plant located in Bradenton on Lake Manatee

D-12 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. 14. Concern: Continued increases in flood insurance premiums (potentially significant increases) may trigger some homeowners to drop their coverage (if they do not hold a federally backed mortgage). If homeowners are required to carry flood insurance (due to having a federally backed mortgage), increases in premium costs may trigger some homeowners to move off the island where flood insurance costs are less.

Preliminary Consideration: The Town should continue to participate in the National Flood Insurance Program Community Rating System, which gives homeowners discounts on flood insurance. As of October 1, 2016, the Town of Longboat Key is rated a Class 5 community, with ten being the worst rating, and one being the best. This rating allows residences who purchase flood insurance through the NFIP program to receive a 25% discount if their property meets all of the qualifications of the Homeowners Flood Insurance Affordability Act of 2014. Homeowners should take the necessary steps to ensure compliance and eligibility for the discount. The Town should continue efforts to maintain its Class 5 rating, and look for ways to improve (lower) its rating to maximize discounts for homeowners. For reference, an additional 5% discount is realized for each Class improvement, maximizing at a 45% discount for Class 1 rating.

Responsible Entity: Individual owners, Town of Longboat Key.

D-13 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. TOWN OF LONGBOAT KEY, FLORIDA INITIAL ASSESSMENT TO ADDRESS SEA LEVEL RISE AND RECURRING FLOODING

APPENDIX E: Funding Opportunities

The most applicable funding opportunities that may fit some of the Town’s needs are provided below. A detailed review of these funding programs has not been evaluated. These potential funding opportunities were outlined from various sources, including primarily the Florida Adaption Planning Guidebook (FDEP, 2018). New grant opportunities and the availability of funds constantly change. As such, it is important to continue to monitor for current grant opportunities. The following are provided in no order of significance, applicability, or monetary value:

EPA Coastal Program. The U.S. Fish and Wildlife Service (FWS) Coastal Program partners with communities to provide technical and financial assistance to assess, protect, and restore or enhance priority coastal habitats for the benefit of fish and wildlife. The program is delivered through a network of 24 field offices in priority coastal habitats along the Atlantic, Pacific, Gulf of Mexico coasts, and in the Great Lakes. Program biologists provide restoration expertise and financial assistance to federal and state agencies, local and tribal governments, businesses, private landowners, and conservation organizations such as local land trusts and watershed councils.

FEMA Community Disaster Loan Program. The Federal Emergency Management Agency (FEMA) provides direct loans to local governments to offset the loss of tax or other revenues as a result of a major disaster. The local government must demonstrate a need to maintain local governmental functions such as police and fire protection, or water and sewer services. Loans are not to exceed 25% of the local government’s annual operating budget for the fiscal year in which the major disaster occurs, up to a maximum of $5 million. To apply: The State’s Governor requests a Presidential declaration of an emergency or disaster. An applicant should consult the office or official designated as the single point of contact in the state for more information on the process. Upon declaration, one may apply for assistance through the Governor’s authorized representative.

FEMA Flood Mitigation Assistance Grant Program. FEMA provides funds to local governments, tribes, and some non-profits to reduce or eliminate claims made under the National Flood Insurance Program (NFIP). Specifically, the program aims to reduce the number of repetitive loss structures insured by NFIP. (Repetitive loss structures are those that have sustained two or more losses, each exceeding $1000, within a ten-year period.) There are three types of grants that fall within the Flood Mitigation Assistance (FMA) program area: 1. Planning Grants to prepare flood mitigation plans; 2. Project Grants to implement measures to reduce flood losses, such as elevation, acquisition, or relocation of NFIP-insured structures; 3. Technical Assistance Grants for the state to help administer the FMA program and activities. To apply, projects should

E-1 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. be submitted as the need arises to the state which then selects applications based on predetermined priorities set forth in a disaster specific Mitigation Strategy to send to FEMA for final approval. More information can be found at: https://www.fema.gov/flood-mitigation-assistance-grant-program

FEMA Hazard Mitigation Grant Program. FEMA provides funds to local governments, tribes and some non-profits to reduce the loss of life and property due to natural disasters and to enable mitigation measures to be implemented during the immediate recovery from a disaster. Grants given through the states to local governments following an official Presidential disaster declaration are used to implement long-term hazard mitigation measures that provide a long-term solution to a specific risk. For example, the grant could be used to elevate flood-prone homes or businesses, thus allowing floodwater to flow under the house rather than through it. FEMA will pay up to 75% of the project cost, while the remaining 25% must be funded through the state, local government applicants or individual property owners. In-kind services and materials can be used. More information can be found at: https://www.fema.gov/hazard-mitigation-grant-program

FEMA Pre-Disaster Mitigation Grant Program. The Pre-Disaster Mitigation (PDM) program provides annual funding to support states, territories, Indian tribal governments, communities, and universities for hazard mitigation planning and the implementation of mitigation projects prior to a disaster event. This program promotes implementation of activities designed to reduce injuries, loss of life, and damage and destruction to property from natural hazards. Administered by the state, the Pre-Disaster Mitigation (PDM) program is a competitive federal grant program that was created to assist communities with the implementation of cost effective mitigation activities prior to disasters. The intent of this program is to reduce overall risk to people and property, while also minimizing the cost of disaster recovery. The State of Florida provides workshops to explain the purposes of the program, eligible project types and application requirements. A 25% local match is required (to the federal contribution of 75%); this is a cost reimbursement program. More information can be found at: https://www.fema.gov/pre-disaster-mitigation-grant-program

Repetitive Flood Claims Program. The Repetitive Flood Claims (RFC) grant program makes up to $10 million available annually for FEMA to provide RFC funds to states and communities to assist them in reducing flood damages to insured properties that have had one or more claims with the NFIP. FEMA may contribute up to 100% of the total amount approved under the RFC grant award to implement approved activities, if the applicant has demonstrated that the proposed activities cannot be funded under the Flood Mitigation Assistance (FMA) program.

NFWF National Coastal Resilience Fund. The National Fish and Wildlife Foundation (NFWF) National Coastal Resilience Fund is a program that funds projects that provide benefits to

E-2 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. communities, as well as for fish and wildlife. The NFWF will award grants to create, expand and restore natural systems in areas that will both increase protection for communities from coastal storms, sea and lake level changes, flooding, and coastal erosion and improve valuable habitats for fish and wildlife species. The NFWF will invest in projects in two focus areas: Project Planning and Design; and Project Implementation. This program is funded by and closely coordinated with the National Oceanic and Atmospheric Administration (NOAA) and will include input from other federal agencies and outside experts. The National Coastal Resilience Fund will award up to $30,000,000 in grants in 2018. Project awards are expected between $100,000 and $3,000,000. A minimum 1:1 non-federal match in cash or in-kind services is expected for all awards. Proposals for 2018 were due in early August. This is believed to be an annual opportunity. More information can be found at: https://www.nfwf.org/coastalresilience/Pages/home.aspx

The National Academies of Science, Engineering and Medicine – Gulf Research Program – Thriving Communities Grants 5. The National Academies Gulf Research Program seeks to help bridge the gap between the knowledge and practice of community resilience. The program seeks approaches that will advance information exchange between resilience researchers and those that seek to implement policies and practices to enhance the resilience and well-being of their communities. The program seeks to fund projects that combine high-quality research and practice components to produce a stronger evidence-base for strategies and approaches that can enhance community resilience and well-being. The Gulf Research Program accepts proposals from all types of U.S. organizations, excluding federal agencies, on behalf of qualified individuals. Total funding available is $10 million. The award duration is up to 36 months. Proposals for 2018 are due December 5. The number of awards is to be determined. Projects of any size will be considered. Resources made available will depend on the quality of the proposals received and the budgets proposed by successful applicants. More information can be found at: http://www.nationalacademies.org/gulf/grants/tc-5/index.htm?utm_source=direct&utm_medium=email&utm_campaign=2018_TC5_openchannel

National Oceanic and Atmospheric Administration (NOAA) Office for Coastal Management Coastal Resilience Grant. This competitive grant program funds projects that are helping coastal communities and ecosystems prepare for and recover from extreme weather events, climate hazards, and changing ocean conditions. All project proposals undergo a rigorous merit review and selection process by a panel of subject matter experts from across the United States that include representatives of government, academia, and private industry. Funding is typically available on an annual cycle.

FDEP Florida Resilient Coastline Program - Resilience Planning Grants. The Florida Department of Environmental Protection (FDEP), through the Florida Resilient Coastlines Program (FRCP), provides financial assistance aimed at preparing coastal Florida communities for current and future effects of rising sea levels, including coastal flooding, erosion, and ecosystem changes. The purpose of the FRCP Resilience Planning Grants (RPG) is to promote community resilience planning, the development of relevant decision support tools, and/or public outreach

E-3 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. tools, products or programs that support community resilience planning efforts. Development of vulnerability assessments, adaptation plans, and comprehensive plan goals, objectives and policies are also encouraged. The following project types are the primary aim of the grant program. 1. Compliance with “Peril of Flood” statute (Sec. 163.3178(2)(f) F.S.) for communities with a Coastal Management Element in their Comprehensive Plan. 2. Development of Adaptation Action Areas and associated Goals, Objectives, and Policies in a community’s Comprehensive Plan. 3. Vulnerability Assessments, Adaptation Plans or Resilience Plans. 4. Development of relevant decision support tools, and/or public outreach tools, products or programs that support community resilience planning efforts, including regional collaboration efforts. The FRCP announces the availability of state funds for innovative coastal projects under its RPG annually, beginning around August 1, with applications due around the beginning of September. Eligible applicants include Florida’s 35 coastal counties and the local governments within their boundaries that are required to include a coastal element in their comprehensive plan. Florida regional planning councils, national estuary programs, colleges, community colleges, and state universities may also apply, as long as an eligible local government agrees to participate as a partner. The grants are one-time, no-match funding opportunities funded through the Florida Coastal Management Program. More information can be found at https://floridadep.gov/fco/florida-resilient-coastlines-program/content/funding-opportunities

FDEP - Coastal Partnership Initiative Grant Program. The Coastal Partnership Initiative (CPI) Grant Program was developed to promote the protection and effective management of Florida's coastal resources at the local level. The Florida Coastal Management Program (FCMP) makes National Oceanic & Atmospheric Administration funds available, on a competitive basis, to eligible local governments. Eligible local governments are defined as Florida's 35 coastal counties and all municipalities within their boundaries that are required to include a coastal element in their local comprehensive plan. Florida's public colleges and universities, regional planning councils, national estuary programs and nonprofit groups may also apply if an eligible local government agrees to participate as a partner. CPI grants provide support for innovative local coastal management projects in four program areas: Resilient Communities, Public Access, Working Waterfronts, and Coastal Stewardship. Eligible entities may apply for grants for community projects such as habitat restoration, park planning and improvements, waterfront revitalization, and improving communities' resiliency to coastal hazards. Applications are accepted once a year in response to a “Notice of Availability of Funds” published in the Florida Administrative Register. The funding year typically begins July 1 and ends June 30; however, this timeframe may be shifted if the grant cycle is delayed or postponed. Projects are to be completed within one year, no matter when the funding cycle begins. Funding limits for this grant cycle is up to $25,000 for non-construction and up to $75,000 for construction. More information can be found at https://floridadep.gov/fco/fcmp/content/grants

E-4 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.

FDEP Clean Water State Revolving Fund Loan Program. The Clean Water State Revolving Fund (CWSRF) program provides low interest loans for planning, designing, and constructing water pollution control facilities. The Department solicits information each year for wastewater and stormwater projects. The information is used to establish project priorities for the following annual cycle. Funds are made available for Preconstruction Loans and Construction Loans. The Loan Terms include a 20-year amortization and low-interest rates. Preconstruction loans are available to all communities and provide up front disbursements for administrative services, project planning and project design. Cities, counties, authorities, and special districts responsible for sewerage services, stormwater management, and estuary protection are eligible for loans. The local government agency must generally own, operate, and maintain the facilities to be financed by a loan.

FDEP Florida Beach Erosion Control Program. The Florida Beach Erosion Control Program was established for the purpose of working in concert with local, state and federal governmental sponsors to achieve the protection, preservation and restoration of the coastal sandy beach resources of the state. Eligible activities of this grant-in-aid program include beach restoration and nourishment activities, project design and engineering studies, environmental studies and monitoring, inlet management planning, inlet sand transfer, dune restoration and protection activities, dune walkover construction and other beach erosion prevention related activities. All projects must be cost effective and compliant with the Florida Strategic Beach Management Plan. Up to 50% of the project costs for beach restoration projects and up to 75% for inlet management projects; other state grant-in-aid funds may not be used as a local match. The program requires submittal of funding request, including a long-range budget plan with supporting information for ranking as required by Rule 62B-36, Florida Administrative Code. Annual updates of budget plans are due September 1 of each year.

FWC State Wildlife Grants. Often this grant has a climate change, sea level rise, or resilience initiative that allows for grant funding to support an effort towards the initiative.

FDEM Residential Construction Mitigation Program. Section 215.559, Florida Statutes, created the Hurricane Loss Mitigation Program, which funds the Residential Construction Mitigation Program (RCMP). Annually, the Legislature appropriates $10 million from the Florida Hurricane Catastrophe Fund for different mitigation programs which is funded by insurance surcharges. Notice of Funding Availability (NOFA) is advertised in the Florida Administrative Weekly and all requests for proposals are issued via the www.myflorida.com Web portal. Application deadlines can also be found at www.floridadisaster.org/mitigation/rcmp/ index.htm.

Southwest Florida Water Management District - Cooperative Funding Initiative. The Cooperative Funding Initiative (CFI) is a cost-share program that covers up to 50% of the cost of

E-5 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC. projects that help create sustainable water resources, enhance conservation efforts, restore natural systems and provide flood protection. All CFI funding decisions are made by volunteer Basin Board members who are well informed on the specific resources and challenges within their individual basins. Working with local governments and community partners allows the district to leverage its investment. Approximately $25 million is available yearly. 50/50 cash cost share between the Basin Boards and the cooperator. (In-kind services not eligible as a match.)

State of Florida Pollution Control Bond Program. This State of Florida Pollution Control Bond Program provides loans to local governments for construction of water, wastewater, solid waste, stormwater and air pollution control facilities. Proceeds from bonds sold by the state provide for up to $300 million per year. Eligible entities must submit complete loan applications with plans and specs. Florida municipalities, county governments and special districts are encouraged to apply.

E-6 APTIM ENVIRONMENTAL & INFRASTRUCTURE, INC.