Draft plan update, October 10, 2025
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TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE Draft For Review October 10, 2025 Prepared by Metropolitan Area Planning Council For the Town of Winthrop TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE ACKNOWLEDGEMENTS AND CREDITS This plan was prepared for the Town of Winthrop by the Metropolitan Area Planning Council (MAPC) under the direction of the Massachusetts Emergency Management Agency (MEMA). The plan was funded by the Federal Emergency Management Agency’s (FEMA) Hazard Mitigation Grant Program (HMGP). MAPC Officers President, Erin Wortman, Town of Stoneham Vice President, Jennifer Constable, Town of Rockland Secretary, Imaikalani Aiu, Town of Weston Treasurer, Sam Seidel, Gubernatorial Executive Director, Marc Draisen, MAPC MAPC Staff Credits Project Manager/ Environment Director: Martin Pillsbury Mapping/GIS Data Services: Rachel Bower Massachusetts Emergency Management Agency Agency Director: Dawn Brantley Department of Conservation and Recreation Commissioner: Brian Arrigo Winthrop Hazard Mitigation Planning Team Name Position Anthony Marino Town Manager Cheryl McCormick Assistant Town Manager John Goodwin Police Chief Scott Wiley Fire Chief Steven Calla Director of Public Works Department Stephen Calandra Deputy Fire Chief Al Legee Building Commissioner Chris Boyce Planning Board Chair D. Baird Board of Appels Chair Kim Dimes Conservation Commission Chair Barbara Evangelista Planning Board/Board of Appeals Clerk Laurisa Wojcik Executive Assistant to Town Manager Steve Rogers Police Dept. Ferruccio Romeo Deputy Chief of Policed Meredith Hurley Director, Winthrop Public Health and Clinical Services Homeyer, Kristen Resilience Manager, N. Suffolk Resilience & Sustainability Abderezak Azib Resilience Manager, N. Suffolk Resilience & Sustainability Cover photo: Aerial view of Winthrop, Town of Winthrop Linked In page TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE TABLE OF CONTENTS Section # Section Page 1 Executive Summary 1 2 Introduction 7 3 Planning Process and Public Participation 16 4 Risk Assessment 22 5 Hazard Mitigation Goals 106 6 Existing Mitigation Measures 107 7 Mitigation Measures from the 2019 Plan 130 8 Hazard Mitigation Strategy 139 9 Plan Adoption and Maintenance 155 10 List of References 157 Appendix A Hazard Mapping 158 Appendix B Hazard Mitigation Team Meetings 174 Appendix C Documentation of Public Participation 178 Appendix D Flood Resilience Checklist for Residential Properties 182 Appendix E Documentation of Plan Adoption 188 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE LIST OF TABLES Table # Table Page 1 Plan Review and Update Process 4 2 Previous Federal/State Disaster Declarations 7 3 State Disaster Declarations since 2018 10 4 FEMA-Funded Mitigation Projects 10 5 Town of Winthrop Characteristics 13 6 Membership of the Winthrop Hazard Mitigation Team 18 7 Outreach to Winthrop Community Stakeholders 19 8 Climate Change & Natural Hazards 29 9 Hazard Risks Summary 31 10 Suffolk County Flood Events, 2005-2025 34 11 Rainfall rates for the 10-year 24-hour storm 36 12 Suffolk County Coastal Flood Events, 2006-2023 37 13 Coastal Transect Parameters for Winthrop 38 14 High Water Marks in Winthrop, Blizzard of 1978 39 15 Summary of Repetitive Losses and Claims in Winthrop 45 16 Average Shoreline Change and Uncertainty 47 17 Average Shoreline change by shoreline type 48 18 Hurricane Records for Massachusetts, 1938-2023 55 19 Enhanced Fujita Scale 57 20 Tornado Records for Suffolk County 59 21 Dolan- Davis Classification System for Nor’easters 60 22 Nor ’ easter Events for Massachusetts, 1978 - 2023 61 23 Regional Snowfall Index 62 24 Heavy Snow and Blizzard Events in Suffolk County 2010 – 2023 62 25 Winter-Related Federal Disaster Declarations, 1978-2023 64 26 Sperry-Piltz Ice Accumulation Index (SPIA®) 66 27 Beaufort Wind Scale 67 28 Suffolk County Thunderstorm Events, 2010-2023 70 29 Hail Size Comparison 71 30 Suffolk County Hail Events, 2010-2025 72 31 Richter Scale and Effects 75 32 Historical Earthquakes in Massachusetts, 1727-2023 76 33 Landslide Volume and Velocity 79 34 Suffolk County Extreme Heat Occurrences, 2010-2023 82 35 Suffolk County Extreme Cold Occurrences, 2010-2023 86 36 US Drought Monitor Compared to MA Statewide Drought Levels 88 37 Indices Values Corresponding to Drought Index Severity Levels 89 38 Chronology of major droughts in Massachusetts since 1879 91 39 Frequency of Massachusetts Drought Levels 93 40 Winthrop Land Use 95 41 Winthrop Employment by Category, 2023 96 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 42 Developments Completed Since 2015 98 43 Winthrop Critical Facilities 99 44 Estimated Damages from Hurricanes 103 45 Estimated Damages from Earthquakes 104 46 Estimated Damages from Flooding 105 47 Existing Mitigation Measures 124 48 Status of Mitigation Measures from the 2019 Plan 133 49 Mitigation Measure Prioritization 146 50 Recommended Mitigation Measures 150 LIST OF FIGURES Figure # Figure Page 1 Natural Hazards and Climate Change Overlap 7 2 Local Retail and Commercial Areas of Winthrop 11 3 Belle Isle Bridge and Winthrop Ferry 12 4 Six-Step Planning Process 15 5 Observed Increase in Temperature 22 6 Change in the Annual Number of Days Over 90 F 22 7 Change in Average Summertime Temperatures for Massachusetts 23 8 Observed Change in Annual Precipitation in the Heaviest 1% Events 24 9 Change in 2070Annual and Seasonal Precipitation Compared to Today 25 10 Consecutive dry day events (multiple-dry-day events per year) 26 11 Observed Increase in Sea Level Rise 27 12 Total Flooded Area of the Commonwealth for Selected Events 28 13 Saugus River Gage Heights, March-April 2010 33 14 Changes in Frequency of Extreme Downpours, 1948 – 2011 34 15 Suffolk County Shoreline Transect Locations for Winthrop 39 16 Projected Sea Level Rise for Greater Boston Harbor 41 17 Areas Inundated in Future Sea Level Rise Scenarios 42 18 Percent of Assessed Shoreline by Type 47 19A Long-Term Coastal Erosion in Winthrop, 1840s-2018 49 19B Short-Term Coastal Erosion in Winthrop, 1970-2019 50 20 Winthrop Shoreline Change (1847-2008) 51 21 Atlantic Based Tsunami- Potential Threat 52 22 Winthrop Shore Drive, October 28, 2012, Hurricane Sandy 56 23 Chelsea/Revere Tornado of 2014 58 24 Nor’easter Satellite Image 60 25 National Risk Index for Lightning 69 26 Depth-Duration Curve 69 27 Wildfire Risk Areas in Massachusetts 74 28 Massachusetts Earthquake Probability Map 77 29 Boston Study Region Liquefaction Potential 78 30 Heat Index Chart 81 31 Health Risks Associated with Extreme Heat 82 32 Summer 2021 Temperatures, Boston Area 83 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 33 Summer 2021 Temperatures, Boston Area 84 34 Massachusetts Extreme Heat Scenarios 85 35 Wind Chill Temperature Index and Frostbite Risk 86 36 Principal Sources and Pattern of Moisture Delivery to Massachusetts 87 37 Weeks of Extreme Drought (2001-2022) 90 38 Weeks of Extreme Drought Mapped by MA Region (2001-2017) 92 39 Recent Massachusetts Drought Events (2016-2021) 92 40 Winthrop Employment by Category, 2023 96 41 Winthrop Center Business District 97 42 Climate Change Effect on Winthrop Residents 114 43 Climate Action Plan Goals and Objectives 114 44A Managed Retreat 115 44B Beach Nourishment 115 44C Hardscape Seawall/Revetment 116 44D Nature Based Solution - Cobble 116 44E Nature Based Solution – Stormwater Parks 116 44F Nature Based Solution -Oyster Reefs 117 45 Morton and Banks Streets Hot Spot 117 46 Priority Sites Assessed 119 47 Morton and Banks Streets Flood Projections 120 48 Examples of Neighborhood Flooding, 2018 Nor’easter 121 49 Winthrop Shoreline Structures 122 50 Winthrop CRB Top Recommendations 123 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 1 SECTION 1: EXECUTIVE SUMMARY Hazard Mitigation planning is a proactive effort to identify actions that can be taken to reduce the dangers to life and property from natural hazard events. In the communities of the Boston region of Massachusetts, hazard mitigation planning tends to focus most on flooding, the most likely natural hazard to impact these communities. Other common concerns are the impacts of extreme heat, drought, and nor’easters. This plan also considers how our changing climate will affect natural hazards. Warming temperatures will fuel changing precipitation patterns and an increasing frequency and intensity of severe storms. The Federal Disaster Mitigation Act of 2000 requires all municipalities that wish to be eligible to receive FEMA funding for hazard mitigation grants to adopt a local multi-hazard mitigation plan and update this plan in five-year intervals. PLANNING PROCESS Hazard Mitigation planning is a proactive effort to identify actions that can be taken to reduce the dangers to life and property from natural hazard events. In the communities of the Boston region of Massachusetts, hazard mitigation planning tends to focus most on flooding, the most likely natural hazard to impact these communities. However, the plan focuses on all categories of natural hazards that could potentially affect the community, including those that infrequently occur. The Federal Disaster Mitigation Act of 2000 requires all municipalities that wish to be eligible to receive FEMA funding for hazard mitigation grants, such as Flood Mitigation Assistance (FMA) and the Hazard Mitigation Grant Program (HMGP), to adopt a local multi-hazard mitigation plan and update this plan in five-year intervals. This is an update of the 2015 Winthrop Hazard Mitigation Plan, which was approved by FEMA on August 3, 2015. That plan updated the Town’s original Hazard Mitigation Plan, which prepared in 2005 as part of a regional North Shore planning effort. Planning for this Hazard Mitigation Plan update was led by the Winthrop Local Hazard Mitigation Team, composed of staff from a number of different Town Departments and representatives of the North Suffolk Office of Resilience and Sustainability. This team met on the following dates focusing on various aspects of developing the updated plan: July 16, 2024 Identify and map Critical Facilities, Local Hazard Areas, and Development October 28, 2024 Review/update Existing Mitigation Measures and Hazard Mitigation Goals March 26, 2025 Review the status of recommended mitigation measures from the 2015 plan April 15, 2025 Review and finalize the mitigation strategy for the 2025 updated plan Public participation in this planning process is important for improving awareness of the potential impacts of natural hazards and to build support for the actions the Town takes to mitigate them. The Winthrop Town Council hosted two public meetings, the first on May 20, 2025, and the second on October xx, 2025. The Town Council meetings were televised locally and available on videos on You Tube. The meetings included a description of the hazard mitigation planning process, an overview of the plan and proposed mitigation actions, as well as directions on how TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 2 the public could access the draft plan on the Town website and make comments. The plan was posted online for public review, and a dedicated project email, WinthropResilience@mapc.org , was set up to receive public comments and questions. Key town stakeholders and neighboring communities were notified and invited to review the draft plan and submit comments. See Documentation of Public Meetings in Appendix C. RISK ASSESSMENT The Winthrop Hazard Mitigation Plan assesses the potential impacts to the Town from flooding, high winds, winter storms, brush fire, geologic hazards, extreme temperatures, and drought. Coastal flooding, driven by hurricanes, northeasters and other storms, clearly presents the greatest hazard to the Town. These are described in Section 4 and the locations of hazard areas are shown on the map series in Appendix A. The plan also addresses the projected future flooding impacts related to sea level rise using the state’s M assachusetts Coastal Flook Risk Model (MC-FRM). The Winthrop Hazard Mitigation Team identified 97 Critical Facilities, four more than in the 2015 plan. These are shown on the map series in Appendix A and listed in Table 43, identifying which facilities are located within the mapped hazard zones. A HAZUS-MH analysis provided estimates of damages from Hurricanes of 100-year and 500- year recurrence ($6.7 million to $28.1 million) as well as earthquakes of magnitudes 5 and 7 ($375 million to $2.1 billion). Flood damage estimates range from $236 million for a 100-year event to $334 million for a 500-year event. HAZARD MITIGATION GOALS The Winthrop Hazard Mitigation Team reviewed and discussed the goals from the previous 2015 Hazard Mitigation Plan. The Team retained the nine goals from the previous plan for the 2025 update, and endorsed the addition of five new goals (#10 – 15 below) to reflect a more comprehensive approach and to incorporate climate resiliency for this 2025 plan update. All of the goals are considered critical for the Town, and they are not listed in order of importance. 1. Ensure that critical infrastructure sites are protected from natural hazards. 2. Protect existing residential and business areas from flooding. 3. Maintain existing mitigation infrastructure in good condition. 4. Continue to enforce existing zoning and building regulations. 5. Educate the public about zoning and building regulations, particularly with regard to changes in regulations that may affect tear-downs and new construction. 6. Encourage future development in areas that are not prone to natural hazards. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 3 7. Educate the public about natural hazards and mitigation measures. 8. Make efficient use of public funds for hazard mitigation. 9. Protect the Town’s ability to respond to various natural hazard events. 10. Consider the potential impacts of climate change and incorporate climate sustainability and resiliency into hazard mitigation planning. 11. Incorporate environmental justice considerations into natural hazard mitigation, including outreach to climate vulnerable populations, identification of hazard impacts, and related mitigation measures. 12. Integrate hazard mitigation planning as an integral factor in all relevant municipal departments, committees and boards. 13. Encourage the business community, local institutions and non-profits to work with the Town to develop, review and implement the hazard mitigation plan. 14.: Work with surrounding communities, state, regional and federal agencies to ensure regional cooperation and solutions for hazards affecting multiple communities. HAZARD MITIGATION STRATEGY The Winthrop Local Hazard Mitigation Planning Team identified a number of mitigation measures that would serve to reduce the Town ’s vulnerability to natural hazard events. These are described in Section 8 and listed in Table 50. A brief summary list of recommended mitigation measures follows: • Yirrell Beach project • Complete utility elevation project in flood hazard area • Ingleside Park drainage upgrade • Lower Nahant Avenue drainage upgrade • Upgrade Bayou Street drain line • Lewis Lake drainage upgrade • Boston Harbor Drainage Outfall Headwalls / Seawalls • Consider Community Rating System application • Acquire vacant flood prone lands as or if they become available. • Ensure electrical utilities are properly maintained • Upgrade emergency generators: Town Hall/EOC • Integrate mitigation into local planning • Increase hazard education and risk awareness • Assess vulnerability to severe winds • Implement a structural retrofit program for town’s priority at risk buildings TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 4 • Incorporate drought tolerant species into regulations • Require permeable driveways to promote infiltration and reduce runoff • Incentivize hazard mitigation (Stormwater fee with incentives) Overall, the Town’ hazard mitigation strategy recognizes that mitigating hazards for Winthrop will be an ongoing process as our understanding of natural hazards and the steps that can be taken to mitigate their damages changes over time. Global climate change and a variety of other regional and local factors impact the Town ’s vulnerability, and local officials will need to work together across municipal lines and with state and federal agencies to address these changes. This Hazard Mitigation Strategy is intended to provide the Town with a “roadmap” to key actions that will improve its resilience to natural hazards. The plan ’s recommendations will be incorporated into other municipal plans and policies, such as the Open Space and Recreation Plan, , the Capital Investment Plan, and Municipal Vulnerability Preparedness 2.0. PLAN REVIEW & UPDATE PROCESS The process for developing the Winthrop Hazard Mitigation Plan 2025 Update is summarized in Table 1 below. Table 1 Plan Review and Update Process Plan Section Reviews and Updates 3 – Public Participation The Local Hazard Mitigation Team presented the planning process at two public meetings hosted by the Town Council. The first meeting was held during plan development, and the second was held when the draft plan was completed and made available online for public comment. Outreach efforts to publicize these engagement opportunities included webpage content, social media, email, flyers, and press outreach. 4 – Risk Assessment MAPC gathered the most recently available hazard and land use data and met with Town staff to identify changes in local hazard areas and development trends. Town staff reviewed critical infrastructure with MAPC staff in order to create an up-to-date inventory and GIS mapping. MAPC also used the most recently available version of HAZUS to assess potential impacts of flooding, earthquakes, and hurricanes. 5 - Goals The Hazard Mitigation Goals were reviewed and endorsed by the Winthrop Hazard Mitigation Planning Team. The goals were revised and added to in order to reflect a more comprehensive approach and to incorporate climate resiliency for this 2025 plan update. 6 – Existing Mitigation Measures The list of existing mitigation measures from the 2015 plan was updated to reflect current mitigation activities in the Town. 7 & 8 – Hazard Mitigation Strategy Mitigation measures from the 2015 plan were reviewed and assessed as to whether they were completed, in-progress, or deferred. The Winthrop Hazard Mitigation Team determined whether to carry forward recommended mitigation measures into this 2025 Plan, or TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 5 modify or delete them. The 2025 Plan's mitigation strategy reflects both new measures and those carried forward from the 2015 plan that have not yet been completed. The Winthrop Hazard Mitigation Team prioritized the mitigation measures based on current conditions. 9 – Plan Adoption & Maintenance This section of the plan was updated with an on-going plan implementation review and five-year update process that will assist the Town in incorporating hazard mitigation issues into other Town planning and regulatory review processes and better prepare the Town for the next comprehensive plan update. As indicated on Table xx, Winthrop made progress on implementing mitigation measures identified in the 2015 Hazard Mitigation Plan. Several recommended mitigation measures have been completed, including • Winthrop Shore Drive seawall • Floodplain District Management • Floodplain mapping updates • Plan for storm surge events. • Limit development in V-Zones. • Adopt coastal A-Zones. • Update building permit to add incentives for additional height above BFE • Climate change master plan update or action plan • Drainage preventive practices: vactor truck • Stormwater best practices training • Increase wetlands law enforcement practices • Digitally map storm drains and outfalls • Wetlands and Stormwater Outreach program • Update stormwater ordinance • Update tree maintenance program • Regional Sea Level Rise Action Work Group participation • Partner with utility to document hazard areas • Retrofit at-risk critical, public building roofs to withstand snow loads • Construct snow fences • ID populations vulnerable to long term power outage • Include wildfire risk and mitigation in comprehensive planning • Inspect fire hydrants on a routine basis • Require Green Building and parking best practices • Purchase new trailer-mounted light tower • Purchase two, 5kW trailer-mounted mobile generators • Upgrade radio repeater units TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 6 • Assess and map community risk • Winthrop obtained high water rescue vehicles • Winthrop obtained an inflatable rescue raft Several others are in progress or have been partially completed. Progress toward implementing these mitigation measures will be continued in this 2025 Plan Update. Moving forward into the next five-year plan implementation period there will be more opportunities to incorporate hazard mitigation into the Town ’s decision-making processes. The Hazard Mitigation Team, consisting of the Town Administrator and representatives of Public Works, Police, Fire, the Planning Board, Conservation Commission, Building Commissioner, Board of Appeals, Public Health, and the North Suffolk Office of Resilience and Sustainability, will continue a coordinating role under the direction of the Town Administrator, as described in Section 9, Plan Adoption and Maintenance. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 7 SECTION 2: INTRODUCTION PLANNING REQUIREMENTS UNDER THE FEDERAL DISASTER MITIGATION ACT The Federal Disaster Mitigation Act, passed in 2000, requires that after November 1 2004, all municipalities that wish to continue to be eligible to receive FEMA funding for hazard mitigation grants, must adopt a local multi-hazard mitigation plan and update this plan in five-year intervals. This planning requirement does not affect disaster assistance funding. Federal hazard mitigation planning, and grant programs are administered by the Federal Emergency Management Agency (FEMA) in collaboration with the states. These programs are administered in Massachusetts by the Massachusetts Emergency Management Agency (MEMA) in partnership with the Department of Conservation and Recreation (DCR). The Town of Winthrop contracted with the Metropolitan Area Planning Council (MAPC), to assist the Town in updating its local Hazard Mitigation Plan, which was approved by FEMA in 2015. The updated local plan produced under this contract is designed to meet the requirements of the Disaster Mitigation Act for the Town of Winthrop, addressing local and regional concerns and hazards that impact the Town. WHAT IS A HAZARD MITIGATION PLAN? Natural hazard mitigation planning is the process of determining how to systematically reduce or eliminate the loss of life and property damage resulting from natural hazards such as floods, earthquakes, and hurricanes. Hazard mitigation means to permanently reduce or alleviate the losses of life, injuries, and property resulting from natural hazards through long-term strategies. These long-term strategies include planning, policy changes, programs, projects, and other activities. As more is understood about the impacts of climate change, it is becoming increasingly important to recognize the relationship between climate change and many of the natural hazards addressed in hazard mitigation plans. This was addressed in the last two editions of the Massachusetts State Hazard Mitigation Plan in 2018 and the 2023. Resilient MA Plan. These plans recognizes that many hazards are being exacerbated by changing climate, and that adapting to the expected impacts of climate change is a form of hazard mitigation. Therefore, this plan incorporates consideration of future risks based on projections for increased temperatures, future sea level rise, and increased frequency and severity of extreme weather fueled by global climate change effects. Accordingly, MAPC has updated the format of this Hazard Mitigation Plan to incorporate climate considerations. Figure 1 illustrates the relationship between natural hazards and climate change. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 8 Figure 1. Natural Hazards and Climate Change PREVIOUS FEDERAL/STATE DISASTERS The Town of Winthrop has experienced 24 natural hazards that triggered federal or state disaster declarations since 1991. These are listed in Table 2 below. The majority of these events involved flooding, while eight were due to hurricanes or nor’easters, and seven were due to severe winter weather. Table 2 Previous Federal Disaster Declarations DISASTER NAME (DATE OF EVENT) TYPE OF ASSISTANCE DECLARED AREAS Hurricane Bob (August 1991) FEMA Public Assistance Project Grants Counties of Barnstable, Bristol, Dukes, Essex, Hampden, Middlesex, Plymouth, Nantucket, Norfolk, Suffolk Hazard Mitigation Grant Program Counties of Barnstable, Bristol, Dukes, Essex, Hampden, Middlesex, Plymouth, Nantucket, Norfolk, Suffolk (16 projects) No-Name Storm (October 1991) FEMA Public Assistance Project Grants Counties of Barnstable, Bristol, Dukes, Essex, Middlesex, Plymouth, Nantucket, Norfolk TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 9 DISASTER NAME (DATE OF EVENT) TYPE OF ASSISTANCE DECLARED AREAS No-Name Storm (October 1991) (continued) FEMA Individual Household Program Counties of Barnstable, Bristol, Dukes, Essex, Middlesex, Plymouth, Nantucket, Norfolk Hazard Mitigation Grant Program Counties of Barnstable, Bristol, Dukes, Essex, Middlesex, Plymouth, Nantucket, Norfolk, Suffolk (10 projects) December Blizzard (December 1992) FEMA Public Assistance Project Grants Counties of Barnstable, Dukes, Essex, Plymouth, Suffolk Hazard Mitigation Grant Program Counties of Barnstable, Dukes, Essex, Plymouth, Suffolk (7 projects) March Blizzard (March 1993) FEMA Public Assistance Project Grants All 14 Counties January Blizzard (January 1996) FEMA Public Assistance Project Grants All 14 Counties October Flood (October 1996) FEMA Public Assistance Project Grants Counties of Essex, Middlesex, Norfolk, Plymouth, Suffolk FEMA Individual Household Program Counties of Essex, Middlesex, Norfolk, Plymouth, Suffolk Hazard Mitigation Grant Program Counties of Essex, Middlesex, Norfolk, Plymouth, Suffolk (36 projects) 1997 Community Development Block Grant-HUD Counties of Essex, Middlesex, Norfolk, Plymouth, Suffolk June Flood (June 1998) FEMA Individual Household Program Counties of Bristol, Essex, Middlesex, Norfolk, Suffolk, Plymouth, Worcester Hazard Mitigation Grant Program Counties of Bristol, Essex, Middlesex, Norfolk, Suffolk, Plymouth, Worcester (19 projects) (1998) Community Development Block Grant-HUD Counties of Bristol, Essex, Middlesex, Norfolk, Suffolk, Plymouth, Worcester March Flood (March 2001) FEMA Individual Household Program Counties of Bristol, Essex, Middlesex, Norfolk, Suffolk, Plymouth, Worcester Hazard Mitigation Grant Program Counties of Bristol, Essex, Middlesex, Norfolk, Suffolk, Plymouth, Worcester (16 projects) February Snowstorm (Feb 17-18, 2003) FEMA Public Assistance Project Grants All 14 Counties January Blizzard (January 22, 2005) FEMA Public Assistance Project Grants All 14 Counties TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 10 DISASTER NAME (DATE OF EVENT) TYPE OF ASSISTANCE DECLARED AREAS Hurricane Katrina (August 29, 2005) FEMA Public Assistance Project Grants All 14 Counties May Rainstorm/Flood (May 12-23, 2006) Hazard Mitigation Grant Program Statewide April Nor’easter (April 15-27, 2007) Hard Mitigation Grant Program Statewide Flooding (March, 2010) FEMA Public Assistance FEMA Individuals and Households Program SBA Loan Bristol, Essex, Middlesex, Suffolk, Norfolk, Plymouth, Worcester Hazard Mitigation Grant Program Statewide Hurricane Earl (September 2010) FEMA Public Assistance Project Grants Barnstable, Bristol, Dukes, Essex, Middlesex, Nantucket, Norfolk, Plymouth, Suffolk, and Worcester Tropical Storm Irene (August 27-28, 2011) FEMA Public Assistance Statewide Hurricane Sandy (October 27-30, 2012) FEMA Public Assistance Statewide Severe snowstorm and Flooding (February 8-09, 2013 FEMA Public Assistance; Hazard Mitigation Grant Program Statewide Blizzard of 2015 (January 26-28, 2015) FEMA Public Assistance; Hazard Mitigation Grant Program Statewide Severe winter storm and Snowstorm (January 2018) Essex, Middlesex, Norfolk, Suffolk, Worcester Severe winter storm and flooding (March 2018) Barnstable, Bristol, Essex, Nantucket, Norfolk, Plymouth COVID-19 Pandemic (January 2020) Statewide Source: database provided by MEMA Since 2018, there have been five Massachusetts State Declared Disasters that affected Winthrop. Below is a list of them, which includes several winter storms as well as the Covid-19 pandemic. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 11 Table 3. State Disaster Declarations since 2018 Disaster Name Date of Event Declared Areas Massachusetts Severe Winter Storm and Flooding March 2-3, 2018 Statewide Massachusetts Severe Winter Storm and Snowstorm March 13-14, 2018 Statewide Massachusetts Covid-19 Pandemic January 20, 2020 – May 11, 2023 Statewide Massachusetts Severe Winter Storm and Snowstorm January 28-29, 2022 Statewide Massachusetts Hurricane Lee September 15-17, 2023 Statewide Source: FEMA Declared Disasters; OpenFEMA Dataset: Disaster Declarations; and FEMA Declared Disasters. FEMA FUNDED MITIGATION PROJECTS Over the last 20 years the Town of Winthrop has received funding from FEMA for two mitigation projects under the Hazard Mitigation Grant Program. These projects totaled $214,004, with $67,597.50 covered by FEMA grants and $5,000 by local funding. The projects are summarized in Table 4 below. Table 4 FEMA-Funded Mitigation Projects Project Title Scope of Work Total Cost Federal Funding Local Funding Point Shirley Storm Surge Impact Reduction Study The proposed scope of work is for a storm surge impact study reduction study to mitigate flooding in the Point Shirley Area. $20,000.00 $14,210.00 $5,000.00 Flood mitigation Utility Retrofit Project Elevation of utilities above base flood elevation for 20 properties $194,004.00 $53,387.50 $0.00 Source: database provided by MEMA TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 12 COMMUNITY PROFILE The Town of Winthrop is a municipality in Suffolk County, Massachusetts, United States. The population of Winthrop was 19,031 at the 2020 U.S. Census. It is an ocean-side suburban community situated at the north entrance to Boston Harbor and is very close to Logan International Airport. The Town is a peninsula, 1.6 square miles (4.2 km2) in area, connected to Revere by a narrow isthmus and to East Boston by a bridge over the harbor inlet to the Belle Isle Marsh Reservation. Settled in 1630, Winthrop is one of the oldest communities in the United States. It is also one of the smallest and most densely populated municipalities in Massachusetts. Winthrop has a reputation for being a safe and pleasant place to live. Winthrop is a close-knit, family-oriented community where everything is within walking distance. There is a public bus route which travels throughout the Town and connects to the Orient Heights stop on the Blue Line of the MBTA A seasonal ferry provides water transportation to downtown Boston. There are numerous parks and playgrounds, six public beaches, four tennis courts, five athletic fields, a public landing for boats and an indoor skating rink. There is a youth center as well as a senior center which both offer many activities and programs. Winthrop Center offers a multitude of shops as well as small clusters of stores in other sections of the Town. Local retail and commercial areas are shown on Figure 2. There are numerous physicians and dentists in the community as well as a community ambulance service. Public facilities include gas, sewer, water, electricity and cable to the entire Town and trash is collected weekly with provision for recycling. Figure 2 Local Retail and Commercial Areas of Winthrop Source: Winthrop 2030, MAPC TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 13 Additionally, active organizations include the Chamber of Commerce, Rotary, American Legion, Amvets, Little League, Soccer Association, Elks, Sons of Italy, Boy and Girl Scouts, Historical Society, Council on Aging, Winthrop Playmakers, three yacht clubs, and a golf club. Transportation and Connectivity One of the most important features of Winthrop to consider for any hazard mitigation is the town’s location on a peninsula where Boston Harbor meets the Atlantic Ocean. Being surrounded by coastal waters on three sides, Winthrop has very limited transportation connections to the mainland. The Town’s Community Resilience Building report notes that: Access to the Town of Winthrop is primarily along Route 145, Winthrop Parkway or across the Belle Isle Bridge (Main Street). Winthrop Parkway connects the town to Revere along a narrow strip of land and this connection has been closed by the Town of Revere in the past due to storm conditions resulting in unsafe passage. With only two main roadways to access Winthrop, managing this infrastructure is critical for emergency evacuation and response. Or, if evacuation and response is not possible, managing isolation and sheltering in place becomes critical. In addition to road access, a passenger ferry connects Winthrop to downtown Boston. However, during extreme storm events this would not be available to aid in evacuating residents. Figure 3 Belle Isle Bridge and Winthrop Ferry Resilient Winthrop , Stantec/Woods Hole Group Photo: M. Pillsbury Resilient Winthrop also underscores the critical nature of Winthrop’s limited roadway connectivity: With only two roadways to access the Winthrop peninsula, the resilience of transportation infrastructure is particularly important for emergency evacuation and response. Roads play an important role in disaster recovery efforts by providing access to damaged areas for emergency responders and construction equipment. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 14 The Town’s Climate Action Plan also emphasizes the importance of connectivity and evacuation routes: “ Flooding occurs on critical path evacuation routes, including Main Street, Shirley Street, Washington Street and Pleasant Street, creating a public safety issue ” Demographic Characteristics The 2020 population of Winthrop was 19,031 people and there were 8,242 households. (2020 US Census, 2017-21 American Community Survey). The significant demographic characteristics of the Town of Winthrop are summarized in Table 5. Some of these features are important to keep in mind for hazard mitigation as well as emergency preparedness and response in the Town. Table 5. Town of Winthrop Characteristics Population Total population 19,031 Residents under 5 years old 4.4% Residents 65 years old and over 20.2% Race & Ethnicity American Indian and Alaska Native 48 Asian 293 African American 790 White 15,031 Hispanic or Latino 2,533 Other Race 894 Two or More Races 993 Household Income Total Households 8,242 Median Household Income $86,780 Renter occupied housing units 41.1% Languages Speak a language other than English at home Spanish 2230 Other Indo-European languages 2283 Asian and Pacific Island languages 269 Other languages 157 Speaks English less than “very well” 2.6% Residents with a Disability 29.8% Age 65 and over with a disability 6.3% Households in Poverty 12.2% Households with no vehicle 12.5% Households with no internet service 12.8% Sources: US Census, 2020 Decennial Census and American Community Survey (ACS) 5-Year Estimates (2017-2021) TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 15 Environmental Justice Populations There are seven Environmental Justice census block groups in Winthrop designated by the MA Executive Office of Energy and Environmental Affairs. An environmental justice population is a neighborhood where one or more of the following criteria are true: • Median household income is 65 percent or less of the statewide median household income • Minorities make up 40 percent or more of the population • 25 percent or more of households identify as speaking English less than "very well" In Winthrop, four census block groups are designated Environmental Justice based on minority population and three are designated based on median household income. None of the block groups meet the criteria for limited English. See Map 1A in Appendix A. Water Resources Winthrop is located within the Mystic River Watershed and within the Boston Harbor Subbasin. The Mystic River Watershed is a densely populated and very urban watershed with a long history of industrial development and pollution. Water quality issues stem from a variety of sources including stormwater runoff, point source pollution, contaminated sediments in the river due to industrial uses, lack of access to open space as well as invasive species. A large number of community organizations as well as New England EPA and the Mystic River Watershed Association are actively working to improve water quality and access to open space. There are no rivers or streams within the town. The only body of surface water is Lewis Lake. Belle Isle Inlet to the north forms the boundary between Boston and Winthrop. Therefore, the major water quality issue in Winthrop is the health of Boston Harbor and its impact on the cleanliness of the beaches. Lewis Lake receives stormwater runoff from approximately 1/3 of the town. The lake is only a few inches deep because of siltation from run-off. The upper lake is freshwater and the lower lake is brackish water and saltwater. The edge of the lake is very weedy with phragmites. There is a manually operated tidal gate. The lake needs to be dredged or it will eventually fill in and be unable to hold and absorb stormwater runoff. The town is investigating installing a closed drainage pipe in the existing culvert and swale along Veterans Road as well as installation of an automatic tide gate. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 16 SECTION 3: PLANNING PROCESS & PUBLIC PARTICIPATION MAPC employs a planning process based on FEMA’s hazard mitigation planning guidance focusing on local needs and priorities, but maintaining a regional perspective matched to the scale and nature of natural hazard events. Public participation is a central component of this process, providing critical information about the local occurrence of hazards while also serving as a means to build a base of support for hazard mitigation activities. MAPC supports participation by the general public and other plan stakeholders through: • Four meetings and coordination with the Local Hazard Mitigation Team • Two public meetings, advertised through email, webpage content, a flyer, press release to local media, and social media posts, and made available town-wide on Local Access TV, • A project website at: www.mapc.org/resource-library/winthrop-hmp and a dedicated email for public comments, WinthropResilience@mapc.org • Opening a public comment period at the second public meeting, and posting the draft plan to the project website to facilitate public review, • Outreach to neighboring communities, boards and commissions, the local chamber of commerce and businesses, environmental NGO’s, social service providers, and other local or regional stakeholders. PLANNING PROCESS SUMMARY The six-step planning process outlined below and in Figure 4 is based on the guidance provided by FEMA in the Local Multi-Hazard Mitigation Planning Guidance. The process focuses on local problem areas and identifies needed mitigation measures based on where gaps occur in the existing mitigation efforts of the municipality. The planning process allows municipal staff to bring the most recent hazard information into the plan, including new hazard occurrence data, changes to a municipality’s mitigation measur es, and progress made on actions identified in previous plans. Figure 4: Six-Step Planning Process TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 17 1. Map the Hazards – MAPC relies on data from a number of different federal, state, and local sources in order to map the areas with the potential to experience natural hazards. This mapping represents a multi-hazard assessment of the municipality and is used as a set of base maps for the remainder of the planning process. A particularly important source of information is the knowledge drawn from local municipal staff on where natural hazard impacts have occurred, which is collected. These maps can be found in Appendix A. 2. Assess the Risks & Potential Damages – Working with local staff, critical facilities, infrastructure, vulnerable populations, and other features are mapped and contrasted with the hazard data from the first step to identify those that might represent particular vulnerabilities to these hazards. Land use data and development trends are also incorporated into this analysis. In addition, MAPC develops estimates of the potential impacts of certain hazard events on the community. MAPC drew on the following resources to complete the plan: • Town of Winthrop, General Bylaws • Town of Winthrop, Zoning Bylaw • Town of Winthrop, Business District Master Plan, 2017 • Town of Winthrop, Climate Action Plan for Winthrop, 2025 • Town of Winthrop, Municipal Vulnerability Preparedness, 2018 • Town of Winthrop, Stormwater Management Program Plan, 2022 • Town of Winthrop, Open Space and Recreation Plan, 2014 • Town of Winthrop, Resilient Winthrop, Designing Coastal Infrastructure for Climate Change • Town of Winthrop, Winthrop 2030 • Blue Hills Observatory • Environment America Research and Policy Center, When It Rains It Pours – Global Warming and the Increase in Extreme Precipitation, July 2012 • FEMA, Disaster Declarations for States and Counties, 1978-2025 • FEMA, Flood Insurance Study, Suffolk County, 2024 • FEMA Flood Insurance Rate Maps for Suffolk County, MA, 2016 • FEMA, HAZUS-MH, 2023 • FEMA, Local Mitigation Planning Policy Guide, 2025 • Massachusetts Climate Change Assessment, 2022 • Massachusetts Report of the MA Coastal Erosion Commission, 2016 • MA Office of Coastal Zone Management, Sea Level Rise: Understanding and Applying Trends and Future Scenarios for Analysis and Planning, December 2013. • MA Office of Dam Safety, Inventory of Massachusetts Dams • Massachusetts State Hazard Mitigation and Climate Adaptation Plan, 2018, 2023 • Massachusetts State Hazard Mitigation Plan, 2013 • Metropolitan Area Planning Council, Winthrop Climate Resilient Land Use Project • Metropolitan Area Planning Council, GIS Lab, Regional Plans and Data. • New England Seismic Network, Boston College Weston Observatory • NOAA Centers for Environmental Information • Northeast States Emergency Consortium • Tornado History Project TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 18 • US Census, 2020, American Community Survey2017-21 • USDA Forest Service, Wildfire Risk to Communities • USGS, National Water Information System • U.S. Global Change Research Program, Fourth National Climate Assessment, 2018 3. Review Existing Mitigation – Municipalities in the Boston Metropolitan Region have an active history in hazard mitigation as most have adopted flood plain zoning districts, wetlands protection programs, and other measures as well as enforcing the State building code, which has strong provisions related to hazard resistant building requirements. All current municipal mitigation measures are documented in the plan. 4. Develop Mitigation Strategies – MAPC works with the local municipal staff to identify new mitigation measures, utilizing information gathered from the hazard identification, vulnerability assessments, and the community’s existing mitigation efforts to dete rmine where additional work is necessary to reduce the potential damages from hazard events. Additional information on the development of hazard mitigation strategies can be found in Chapter 7. 5. Plan Approval & Adoption – Once a final draft of the plan is complete it is sent to MEMA for the state level review and, following that, to FEMA for approval. Typically, once FEMA has approved the plan the agency issues a conditional approval (Approval Pending Adoption), with the condition being adoption of the plan by the municipality. More information on plan adoption can be found in Chapter IX and documentation of plan adoption can be found in Appendix E. 6. Implement & Update the Plan – Implementation is the final and most important part of any planning process. Hazard Mitigation Plans must also be updated on a five-year basis making preparation for the next plan update an important on-going activity. Chapter IX includes more detailed information on plan implementation. THE LOCAL HAZARD MITIGATION PLANNING TEAM MAPC worked with the municipal leadership to convene and facilitate a local Hazard Mitigation Planning Team for Winthrop. MAPC briefed the municipality as to the desired composition of that team as well as the need for outreach to stakeholders such as the business community, civic organizations and citizens. The team was composed of staff and local officials from a number of different Town Departments and representatives of the North Suffolk Office of Resilience and Sustainability. The Winthrop Hazard Mitigation Planning Team membership can be found in Table 6 below. The Hazard Mitigation Team is central to the planning process as it is the primary body tasked with developing a mitigation strategy for the community. The local team was tasked with working with MAPC to set plan goals, provide information on the hazards that impact the Town, existing mitigation measures, and help to develop new mitigation measures for this plan update. The team met on the following dates focusing on various aspects of developing the updated plan: TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 19 July 16, 2024 Identify and map Critical Facilities, Local Hazard Areas, and Development October 28, 2024 Review/update Existing Mitigation Measures and Hazard Mitigation Goals March 26, 2025 Review the status of recommended mitigation measures from the 2015 plan April 15, 2025 Review and finalize the mitigation strategy for the 2025 updated plan Table 6: Membership of the Winthrop Hazard Mitigation Team Name Position Anthony Marino Town Manager Cheryl McCormick Assistant Town Manager John Goodwin Police Chief Scott Wiley Fire Chief Steven Calla Director of Public Works Department Stephen Calandra Deputy Fire Chief Al Legee Building Commissioner Chris Boyce Planning Board Chair D. Baird Board of Appeals Chair Kim Dimes Conservation Commission Chair Barbara Evangelista Planning Board/Board of Appeals Clerk Laurisa Wojcik Executive Assistant to Town Manager Steve Rogers Police Dept. Ferruccio Romeo Deputy Chief of Policed Meredith Hurley Director, Winthrop Public Health and Clinical Services Homeyer, Kristen Resilience Manager, N. Suffolk Resilience & Sustainability Abderezak Azib Resilience Manager, N. Suffolk Resilience & Sustainability Under Massachusetts Home Rule law and tradition, the Town of Winthrop has primary responsibility for regulating development in town. The Winthrop Planning Board and the Conservation Commission are the primary local agencies responsible for regulating development in town. The Board of Appeals and the Building Commissioner also have key responsibilities for development in Winthrop. Their feedback on development of the plan was assured through the participation of the Chairmen of the Planning Board, Conservation Commission, and Board of Appeals as well as the Building Commissioner on the local Hazard Mitigation Team.. In addition, MAPC, as the State designated regional planning agency for Winthrop, works with all agencies that regulate development and infrastructure in the region, including the l municipal entities and state agencies, such as MassDOT, the Massachusetts Dept. of Conservation and Recreation and the Massachusetts Water Resources Authority. PUBLIC MEETINGS Public participation in the hazard mitigation planning process is important, both for plan development and for later implementation of the plan. Residents, business owners, and other community members can be a good source for information on the historical and potential impacts of natural hazard events and particular vulnerabilities the community may face from these hazards. Their participation in the planning process also builds understanding of the concept of TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 20 hazard mitigation, potentially creating support for mitigation actions taken in the future to implement the plan. Public participation in this planning process is important for improving awareness of the potential impacts of natural hazards and to build support for the actions the Town takes to mitigate them. The public had an opportunity to provide input to the hazard mitigation planning process at two public meetings, one during the planning process and one after a complete draft plan is available for review. The Winthrop Town Council hosted the public meetings, the first on May 20, 2025, and the second on October xx, 2025. The Town Council meetings were publicized according to Massachusetts Open Meeting Law and were televised locally and available on videos on You Tube. Both meetings were publicized on the To wn’s website and social media, and direct outreach by email. A Media Advisory was also sent to the local press. The first meeting featured an overview of the hazard mitigation planning process, and summary of the plan and mitigation actions. The draft plan was presented at the second public meeting. The plan was posted online on the project web page for public access to review and comment on the plan. and a dedicated project email, WinthropResilience@mapc.org , was set up to receive public comments and questions. Key town stakeholders and neighboring communities were notified and invited to review the draft plan and submit comments. See Documentation of Public Meetings in Appendix C. LOCAL STAKEHOLDER INVOLVEMENT The Town reached out to local stakeholders that might have an interest in the Hazard Mitigation Plan including neighboring communities, agencies, businesses, nonprofits, and other interested parties. Notice was sent to the following organizations and neighboring municipalities inviting them to review the Hazard Mitigation Plan and submit comments to the Town: Table 7: Winthrop Community Stakeholders Cat Pedmonti Mystic River Watershed Association Cindy Baxter Friends of Belle Isle Marsh John DaRos Winthrop Town Councilor, Precinct 6 Town of Winthrop Winthrop Climate Commission Town of Winthrop Citizens Advisory Committee on Climate Town of Winthrop Council on Aging City Clerk City of Boston City Clerk City of Revere The draft plan was posted online for public review, The Town received [TBD] comments, which are included in Appendix C. CONTINUING PUBLIC PARTICIPATION Following the adoption of the plan update, the planning team will continue to provide residents, businesses, and other stakeholders with the opportunity to learn about the hazard mitigation planning process and to contribute information that will update the town’s understanding of local TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 21 hazards. As the review of the plan is conducted by the Hazard Mitigation Team, these will be placed on the Town’s web site, and any meetings of the Hazard Mitigation Team will be publicly noticed in accordance with town and state open meeting laws. PLANNING TIMELINE PLAN UPDATE PROCESS 2024-25 July 16, 2024 1 st Meeting of the Winthrop Hazard Mitigation Team October 28, 2024 2 nd Meeting of the Winthrop Hazard Mitigation Team March 26, 2025 3 rd Meeting of the Winthrop Hazard Mitigation Team April 15, 2025 4 th Meeting of the Winthrop Hazard Mitigation Team May 20, 2025 Public Meeting #1 hosted by the Town Council Oct. xx, 2025 Public Meeting #2 hosted by the Town Council PLAN IMPLEMENTATION MILESTONES 2026-30 After this plan update is approved by FEMA for a five-year period, the Town should take note of the following milestones for the ongoing implementation, review, and updating of this plan: 2028 Conduct Mid-Term Plan Survey on Progress 2029 Seek FEMA grant to prepare next plan update 2030 Begin process to update the plan 2031 Submit Draft 2031 Plan Update to MEMA and FEMA 2031 FEMA approval of 2030 Plan Update TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 22 SECTION 4: RISK ASSESSMENT The risk assessment analyzes the potential natural hazards that could occur within the Town as well as the relationship between those hazards and current land uses, potential future development, and critical infrastructure. This section also includes a vulnerability assessment that estimates the potential damages that could result from certain large-scale natural hazard events. In order to update Marlborough’s risk assessment, MAPC gathered the most recently available hazard and land use data and met with the Local Team to identify changes in local hazard areas and development trends. MAPC also used FEMA’s damage estimation software, Hazards US (HAZUS). The projected impacts of our warming climate on natural hazards are integrated throughout this risk assessment. Key impacts include rising temperatures, which in turn affect precipitation patterns and extreme weather. Analysis of these impacts included in this plan aligned closely with the data and assessment presented in Massachusetts’ State Hazard Mitigation and Climate Adaptation Plan (SHMCAP) and the Massachusetts’ 2022 Climate Change Assessment. CLIMATE CHANGE OBSERVATIONS AND PROJECTIONS Climate change observations come from a variety of data sources that have measured and recorded changes in recent decades and centuries. Climate change projections, however, predict future climate impacts and, by their nature, cannot be observed or measured. As a result of the inherent uncertainty in predicting future conditions, climate projections are generally expressed as a range of possible impacts. TEMPERATURE Our climate has always been regulated by gases, including carbon dioxide, methane, and nitrous oxide, which blanket the earth. These gases trap heat that would otherwise be reflected out to space; without them our planet would be too cold to support life. We refer to these gases as “greenhouse gases” (GHGs) for their heat trapping capacity. The combustion of fossil fuels, our primary energy source in the age of industrialization, releases GHGs into the atmosphere. In the past century, human activity associated with industrialization has contributed to a growing concentration of GHGs in our atmosphere. Records from the Blue Hill Observatory in Milton, MA show that average temperatures (30-year mean) have risen approximately 3 degrees (F) in the almost 200 years since record keeping began in 1831. See Figure 5 below for more information. “Global climate is changing rapidly compared to the pace of natural variations in climate that have occurred throughout Earth’s history. Global average temperature has increased by about 1.8°F from 1901 to 2016, and observational evidence does not support any credible natural explanations for this amount of warming; instead, the evidence consistently points to human activities, especially emissions of greenhouse or heat- trapping gases, as the dominant cause.” Fourth National Climate Assessment, 2018 (Chapter 2-1) TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 23 Figure 5: Observed Increase in Temperature Climate projections include an increase in average temperature and in the number of extreme heat days. Extreme cold days are projected to decrease in number. By 2030, the summer mean temperature could increase by 3.6°F from the historical period (1950-2013). By 2070, there could be 58 fewer days below freezing, which could lead to an increase in ticks. By mid-century, the State anticipates about 25 more days per year where the temperature exceeds 90°F for inland areas, and about 19 more days above 90°F for coastal areas (Commonwealth of Massachusetts, 2022). Figure 6: Change in the Annual Number of Days Over 90 F Compared to Today Sources: 2022 MA Climate Change Assessment and Stochastic Weather Generator TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 24 These changes could result in Massachusetts summers feeling like a more southern state, as described in the infographic in Figure 7 from the State’s 2022 Climate Change Assessment. Figure 7: Change in Average Summertime Temperatures for Massachusetts Source: 2022 MA Climate Change Assessment PRECIPITATION PATTERNS Annual precipitation in Massachusetts has increased by approximately 10% in the fifty-year period from 1960 to 2010 (MA EEA, 2011). Moreover, there has been a significant increase in the frequency and intensity of large rain events. For the Northeast US, according to the Fourth National Climate Assessment 2018, in the past sixty years there has been a 55% increase in the amount of annual precipitation that falls in the top 1% of storm events, as shown in Figure 8 below (US Global Change Research Program, 2018). Changes in precipitation are fueled by warming temperatures which increase evaporation and, therefore, the amount of water vapor in the air. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 25 Figure 8: Observed Change in Total Annual Precipitation in the Heaviest 1% Events Source: Fourth National Climate Assessment, 2018 Numbers circled in black indicate % change. Massachusetts’ 2022 Climate Change Assessment anticipates that most parts of the State will see a future increase in annual total precipitation of less than 8% per year. Most of these increases are anticipated during the winter months (see Figure 9 below). Additionally, t he historic 10% annual chance daily rainfall event (2.8- 4.0” of rain) could occur four times more frequently by 2090 (Commonwealth of Massachusetts, 2022). TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 26 Figure 9: Change in Annual and Seasonal Precipitation in 2070 Compared to Today Source: 2022 MA Climate Change Assessment. The current climate is the 1986-2005 era, the projection for 2070 is for a 20-year era centered on 2070. Maps show LOCA downscaled GCM projections at the 50th percentile across 20 LOCA GCMs that overlap with the GCMs used in the Stochastic Weather Generator. Despite overall increasing precipitation, more frequent and significant summer droughts are also a projected consequence of climate change. This is due to projections that precipitation will increase in winter and spring and decrease slightly in the summer and, as a result of earlier snow melt, and higher temperatures that will reduce soil moisture. Massachusetts’ 2022 Climate Change Assessment anticipates that these changes will vary by region. The North and South Shore region where Winthrop is located may experience slightly more consecutive dry days, and significantly more days without rain per year, by 2090 (Commonwealth of Massachusetts, 2022). See Figure 10 below for more information. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 27 Figure 10: Consecutive dry day events (number of multiple-dry-day events per year) Source: 2022 MA Climate Change Assessment. The Town of Winthrop is located in the North & South Shores region. SEA LEVEL RISE High-level information on sea level rise is discussed here as the town as well as the regional economy of the Boston Metro area may be impacted by sea level rise in the future. Warming temperatures contribute to sea level rise in three ways. First, warm water expands to take up more space. Second, rising temperatures are melting land-based ice which enters the oceans as melt water. A third, quite minor, contributor to sea level rise in New England is not related to climate change. New England is still experiencing a small amount of land subsidence (drop in elevation) in response to the last glacial period. NOAA’s records from the Boston Tide Station show nearly one foot of sea level rise over the past century. See Figure 11 below for more information. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 28 Figure 11: Observed Increase in Sea Level Rise Source: NOAA The sea level rise information in Massachusetts’ 2022 Climate Change Assessment considers sea - level changes, land-level changes, and other regional facts that can impact the rate of change. The report includes the following approximate sea level rise projections for the State: • Northern Massachusetts: 21 inches by 2050, and 43 inches by 2070 • Southern Massachusetts: 23 inches by 2050 and 45 inches by 2070 The 2022 Climate Change Assessment also quantified the developed land area flooded for events including: • the 20-year (5% annual probability) • 100-year (1% probability) • 1000-year (0.1% probability) events This approach found that the area flooded by the current 1000-year event is comparable to the area of a 20-year event by 2050. Even more areas could be impacted by the annual probability event by 2070. See Figure 12 below for more information. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 29 Figure 12: Total Flooded Area of the Commonwealth for Selected Events Source: 2022 MA Climate Change Assessment CLIMATE CHANGE AND HAZARD MITIGATION Following the outline of the Massachusetts State Hazard Mitigation and Climate Adaptation Plan (SHMCAP), this local hazard mitigation plan organizes consideration of natural hazards based on their relationship to projected climate changes. Table 8 below, which is originally from the 2018 SHMCAP, summarizes the natural hazards reviewed in this plan, climate interactions, and expected impacts. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 30 Table 8: Climate Change & Natural Hazards Primary Climate Change Interaction Natural Hazard Other Climate Change Interactions Representative Climate Change Impacts Changes in Precipitation Inland Flooding Extreme Weather Flash flooding, urban flooding, drainage system impacts (natural and human- made), lack of groundwater recharge, impacts to drinking water supply, public health impacts from mold and worsened indoor air quality, vector-borne diseases from stagnant water, increased potential for loss of life, episodic drought, changes in snow-rain ratios, changes in extent and duration of snow cover, degradation of stream channels and wetland Drought Rising Temperatures, Extreme Weather Landslide Rising Temperatures, Extreme Weather Sea Level Rise Coastal Flooding Extreme Weather Increase in tidal and coastal floods, storm surge, coastal erosion, marsh migration, inundation of coastal and marine ecosystems, loss of wetlands Coastal Erosion Extreme Precipitation Tsunami Rising Temperatures Rising Temperatures Average/Extreme Temperatures N/A Shifting in seasons (longer summer, early spring, including earlier timing of spring peak flow), increase in length of growing season, increase of invasive species, increase in vector-borne illnesses (West Nile, Zika, EEE), ecosystem stress, energy brownouts from higher energy demands, more intense heat waves, public health impacts from high heat exposure and poor outdoor air quality, increased potential for loss of life, drying of streams and wetlands, eutrophication of lakes and ponds Wildfires Changes in Precipitation Invasive Species Changes in Precipitation, Extreme Weather Extreme Weather Hurricanes/Tropical Storms Rising Temperatures, Changes in Precipitation Increase in frequency and intensity of extreme weather events, resulting in greater damage to natural resources, property, and infrastructure, as well as increased potential for loss of life Severe Winter Storm / Nor’easter Tornadoes Other Severe Weather (Strong Wind & Thunderstorms) TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 31 UPDATE PROCESS In order to update Winthrop ’s risk assessment, MAPC gathered the most recently available hazard and land use data from federal and state sources and met with Town ’s Hazard Mitigation Team to identify changes in local hazard areas and development trends. The local Team also reviewed critical infrastructure with MAPC staff in order to create an up-to-date inventory and accompanying GIS map. MAPC also used the most recently available version of FEMA’s HAZUS- MH program (described below) to assessed the potential impacts of Hurricanes, Tornadoes, and Flooding. OVERVIEW OF HAZARDS AND IMPACTS The risk assessment analyzes the potential natural hazards that could occur within the Town of Winthrop as well as the relationship between those hazards and current land uses, potential future development, and critical infrastructure. This updated plan also recognizes that climate change is projected to have significant impacts on many natural hazards in Winthrop. The Resilient MA Plan (2023), the Massachusetts Climate Change Assessment (2022), and the SHMCAP (2018) are key planning documents that examine natural hazards and climate trends that have the potential to impact the Commonwealth. The 2013 State HMP set the stage by defining considerations such as frequency and severity and summarizing the frequency and severity of hazards of greatest concern. The 2018 SHMCAP used similar definitions for hazard considerations and expanded on this research by including additional climate projections. Because the 2013 State HMP includes definitions that were not specified in the SHMCAP, both resources are referred to in this report. Table 9 below summarizes the hazard risks for Winthrop, with reference to the hazards in Massachusetts. This evaluation takes into account the frequency and severity of each hazard for Massachusetts and Winthrop, based on available data, including: • State-level data, including the Resilient MA Plan, the 2022 Climate Change Assessment, and 2018 SHMCAP. • County-level data from NOAA’s National Climatic Data Center and Storm Events Database for Suffolk County (where Winthrop is located) • Local-level information including input from the Local Team, the hazard mapping included in Appendix A, and the HAZUS results. The statewide hazard risk assessment is based on the definitions for hazard frequency and severity listed below. The statewide assessment was modified to reflect local conditions in Winthrop using the same criteria. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 32 Table 9 - Hazard Risks Summary Hazard Frequency Severity Massachusetts Winthrop Massachusetts Winthrop Flooding from Precipitation Very High High Serious Serious Dam failures Very Low N/A Extensive N/A Coastal Erosion Very High Very High Serious-Extensive Extensive Coastal Flooding Very High Very High Serious-Extensive Extensive Tsunami Very Low Very Low Extensive-Catastrophic Extensive- Catastrophic Hurricane/Tropical Storm Medium Medium Serious - Catastrophic Extensive Tornadoes High Low Serious - Extensive Serious Other Severe Weather (Thunderstorms/Hail) Very High High Minor - Extensive Minor-Serious Severe Winter/ Nor’easter /Blizzards High High Minor - Extensive Extensive Winter-Ice Storms Medium Medium Minor - Extensive Minor Earthquakes Medium Medium Serious - Catastrophic Serious Landslides High Very Low Minor - Extensive Minor Wildfire/Brushfires Very High Medium Minor - Extensive Minor Extreme Temperatures Very High High Minor -Serious Minor Drought Medium Medium Minor - Serious Minor Sources: Resilient MA Plan (Frequency), State Hazard Mitigation Plan 2013 (Severity), HAZUS, Local information. Definitions of Hazard Frequency and Severity Frequency Very low: Very unlikely; minimal examples of historical occurrences. Low: Likely to occur at least once by the end of the century; some examples of historical occurrences; anticipated every 100 years. Medium: Likely to occur at least once every 50 years (two or more occurrences in the next century) High : Almost certain to occur at least once a year. Very High: Almost certain to occur multiple times a year. Severity Minor : Limited and scattered property damage; limited damage to public infrastructure and essential services not interrupted; limited injuries or fatalities. Serious: Scattered major property damage; some minor infrastructure damage; essential services are briefly interrupted; some injuries and/or fatalities. Extensive: Widespread major property damage; major public infrastructure damage (up to several days for repairs); essential services are interrupted from several hours to several days; many injuries and/or fatalities. Catastrophic: Property and public infrastructure destroyed; essential services stopped; numerous injuries and fatalities. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 33 Not all hazards listed in the Resilient MA Plan affect the Town of Winthrop The Town considered changing groundwater levels but did not designate that as a hazard in Winthrop. USGS groundwater monitoring records show no trend in lower groundwater levels over the last 50 years. Further, the Town does not use groundwater wells as a source of water supply, as a member of the MWRA regional water system. Landslides, while possible, have never occurred and the town is ranked “Low Susceptibility” for landslides. Current land use regulations govern stabilization of slopes, and the Town did not conclude that further mitigation for landslide is warranted. FLOODING HAZARDS FLOODING FROM PRECIPITATION AND COASTAL FLOODING Flooding was the most prevalent natural hazard identified by local officials in Winthrop. Given the Town’ s location on Boston Harbor, the Town is subject to two kinds of flooding; coastal flooding, where wind, tide, and storm surges lead to flooding in low-lying areas along the shore and tidal waterways, and flooding from precipitation, or stormwater flooding, where the rate of precipitation or amount of stormwater runoff overwhelms the capacity of natural and structured drainage systems to convey water causing it to overflow the system. These two types of flooding are often combined as inland flooding is prevented from draining by the push of wind and tide driven water. FLOODING FROM PRECIPITATION Flooding is generally caused by severe rainstorms, hurricanes, nor’easters, and thunderstorms. Severe rainstorms can occur year-round. Hurricanes are most common in the summer and early fall while Nor’easters are most common in winter. Spring snowmelt may exacerbate flooding during storm events. Climate change has the potential to exacerbate these issues over time due to increasing extreme rainfall events. Increase in average annual rainfall may also lead to more incidents of basement flooding caused by high seasonal groundwater levels. Regionally Significant Floods There have been a number of major floods that have affected the Metro Boston region over the last fifty years. Significant historic flood events have included those listed below (NOAA, 2024) • The Blizzard of 1978 • January 1979 • April 1987 • October 1991 • December 1992 • October 1996 • June 1998 • March 2001 • April 2004 • May 2006 • April 2007 • March 2010 • December 2010 • March 2013 • January 2018 • March 2018 • June 2020 TOWN OF ESSEX HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 33 Most severe flooding event within last 15 years The most severe flooding event in Eastern Massachusetts in the last 15 years occurred during March 2010, when a total of 17.7 inches of rainfall was recorded by the Blue Hills Observatory from three storms over 19 days from March 13 to 31. The weather pattern that consisted of early springtime prevailing westerly winds that moved three successive storms, combined with tropical moisture from the Gulf of Mexico, across New England. Torrential rainfall caused March 2010 to be the wettest month on record. The March 2010 rainstorms fit the profile of a type of severe precipitation event expected to increase in frequency as the climate warms. That is, significant precipitation, falling in late winter as rain rather than snow, on frozen ground, and while vegetation is still dormant. One indication of the extent of flooding is the gage height at the nearest USGS streamflow gauging station, which is on the Saugus River in Saugus, MA. The USGS gage height, shown in Figure 13, reached 6.41 feet on March 15, 2010 during the first storm, and rose again to 6.21 feet on March 31, 2010 during the second storm. Normal gage height in March is about 3 feet. Figure 13- Saugus River Gage Heights, March-April 2010 Source, US Geological Service, National Water Information System Previous Inland/Stormwater Flooding Events The best available local data on previous inland flooding events in Winthrop is from NOAA’s National Centers for Environmental Information Storm Events Database, which provides county- level records of natural hazards (see Table 10). Suffolk County, which includes the Town of Winthrop, experienced 29 flood events from 2005 – 2025. There were no deaths or injuries TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 34 reported and the total reported property damage in the county was $10.945 million dollars. Damages from the major flooding during the storms of March 2010 totaled $10.7 million. Notably, that represents 98% of total flood damage for Suffolk County over the entire 20-year period from 2005 to 2025. The 2010 storms were a federally declared disaster, making federal assistance available to residents who did not carry flood insurance. That resulted in 25 claims in the Town of Winthrop, totaling $32,447. The HAZUS analysis estimates flooding damages in Winthrop from a 100-year storm at $236.8 million and $334.7 from a 500-year storm (Table 46). Table 10 Suffolk County Flood Events, 2005 – 2025 Date Deaths Injuries Property Damage 5/13/2006 0 0 0 10/28/2006 0 0 $8,000 /13/2008 0 0 $5,000 3/14/2010 0 0 $10,700,000 8/25/2010 0 0 0 10/29/2012 0 0 $15,000 6/7/2013 0 0 0 9/1/2013 0 0 $5,000 10/23/2014 0 0 $30,000 7/23/2016 0 0 0 7/12/2017 0 0 0 7/18/2017 0 0 0 8/2/2017 0 0 0 9/14/2017 0 0 $25,000 9/30/2017 0 0 $90,000 10/30/2017 0 0 0 5/15/2018 0 0 0 6/25/2018 0 0 0 8/12/2018 0 0 $10,000 9/25/2018 0 0 $3,000 11/3/2018 0 0 0 6/29/2019 0 0 $20,00 7/06/2019 0 0 0 7/31/2019 0 0 $4,000 8/7/2019 0 0 0 6/28/2020 0 0 0 7/9/2021 0 0 0 1/23/2023 0 0 0 7/16/2023 0 0 0 TOTAL 0 0 $10,945,000 Source: NOAA, National Centers for Environmental Information TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 35 Probability of Future Events Flooding in Winthrop is a high frequency event as defined by the Massachusetts State Hazard Mitigation Plan. This hazard is almost certain to occur at least once a year. Inland Flooding and Climate Change Eastern Massachusetts average annual precipitation is 42 inches. While total annual precipitation has not changed significantly, according to the report When It Rains It Pours – Global Warming and the Increase in Extreme Precipitation from 1948 to 2011, intense rainstorms and snowstorms have become more frequent and more severe over the last half century in the northeastern United States . Extreme downpours are now happening 30 percent more nationwide than in 1948 (see Figure 14). Figure 14 Changes in Frequency of Extreme Downpours, 1948 – 2011 Source: When It Rains It Pours – Global Warming and the Increase in Extreme Precipitation, Environment America Research and Policy Center, July 2012 Not only are these intense storm events more frequent, they are also more severe; the largest annual storms now produce 10 percent more precipitation, on average, than in 1948. In particular, the report finds that New England has experienced the greatest change with intense rain and snowstorms occurring 85 percent more often than in 1948. Data from the 2022 MA Climate Change Assessment related to changes in precipitation patterns is included in an earlier section of this chapter. Those projections suggest that future rain events will be increasingly intense and lengthy, which could lead to increased inland and stormwater flooding. Precipitation frequency estimates, which are used to derive stormwater design standards, were published in 196l by the U.S. Commerce Department in a document known as TP-40 (Technical Paper 40). The 10-year, 24-hour storm for eastern Massachusetts was calculated as a 4.5-inch TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 36 event. Recently the National Oceanic and Atmospheric Administration published updated estimates (NOAA Atlas 14), which increased this design storm by 0.6 inches to 5.14 inches for eastern Massachusetts. Communities should consider future rainfall rates when designing infrastructure. For example, communities could consider using NOAA Atlas 14 rainfall rates with an additional allowance to account for projected rainfall during the life of projects permitted today when sizing stormwater infrastructure. DEP takes a similar approach to describe current (not future) rainfall rates, called “NOAA14+”. Mystic River Watershed Association (MyRWA) communities propose “NOAA14++”, which they say reflects 2070 projections. The NOAA 14+ number is calculated by multiplying the NOAA 14 precipitation frequency estimate upper confidence interval by 0.9 (i.e., current but extreme precipitation events reflect 90% of upper confidence intervals). The NOAA 14++ number is the upper confidence interval. A comparison of these numbers is summarized in Table 11 below (NOAA, 2023) . Table 11: Rainfall rates for the 10-year 24-hour storm NOAA 14 NOAA 14+ NOAA 14++ 5.27 inches 5.90 inches 6.56 inches NOAA, 2023 The 2022 MA Climate Change Assessment also highlights the following flooding climate impacts: • By 2050, the 1 percent annual chance river flood could be two times more likely to occur • By 2090, the historical 10 percent annual chance daily rainfall event (2.8 to 4 inches) could occur four times more frequently • Damage could occur to buildings from heavy rainfall and overwhelmed drainage systems • Damage could occur to transit service due to flooding • There could be a reduction in the availability of affordably priced housing from direct damage including from flooding (Commonwealth of Massachusetts, 2022) COASTAL FLOODING Flooding and coastal storm surges are the primary coastal hazards that lead to the loss of lives or damage to property and infrastructure in developed coastal areas. Coastal flooding is associated with severe coastal storms such as Nor’easters and hurricanes which , through the combination of winds and tides, lead to the inundation of low-lying land areas and damage or overtopping of seawalls and other coastal infrastructure. Coastal flooding can also be associated with routine tidal flooding “King Tides,” or higher astronomic tides. Coastal storms are an intricate combination of events that impact a coastal area. Although most common in the fall and winter seasons, a coastal storm can occur any time of the year and at varying levels of severity. One of the greatest threats from a coastal storm is flooding due to storm surge. This is the inundation of land areas along the coastal and estuarine shoreline by seawaters over and above normal tidal action. Coastal flooding can also be associated with TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 37 routine tidal flooding “King Tides,” or higher astronomic tides. Also, the high tide and storm surge can limit the ability of stormwater to drain from inland waterways. Previous Coastal Flooding Events The best available local data for previous coastal flooding occurrences is provided by the NOAA National Centers for Environmental Information. Suffolk County, which includes the Town of Winthrop, experienced 37 coastal flood events from 2005 through 2025 (see Table 12). No deaths or injuries were reported and the total reported property damage in the county was $39 million dollars. Table 12 – Suffolk County Coastal Flood/Storm Surges, 2005-2025 Date Type Deaths Injuries Property Damage 1/23/2005 Storm Surge 0 0 $100K 5/24/2005 Storm Surge 0 0 $15K 5/25/2005 Storm Surge 0 0 $10K 1/31/2006 Coastal Flood 0 0 $10K 2/12/2006 Storm Surge 0 0 $15K 4/15/2007 Coastal Flood 0 0 $5K 4/16/2007 Coastal Flood 0 0 $5K 4/17/2007 Coastal Flood 0 0 $10K 10/18/2009 Coastal Flood 0 0 0 1/2/2010 Coastal Flood 0 0 0 3/14/2010 Coastal Flood 0 0 0 12/27/2010 Coastal Flood 0 0 $50K 8/27/2011 Storm Surge 0 0 0 11/23/2011 Coastal Flood 0 0 0 06/03/2012 Coastal Flood 0 0 0 06/04/2012 Coastal Flood 0 0 0 10/29/2012 Coastal Flood 0 0 $3.0M 2/9/2013 Coastal Flood 0 0 $30.0M 3/7/2013 Coastal Flood 0 0 00 1/2/2014 Coastal Flood 0 0 0 1/3/2014 Coastal Flood 0 0 0 8/13/2014 Coastal Flood 0 0 0 10/23/2014 Coastal Flood 0 0 0 1/27/2015 Coastal Flood 0 0 0 10/28/2015 Coastal Flood 0 0 0 1/24/2016 Coastal Flood 0 0 0 2/8/2016 Coastal Flood 0 0 0 1/4/2018 Coastal Flood 0 0 $500K 1/30/2018 Coastal Flood 0 0 $20K 3/2/2018 Coastal Flood 0 0 0 10/27/2018 Coastal Flood 0 0 0 11/25/2018 Coastal Flood 0 0 0 1/20/2019 Coastal Flood 0 0 0 10/28/2019 Coastal Flood 0 0 0 4/3/2020 Coastal Flood 0 0 0 4/9/2020 Coastal Flood 0 0 0 9/22/2020 Coastal Flood 0 0 0 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 38 12/17/2020 Coastal Flood 0 0 0 2/2/2021 Coastal Flood 0 0 0 7/23/2021 Coastal Flood 0 0 0 1/17/2022 Coastal Flood 0 0 0 12/23/2022 Coastal Flood 0 0 0 1/23/2023 Coastal Flood 0 0 0 1/10/2024 Coastal Flood 0 0 0 1/13/2024 Coastal Flood 0 0 0 3/10/2024 Coastal Flood 0 0 0 4/4/2024 Coastal Flood 0 0 0 TOTAL 0 0 $39M Source: NOAA, National Centers for Environmental Information According to the 2024 Flood Insurance Study for Suffolk County, for the areas of Winthrop that are impacted by coastal flooding processes, coastal flood hazard analyses were performed by FEMA to provide estimates of coastal Base Flood Elevations (BFE). Coastal BFEs reflect the increase in water levels during a flood event due to extreme tides and storm surge as well as overland wave effects. Overland wave hazards were evaluated by FEMA to determine the combined effects of ground elevation, vegetation, and physical features on overland wave propagation and wave runup. These analyses were performed at representative transects along all shoreline for which waves were expected to be present during the floods of the selected recurrence intervals. Table 13 provides the location, stillwater elevations, and starting wave conditions for each Winthrop transect evaluated for overland wave hazards. The results of these analyses were used to determine elevations for the 1% annual chance flood. Eight of the Suffolk County transects are in Winthrop, as shown in Figure 15; these transects are depicted on the FIRM. Table 15: Coastal Transect Parameters for Winthrop Source: Flood Insurance Study for Suffolk County, 2024 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 39 Figure 15: Suffolk County Shoreline Transect Locations for Winthrop Source: Flood Insurance Study for Suffolk County, 2024 As a peninsula located between Boston Harbor, Belle Isle March, and the Atlantic Ocean, Winthrop has extensive exposure to coastal flooding along most of its shoreline. Measures of the severity of coastal flooding include water level elevation and duration of the event. The extent of flooding in Winthrop is indicated by recorded high water marks documented by the US Geological Survey for the Blizzard of 1978, the highest coastal flood on record. The USGS, in cooperation with the Army Corps of Engineers and the Massachusetts Department of Public Works, inventoried high water marks along the New England coast, including seven locations in the Town of Winthrop. The high water levels for these locations area summarized in table 14. Table 14 High Water Marks in Winthrop, Blizzard of 1978 Site No. Elevation (ft-NGVD29) Description 248 12.45 Lat 42°22'41", long 70058'22", Winthrop, Mass., Winthrop Beach, good wash line on seventh clapboard from ground at 65 Beach Street, halfway between seventh and eighth clapboard. Waves over seawall. 249 7 Lat 42°22'16", long 70°58'12", Winthrop, Mass., Cottage Hill, good drift line 1.8ft above base of chain link fence across street from Hadassah Way and Temple Tifreth Israel. Waves over seawall. 250 12.67 Lat 42°21'33", long 70°58'16", Winthrop, Mass., Point Shirley, good to fair debris line 1.8ft above sidewalk on chain link fence at 965 Bayview on corner. Waves over seawall. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 40 251 11.04 Lot 42°21'26", long 70°58'16", Point Shirley, Mass., Boston Harbor, right side" of garage, brick ranch, at 25 Maryland Avenue. High-water-mark description and elevation furnished by the Massachusetts Department of Public Works. 252 11.1 Lat 42°21'27", long 70°58'20", Point Shirley, Mass., Boston Harbor, foundation and mail box at 80 Otis Street. High-water- mark description and elevation furnished by the Massachusetts Department of Public Works. 253 11.09 Lat 42021'27", long 70°58'20", Point Shirley, Mass., Boston Harbor, mail box near driveway of 82 Otis Street. High-water- mark description and elevation furnished by the Massachusetts Department of Public Works. 254 10.38 Lat 42°22'06", long 70°58'20", Cottage Hill, Mass., Crystal Cove, debris line at lower locker deck of Winthrop Yacht Club, 649 Shirley Street. High-water-mark description and elevation furnished by the Massachusetts Department of Public Works. Source: Coastal Flood of Feb. 7, 1978 in ME, MA & NH, Russell A Gadoury, USGS Water Resources Investigations 79-61 Probability of Future Occurrence Based on the record of previous occurrences coastal flooding events in Winthrop are a high frequency event as defined by the Resilient MA Plan. This hazard is almost certain to occur at least once a year. Coastal Flooding and Climate Change Of all the impacts of climate change, Winthrop is most susceptible to the impacts of sea level rise, as it will magnify the flooding associated with coastal storms. As shown by records from the Boston Tide Station (see Figure 11) seas have risen the equivalent of 11 inches over 100 years, based on monitoring data from 1921. The Massachusetts Office of Coastal Zone Management (CZM) adjusted global predictions for future sea level rise, taking into account local subsidence (see Figure 16). The range of projections for the future is quite wide, particularly approaching the end of this century. The High scenario includes ocean warming and a calculation of maximum glacier and ice sheet melt. The Intermediate High scenario averages higher predictions but includes lesser ice sheet melting. The Intermediate Low considers lower sea level rise scenarios and limited ice melt. The Historic Trend reflects a continuation of the current rate of sea level rise. The CZM estimate for the Boston Harbor does not take into account more recent research that suggests the Boston Harbor is included in a region that may experience greater than average sea level rise. CZM cautions that the Historic and Intermediate Low scenarios may “considerably underestimate actual sea level rise”, particularly for time horizons beyond 25 years. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 41 Figure 16 Projected Sea Level Rise for Greater Boston Harbor Source: Sea Level Rise: Understanding and Applying Trends and Future Scenarios for Analysis and Planning, Massachusetts Office of Coastal Zone Management, December 2013. Fueled by the warming climate, coastal flooding will become more frequent and severe due to the combination of sea level rise and more frequent and intense storms. Projections of future sea level rise identify locations that will be subject to flooding in future years. While those areas do expand with increasing sea level, the more significant impact will be frequent and deeper flooding in the locations already subject to coastal flooding. Figure 17 shows projections of flood inundation area in Winthrop related to three future sea level rise scenarios developed for the Massachusetts Coastal Flood Risk Model (MC-FRM) by the Wood Hole Group. The map shows the extent of flood inundation for a 1% annual chance storm for projected sea level rise scenarios of 1.2 feet, 2.4 feet, and 4.2 feet. These scenarios are approximately equivalent to the levels of sea level rise projected for the years 2030, 2050, and 2070, respectively. This map is also included in the hazard map series in Appendix A. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 42 Figure 17: Areas Inundated in Future Sea Level Rise Scenarios Source: Woods Hole Group, Massachusetts Coastal Flood Risk Model TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 43 INLAND AND COASTAL FLOOD HAZARD AREAS IN WINTHROP Information on potential flood hazard areas was taken from two sources. The first was the National Flood Insurance Rate Maps. The FIRM flood zones are shown on Map 3 in Appendix A and their definitions are listed below. The most significant areas of Zone A (1% annual chance of flooding) are across the Belle Isle Marsh and Winthrop’s shoreline, both facing the Atlantic Ocean and Boston Harbor, with the most extensive areas on the ocean side. There are no flood hazard areas in Winthrop associated with rivers and streams; all of the town’s exposure to flooding is from coastal sources. Locally Identified Areas of Inland and Coastal Flooding The second source of information on local flooding was the Winthrop Hazard Mitigation Team. The locally identified areas of flooding described below were identified by town staff as areas where flooding occurs. The 15 locally identified areas of flood hazard described below and shown on Map 8 in Appendix A were identified by the Winthrop Hazard Mitigation Team as areas where flooding is known to occur. Sites 12 through 15 were added to the plan for this 2025 update. These areas do not necessarily coincide with the flood zones from the FIRM maps. They may be areas that flood due to inadequate drainage systems or other local conditions rather than location within a flood zone, or areas subject to coastal flooding in part due to infrastructure that may require upgrading. The site numbers correspond to the numbers on Map 8, “Hazard Areas”. The numbers do not reflect priority order. Flood Insurance Rate Map Zone Definitions Zone A (1% annual chance): Zone A is the flood insurance rate zone that corresponds to the 100-year floodplains that are determined in the Flood Insurance Study (FIS) by approximate methods. Because detailed hydraulic analyses are not performed for such areas, no BFEs (base flood elevations) or depths are shown within this zone. Mandatory flood insurance purchase requirements apply. Zone AE and A1-A30 (1% annual chance): Zones AE and A1-A30 are the flood insurance rate zones that correspond to the 100-year floodplains that are determined in the FIS by detailed methods. In most instances, BFEs derived from the detailed hydraulic analyses are shown at selected intervals within this zone. Mandatory flood insurance purchase requirements apply. Zone X500 (0.2% annual chance) : Zone X500 is the flood insurance rate zone that corresponds to the 500-year floodplains that are determined in the Flood Insurance Study (FIS) by approximate methods. Because detailed hydraulic analyses are not performed for such areas, no BFEs (base flood elevations) or depths are shown within this zone. Zone VE (1% annual chance): Zone VE is the flood insurance rate zone that corresponds to the 100-year coastal floodplains that have additional hazards associated with storm waves. BFEs derived from the detailed hydraulic analyses are shown at selected intervals within this zone . Mandatory flood insurance purchase requirements apply. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 44 Locally Identified Areas of Flooding 1) Yirrell Beach: coastal surge and flooding during storm events 2) Shirley Street Neighborhood: low-lying street area and adjacent seawall experience wave overtopping and flooding during storm events 3) Lewis Lake: Serves as drainage area for large part of downtown area. Lake overflows during storm events and causes flooding in adjacent areas. 4) Ingleside Park: Backup and flooding due to lack of storm water storage capacity and undersized drains. Floods during high tide events coinciding with high precipitation events of greater than 1 inch. 5) Lower Nahant Avenue: coastal surge, high tide and high precipitation events all cause backup in undersized drain lines and flooding within the adjacent neighborhood. 6A) Woodside seawall and headwall on Boston Harbor: coastal surge flooding during storm events 6B) Somerset seawall and headwall on Boston Harbor: coastal surge flooding during storm events. 6C) Sargent Street seawall and headwall on Boston Harbor: coastal surge flooding during storm events. 6D) Cottage Park seawall and headwall on Boston Harbor: coastal surge flooding during storm events. 7) Coughlin Park: coastal erosion and flooding during higher northwest wind events and coastal storms. 8) Bayou Street Neighborhood- flooding due to undersized drainage line that backs up in high precipitation events. 12)Pico Avenue off of Sunnyside – seawall needs to be raised for 13-foot tide. 13) Morton Street and Banks. 14) Washington Street and River Road – floods during every large rain event. 15) Pleasant Street and Girdlestone Road – low-lying area floods, The area of Winthrop that floods the most frequently is Point Shirley. In addition to the eastern side of Point Shirley being directly impacted by ocean waves and storm surge, the western side of the Point is often impacted by the what local residents desc ribe as the “Boston Harbor bathroom effect” in which tidal driven storm surge causes water build -up in the Harbor and causes flooding on the western side of Point Shirley. Another area that floods frequently is the residential area surrounding Lewis Lake. Lewis Lake drains approximately half of the Town. Homes in this area flood because the lake is silted up which reduces its capacity. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 45 Flooding also occurs in the vicinity of Ingleside Park. The park is at sea level with a pipe that drains to the bay. There is a valve that shuts during heavy tides but the area may need a pump station as well. To help with flooding in this area, the Town has constructed dikes around two homes as a temporary solution. The south end of Yirrell Beach, in the vicinity of Wyman Street also experiences flooding because the seawall does not extend far enough. The road leading to the MWRA Deer Island wastewater facility is also prone to flooding during larger storm events. The seawall at Yirrell Beach to Deer Island remains one of the Town’s top priorit y hazard mitigation measures. This seawall is occasionally breached which results in sand coming up over the wall. Because the seawall ends at Wyman Street, this street floods, which can affect up to 40 homes. In 2003 the Town had to remove four feet of gravel that had washed up on Wyman Street. Repetitive Loss and Severe Repetitive Loss Properties As defined by the National Flood Insurance Program (NFIP), a repetitive loss property is any property which the NFIP has paid two or more flood claims of $1,000 or more in any given 10- year period since 1978. A Severe Repetitive Loss property consists of any NFIP-insured residential property that has met at least one of the following flood loss criteria since 1978: • 4 or more separate claim payments of more than $5,000 each (including building and contents payments); or • 2 or more separate claim payments (building payments only) where the total of the payments exceeds the current value of the property. There are 153 repetitive loss properties in Winthrop. These properties had a total of 489 losses, totaling $ 3,772,415 in building and contents damages. In addition there are 11 Severe Repetitive Loss properties that have had 11 losses totaling $654,231 . The total of all losses for RL and SRL properties in Winthrop is $ 4,426,646. Table 15 summarizes the number of repetitive loss and severe repetitive loss properties in Winthrop and the number of losses and insurance payments for building losses and building contents losses. Table 15. Summary of Repetitive Losses and Claims Repetitive Loss Properties Severe Repetitive Loss Properties Total Number of Properties 153 11 164 Number of Losses 489 63 552 Building Claim Payments $3,476,995 $588,955 $4,065,950 Contents Claim Payments $294,777 $65,202 $359,979 Total Claim Payments $3,772,415 $654,231 $4,426,646 Source: Massachusetts Emergency Management Agency TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 46 COASTAL EROSION Coastal shorelines change constantly in response to storms, seasons, sea level, and human alterations. Rising seas and more frequent and intense storms will tend to increase erosion, although some areas may actually accrete material due to localized variation in coastal dynamics. The severity of erosion is related to such factors as exposure to high energy waves, sediment size, sea level rise, near-shore bathymetry, and human interference with sediment supply. Coastal landforms such as coastal banks are essential to maintaining a supply of sediment to beaches and dunes. Where engineered structures are used to stabilize shorelines, the natural process of erosion is interrupted, decreasing the amount of sediment available and causing erosion to adjacent areas. Under conditions of reduced sediment, the ability of coastal resource areas such as dunes and beaches to provide storm damage prevention and flood control benefits is continually reduced. A major challenge is to ensure that regional sediment supplies are managed effectively and in ways that allow the beneficial storm damage prevention and flood control functions of natural coastal processes to continue — both for future projects and, where possible, existing coastal development. In Winthrop, there are many examples of both public and private infrastructure that are impacting sediment supplies to beaches. One area is the seawall along Winthrop Shore Drive and another is the private seawall along both sides of Shirley Street. Other areas with hard engineered infrastructure that may be impacting the supply of sediment to coastal beaches include Brewster and Grandview Avenues, Faunbar Avenue and Terrace Avenue. Coastal Erosion and Shoreline Change Coastal shorelines change constantly in response to wind, waves, tides, sea level fluctuation, seasonal and climatic variations, human alteration, and other factors that influence the movement of sand and material within a shoreline system. The loss (erosion) and gain (accretion) of coastal land is a visible result of the way shorelines are reshaped in the face of these dynamic conditions. Shorelines tend to change seasonally, accreting slowly during the summer months when sediments are deposited by relatively low energy waves and eroding dramatically during the winter when sediments are moved offshore by high-energy storm waves, such as those generated by nor’easters. Regardless of the season, coastal storms typically cause erosion. Coastal erosion and shoreline change can result in significant economic loss through the destruction of buildings, roads, infrastructure, natural resources, and wildlife habitats. Damage often results from the combination of an episodic event with severe storm waves and dune or bluff erosion. Some of the methods used by property owners to stop, or slow down, coastal erosion or shoreline change can actually exacerbate the problem. Attempting to halt the natural process of erosion with seawalls and other hard structures typically worsens the erosion in front of the structure, prevents any sediment behind the structure from supplying down drift properties with sediment and subjects down drift beaches to increased erosion. Without the sediment transport associated with erosion, some of the Commonwe alth’s and Winthrop’s greatest assets and attractions – beaches, dunes, barrier beaches, salt marshes, and estuaries are threatened and could be slowly diminished as the sediment sources that feed and sustain them are eliminated. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 47 Extent and Previous Occurrences The Massachusetts Coastal Erosion Commission published an assessment of coastal erosion in 2015. A shoreline characterization project was implemented to categorize the land uses and natural resources potentially at risk from coastal erosion. The results of the characterization provide a baseline from which to monitor and identify landscape-level trends and patterns for evaluating adaptation and hazard mitigation strategies for a particular location or region. The Commission assessed the trends of coastal erosion by examining the results of the Massachusetts Shoreline Change Project and providing a summary assessment of past shoreline changes. Launched in 1989, the Shoreline Change Project analyzed data from historical and modern sources, mapping local high water line and developing shoreline change rates over both a long-term period (from the mid-1800s to 2009) and a short-term period (from 1970-2009) These data provide insight into the historical migration of the shoreline and erosional hot spots. The results of the shoreline characterization were used to analyze shoreline change rates for Winthrop, including long-term and short-term erosion and accretion trends The analysis took into account various types of shoreline, which are displayed in Figure 18, showing the percent of each type. Figure 18: Percent of Assessed Shoreline by Type Source: Report of the Mass. Coastal Erosion Commission, 2015 The rates of shoreline erosion or accretion for Winthrop are shown in Table 16. The long- term accretion rate since the mid- 1800’s was 0.4 feet/year. The short-term accretion rate from 1970 to 2009 was the same. Table 16: Average shoreline change and Uncertainty Source: Report of the Mass. Coastal Erosion Commission, 2015 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 48 Table 17 shows both long-term and short-term rates of change for three types of shoreline in Winthrop. The highest rate of accretion is associated with Beach, over long-term. The erosion rates for Bank ranged from -0.10 feet/year short-term to 0.15 feet/year In the long-term. Table 17 Average shoreline change by shoreline type Source: Report of the Mass. Coastal Erosion Commission, 2015 CZM Coastal Erosion Viewer Massachusetts Coastal Zone Management (MA CZM) in cooperation with the U. S. Geological Survey (USGS) provides shoreline change data for the Massachusetts coast. The most recently available data provide long- term (1800’s – 2014) and short-term (1970-2014) data. The analysis for Winthrop shows somewhat different patterns of erosion from the long-term to the short-term records. see Figures 19A and 19B). This illustrates the effects of climate trends along some parts of the shoreline, as erosion rates in some areas have generally increased since the 19 th and 20 th centuries. The CZM Coastal Erosion Viewer provides more detailed views of historic shoreline changes along a series of transects of the shoreline. A detailed transects for Winthrop is shown in Figure 20. The yellow transects indicate no statistical change while the red transects indicate net shoreline loss . This is the section of Winthrop’s shoreline that has experienced the most significant change. Coastal Erosion and Climate Change As sea level continues to rise, coastal erosion will increase over time most likely with increasing frequency and severity. This represents a significant long-term hazard for the Town of Winthrop. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 49 Figure 19A: Long-Term Coastal Erosion in Winthrop, 1840s-2018 Source : MA Coastal Zone Management, Coastal Erosion Viewer TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 50 Figure 19B: Short-Term Coastal Erosion in Winthrop, 1970-2019 Source : MA Coastal Zone Management, Coastal Erosion Viewer TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 51 Figure 20: Winthrop Shoreline Change (1847-2008) Source : MA Coastal Zone Management, Coastal Erosion Viewer TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 52 TSUNAMIS A tsunami is a surge of ocean water typically caused by an offshore earthquake. FEMA defines tsunami as a series of large seismic sea waves created by an underwater disturbance caused by geologic activity such as earthquakes, volcanic eruptions, or underwater landslides. The severity of a tsunami is related to its wave height at the shore, and the extent of runup. Tsunami wave action over the shore is variable and mainly dependent of the combination of both submarine and land topography and the orientation of the arriving waves. The extent of damage and impact from tsunami depends upon the source and severity of onset on the tide cycle. Coastal areas that are potentially at greater risk are less than 25 feet above sea level and within a mile of the shoreline. As such, Winthrop would be considered vulnerable to coastal inundation from tsunami. While all of the coast of Massachusetts could potentially be subject to a tsunami, Massachusetts has never experienced a significant tsunami. Probability of Future Occurrence According to the West Coast and Alaska Tsunami Warning Center, an Atlantic based tsunami threat level for the US Atlantic coast is low when compared to the Pacific and Caribbean coasts. Geophysics specialists from the U.S. Geologic Survey and the Woods Hole Oceanographic Institute have researched the Georges Bank Lower Slope of the North Atlantic Ocean and the relationship between submarine landslides and earthquakes (see Figure 21). Figure 21 - Atlantic Based Tsunami- Potential Threat T he most likely source would be a landslide that happens underwater about 215 miles offshore in an area known as the Continental Slope. The US Geologic Survey has researched the probability of a landslide on the Continental Shelf, and the likelihood that a tsunami will hit the Atlantic coast TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 53 is considered to be fairly low. Based on the record of previous occurrences, Tsunami in Winthrop is a Very Low frequency event as defined by the Resilient MA Plan Tsunamis and Climate Change Unlike most other coastal hazards, Tsunamis are events driven by geological processes, principally earthquakes and undersea landslides, which are not likely to be related to climate change. However. according to the Resilient MA Plan, collapse of glaciers resulting from a warming climate could cause landslides that could generate tsunamis more powerful than those caused by earthquakes. DAM HAZARDS Dam failure can occur as a result of structural failure, independent of a hazard event, or as the result of the impacts of a hazard event such as flooding associated with storms or an earthquake. In the event of a dam failure, the energy of the water stored behind even a small dam can cause loss of life and property damage if there are people or buildings downstream. The number of fatalities from a dam failure depends on the amount of warning provided to the population and the number of people in the area in the path of the dam’s floodwaters. Dam failure is a highly infrequent occurrence, but a severe incident could result in loss of lives and significant property damage. Since 1984, three dams have failed in or very near to Massachusetts, one of which resulted in a death . There are no publicly or privately owned dams in Winthrop listed by the Department of Conservation Dam Safety Office. HURRICANES AND TROPICAL STORMS Wind-related hazards include hurricanes, tropical storms, and tornadoes as well as high winds during Nor’easters and thunderstorms. Information on wind related hazards can be found on Map 5 in Appendix A, which indicates that the 100-year wind speed in Winthrop is 110 miles per hour. Hurricanes begin as tropical storms over the warm moist waters of the Atlantic, off the coast of West Africa near the equator. As the moisture evaporates, it rises until enormous amounts of heated, moist air are twisted high in the atmosphere. The winds begin to circle counterclockwise north of the equator or clockwise south of the equator. The center of the hurricane is called the eye. Tropical cyclones (Tropical Depressions, Tropical Storms, and Hurricanes) form over the warm, moist waters of the Atlantic, Caribbean, and Gulf of Mexico. When water temperatures are at least 80° F, hurricanes can grow and thrive, generating enormous amounts of energy, which is released in the form of numerous thunderstorms, flooding rainfall, and, very damaging winds. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 54 The damaging winds help create a dangerous storm surge (rise in the water above the normal astronomical tide). A Tropical Depression is declared when there is a low pressure center in the tropics with sustained winds of 25-33 mph. A Tropical Storm, which is given a name, is defined as having sustained winds from 34-73 mph. If sustained winds reach 74 mph or greater, it becomes a Hurricane. Hurricanes can range from compact storms only 50 miles across, to huge storms, as much as 500 miles wide -- Hurricane Allen in 1980 took up the entire Gulf of Mexico. There generally are two source regions for the storms that have the potential to strike New England: 1) off the Cape Verde Islands near the west coast of Africa and 2) in the Bahamas. The Cape Verde storms tend to be very large in diameter, since they have a week or more to traverse the Atlantic Ocean and grow. Bahamas’ storms tend to be sma ller, but they can also be just as powerful and their effects can reach New England in only a day or two. A hurricane is strongest as it travels over the ocean and is particularly destructive to coastal property as the storm hits the land. The Town's entire area is vulnerable to hurricanes. Hurricanes occur between June and November. Hurricane intensity is measured according to the Saffir/Simpson scale, which categorizes hurricane intensity linearly based upon maximum sustained winds, barometric pressure, and storm surge potential. These are combined to estimate potential damage. The following gives an overview of the wind speeds, surges, and range of damage caused by different hurricane categories: Scale No. (Category) Winds(mph) Storm Surge (ft) Potential Damage 1 74 – 95 4 - 5 Minimal 2 96 – 110 6 - 8 Moderate 3 111 – 130 9 - 12 Extensive 4 131 – 155 13 - 18 Extreme 5 > 155 >18 Catastrophic Source: NOAA Previous Occurrences Since 1900, 39 tropical storms have impacted New England (NESEC). Massachusetts has experienced approximately 32 tropical storms, nine Category 1 hurricanes, five Category 2 hurricanes and one Category 3 hurricane. A hurricane or storm track is the line that delineates the path of the eye of a hurricane or tropical storm. A hurricane or tropical storm track is the line that delineates the path of the eye of the hurricane or storm. As shown in Map 5 in Appendix A, no hurricanes or tropical storms have tracked directly over Winthrop, but several passed very close to the town, one in 1902, and two more in 1923. However, hurricanes have regional impacts, and Winthrop experiences the impacts of hurricanes and tropical storms regardless of whether the storm track passes directly through the Town. Storms that track west of the town result in stronger winds, while those that pass to the east may bring TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 55 more rainfall. Numerous hurricanes have affected the communities of eastern Massachusetts over the last century(see Table 18). Table 18 Hurricane Records for Massachusetts, 1908 - 2025 Hurricane Event Date Hurricane of 1908 May 24-31, 1908 Hurricane of 1915 July 31, 1915 Hurricane of 1916 July 10-22, 1916 Great New England Hurricane September 21, 1938 Great Atlantic Hurricane September 14-15, 1944 Hurricane Doug September 11-12, 1950 Hurricane Carol August 31, 1954 Hurricane Edna September 11, 1954 Hurricane Diane August 17-19, 1955 Hurricane Donna September 12, 1960 Hurricane Gloria September 27, 1985 Hurricane Bob August 19, 1991 Hurricane Bertha July 5 - 17, 1996 Hurricane Hanna August 28, 2008 Hurricane Earl September 4, 2010 Tropical Storm Irene August 28, 2011 Hurricane Sandy October 29-30, 2012 Source: National Oceanic and Atmospheric Administration The two most recent hurricanes, Irene from August 21 – 30, 2011and Sandy from October 22 – 31, 2012 fortunately did not track directly over Winthrop). Hurricane Sandy was a Category 3 hurricane at its peak intensity and weakened to a Category 2 off the northeastern Atlantic coast. Hurricane Sandy became the largest Atlantic hurricane on record with winds spanning 1,100 miles. Strong tropical force winds from the northeast quadrant of the post tropical cyclone, Sandy developed into a super storm nor’easter that impacted Winthrop and Suffolk County (Figure 22). Winthrop closed the tidal gate on Winthrop Shore Drive at 7 A.M. on the morning of Sandy’s arrival. News reports for Hurricane Sandy indicated key findings, as reported by the Winthrop Transcript on November 1, 2012: “(Fire Chief) Flanagan said there was some personal property damage such as electrical services being dismantled from homes and four boats breaking loose in the harbor. The chief also reported that at the peak of the storm 2,100 customers were without electrical power. The Winthrop Fire Department staged fire apparatus and ambulances on Point Shirley during periods of high tides. Shirley Street at Tewksbury Street became impassable for a period of a few hours during Monday morning’s high tide. The chief also said that tw o telephone poles went down on Putnam Street while another pole broke off at the base on Veterans Road. At 10 a.m. on Monday, Flanagan had the Medical Reserve Corps (MRC) open a shelter at the Cummings School in case of tidal concerns.” TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 56 Figure 22: Winthrop Shore Drive, October 28, 2012, Hurricane Sandy Photo: courtesy of Winthrop Transcript Hurricanes typically have regional impacts beyond their immediate tracks. Falling trees and branches are a significant problem because they can result in power outages when they fall on power lines or block traffic and emergency routes. Hurricanes are a town-wide hazard in Winthrop. Potential hurricane damages to Winthrop have been estimated using HAZUS-MH. Total damages are estimated at $7.2 million for a100-year frequency hurricane and $30.9 million for a 500-year frequency hurricane. Other potential impacts such as debris and evacuation needs are detailed in Table xx. Probability of Future Occurrence Based on records of previous occurrences, hurricanes in Winthrop are a medium frequency event as defined by the Resilient MA Plan. This hazard occurs from once in 5 years to once in 50 years, or a 2% to 20% chance per year. Hurricanes and Climate Change Climate models suggest that hurricanes and tropical storms will become more intense as warmer ocean waters provide more fuel for the storms. In addition, rainfall amounts associated with hurricanes are predicted to increase because warmer air can hold more water vapor TORNADOES A tornado is a violent windstorm characterized by a twisting, funnel-shaped cloud. These events are spawned by thunderstorms and occasionally by hurricanes and may occur singularly or in multiples. T hey develop when cool air overrides a layer of warm air, causing the warm air to rise rapidly. Most vortices remain suspended in the atmosphere. Should they touch down, they become a force of destruction. Some ingredients for tornado formation include: TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 57 • Very strong winds in the mid and upper levels of the atmosphere • Clockwise turning of the wind with height (from southeast at the surface to west aloft) • Increasing wind speed with altitude in the lowest 10,000 feet of the atmosphere (i.e., 20 mph at the surface and 50 mph at 7,000 feet.) • Very warm, moist air near the ground with unusually cooler air aloft • A forcing mechanism such as a cold front or leftover weather boundary from previous shower or thunderstorm activity Tornado damage severity is measured by the Fujita Tornado Scale, in which wind speed is not measured directly but rather estimated from the amount of damage. As of February 01, 2007, the National Weather Service began rating tornados using the Enhanced Fujita-scale (EF-scale). It is considerably more complicated than the original F-scale, and it allows surveyors to create more precise assessments of tornado severity. The EF-scale is summarized in Table 19. Table 19: Enhanced Fujita Scale Source: SHMCAP 2018 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 58 The frequency of tornadoes in eastern Massachusetts is relatively low; on average, there are six tornadoes that touchdown somewhere in the Northeast region every year. The strongest tornado in Massachusetts history was the Worcester Tornado in 1953 (NESEC). The most recent significant tornado event in Massachusetts was in Springfield in 2011. This tornado caused significant damage and resulted in 4 deaths in June of 2011. Although there have been no recorded tornadoes within the Town of Winthrop, a tornado struck nearby Chelsea and Revere in 2014. The tornado touched down in Chelsea just south of Route 16 and moved north into R evere’s business district along Broadway and ended near the intersection of Routes 1 and 60. The path was approximately two miles long and 3/8 mile wide, with wind speeds up to 120 miles per hour. Figure 23 shows the tornado’s track in Chelea and Revere and illustrates its proximity to Winthrop. This is the only tornado recorded for Suffolk County from 1950 to 2025. This tornado resulted in $4 million in damage, two injuries, and no fatalities , as summarized in Table 20. Most of the damage was rated EF-1, but EF-2 rated damage did occur near Revere Beach Parkway. Windows were blown out of Revere City Hall and the roof was damaged. Sixty- four structures sustained damage that ranged from siding torn off to roofs lifted or blown off. Thirteen of these structures were deemed uninhabitable.. Trees fell on cars, a few of these crushed. Revere High School also sustained damage. Police reported a car that had been overturned at the intersection of Revere Street and Carleton Avenue. Near the rotary at Route 60 and Broadway, a billboard was blown onto several cars. The city set up a shelter at a local school for displaced residents. National Grid reported that 3,000 homes were without power. Figure 23 – Chelsea/Revere Tornado of 2014 Source: National Centers for Environmental Information TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 59 Table 20 - Tornado Records for Suffolk County Date Fujita Fatalities Injuries Damage 70/28/2014 EF2 0 2 $4,000,000 Source: National Centers for Environmental Information Buildings constructed prior to current building codes may be somewhat more vulnerable to damages caused by tornadoes. Evacuation of impacted areas may be required on short notice. Sheltering and mass feeding efforts may be required along with debris clearance, search and rescue, and emergency fire and medical services. Key routes may be blocked by downed trees and other debris, which in Winthrop could be a significant hazard since there are only two routes connecting the Town to the mainland. Power outages are also typically associated with tornadoes. Although tornadoes are a potential Town-wide hazard in Winthrop, tornado impacts are relatively localized compared to severe storms and hurricanes, as the Rever tornado illustrates. Damages from any tornado in Winthrop would greatly depend on the track of the tornado. Generally, the more densely developed areas in the northern part of town could sustain more building damage in the event of a tornado in Winthrop. Probability of Future Occurrence Based on the record of previous occurrences since 1950, Tornado events in Winthrop are a Low frequency event as defined by the Resilient MA Plan. This hazard is likely to occur at least once by the end of the century. Tornadoes and Climate Change According to the Resilient MA Plan, it is possible that severe thunderstorms which can include tornadoes may increase in frequency and intensity. However, scientists have less confidence in the models that seek to project future changes in tornado activity. The Massachusetts 2022 Climate Change Assessment does not include information related to tornadoes. SEVERE WINTER STORMS (NOR’EASTERS / BLIZZARDS) Winter storms, including nor’easters, heavy snow, blizzards, and ice storms, are the most common and most familiar of the region’s hazards that affect large geographic areas. The majority of blizzards and ice storms in the region cause more inconvenience than serious property damage, injuries, or deaths. However, periodically, a storm will occur which is a true disaster, and necessitates intense large-scale emergency response. The strongest among these are typically nor’easters. NOR’EASTER S A northeast coastal storm, known as a nor’easter, is typically a large counterclockwise wind circulation around a low-pressure center. Featuring strong northeasterly winds blowing in from the ocean over coastal areas, nor’easters are relatively common in the winter months in New England occurring one to two times a year. The storm radius of a nor’easter can be as much as 1,000 miles and these storms feature sustained winds of 20 to 40 mph with gusts of up to 70 mph (Figure 24). These storms are accompanied by heavy rains or snows, depending on temperatures. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 60 Figure 24 – Nor’easter Satellite Image Source: The Geostationary Operational Environmental Satellite Program (GOES), A joint effort of NASA and NOAA.. The Dolan- Davis classification system for Nor’easters was developed to complement the Saffir - Simpson scale used for hurricanes. The scale is based on mean wave height caused by the Nor’easter – different from the Saffir-Simpson classification of hurricanes based on wind speed. The scale was developed using data from 1,347 Nor’easters over a forty-year time frame. Robert Dolan and Robert Davis developed the scale to classify Nor’easters from Class I through Class V. Table 21 below summarizes each class of storm. Table 21. Dolan- Davis Classification System for Nor’easters Storm Class Mean Wave Height (m) Beach Erosion Property Damage Class I (weak) 2.0 Minor None Class II (moderate) 2.5 Moderate None Class III (significant) 3.2 Extends across beach Moderate Class IV (severe) 5.0 Severe with recession Loss of structures at community scale Class V (extreme) 6.8 Extreme Extensive regional scale losses in millions of dollars Landsea, C. (2009, February 6). FAQ: Hurricanes, Typhoons, and Tropical Cyclones and Williams, J. (2005, May 17). Hurricane scale invented to communicate storm danger. Previous occurrences of nor’easters include the storm events included in Table 22. Many of the historic flood events identified in the previous section were precipitated by nor’easters, including the “Perfect Storm” event in 1991. More recently, large nor’easters in 2015 and 2018 caused significant damage across the coast. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 61 Table 22 : Nor’easter Events for Massachusetts, 1978 - 2024 Date Nor’easter Event February 1978 Blizzard of 1978 October 1991 Severe Coastal Storm (“Perfect Storm”) December 1992 Great Nor’easter of 1992 January 2005 Blizzard/Nor’easter October 2005 Coastal Storm/Nor’easter April 2007 Severe Storms, Inland & Coastal Flooding/Nor’easter January 2011 Winter Storm/Nor’easter October 2011 Severe Storm/Nor’easter February 2013 Blizzard of 2013 January 2015 Blizzard of 2015 March 2015 March 2015 Nor’easters January 2018 January 2018 March 2018 March 2018 Winthrop is vulnerable to both the wind and precipitation that accompanies nor’easters. High winds can cause damage to structures, fallen trees, and downed power lines leading to power outages. Intense rainfall can overwhelm drainage systems causing localized flooding of streets as well as localized flooding of residential and business structures. Fallen tree limbs as well as heavy snow accumulation and intense rainfall can impede local transportation corridors, and block access for emergency vehicles. Due to its location on the coast, the entire Town is at risk from the wind, rain or snow impacts from a nor’easter, depending on the track and radius of the storm . Based on the record of previous occurrences, nor’easters in Winthrop are high frequency events as defined by the Resilient MA Plan. This hazard is almost certain to occur at least once a year. BLIZZARDS & HEAVY SNOW Winter storms are a combination hazard because they often involve wind, ice, and heavy snow fall. The National Weather Service defines “heavy snow fall” as an event generating at least four inches of snowfall within a 12-hour period (NOAA, 2009). Blizzards and winter storms are often associated with a nor’easter event (see nor’easters section above). A blizzard is a winter snowstorm with sustained or frequent wind gusts to 35 mph or more, accompanied by falling or blowing snow which reduces visibility to or below ¼ mile. These conditions must be the predominant conditions over a three-hour period. Extremely cold temperatures are often associated with blizzard conditions but are not a formal part of the definition. The hazard related to the combination of snow, wind, and low visibility significantly increases when temperatures drop below 20 degrees. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 62 The Regional Snowfall Index (RSI) characterizes and ranks the severity of northeast snowstorms. RSI has five categories: Extreme, Crippling, Major, Significant, and Notable. RSI scores are a function of the area affected by the storm, the amount of snow, and the number of people living in the path of the storm. The largest RSI values result from storms producing heavy snowfall over large areas that include major metropolitan centers. The RSI categories are shown in Table 23. Table 23: Regional Snowfall Index Category RSI Value Description 1 1 – 3 Notable 2 3-6 Significant 3 6-10 Major 4 10-18 Crippling 5 18+ Extreme Source: 2018 SHMCAP The best available local data on past occurrences and impacts of winter storm events are reported for Suffolk County by the National Centers for Environmental Information (NCEI). From 2010 through 2024, Suffolk County experienced 51 winter storm events, including three blizzards, resulting in one injury, no deaths, and $703,100 in property damage, as shown in Table 24. Table 24: Winter Storms, Heavy Snow and Blizzards in Suffolk County, 2010 - 2024 Date Event Deaths Injuries Property Damage ($) 12/26/2010 Winter Storm 0 0 0 1/12/2011 Winter Storm 0 0 50000 1/21/2011 Winter Storm 0 0 0 1/26/2011 Heavy Snow 0 0 0 2/1/2011 Winter Storm 0 0 432000 1/21/2012 Winter Storm 0 0 0 2/8/2013 Heavy Snow 0 0 0 2/8/2013 Blizzard 0 0 0 2/17/2013 Winter Storm 0 0 0 3/7/2013 Heavy Snow 0 0 0 3/18/2013 Heavy Snow 0 0 0 12/17/2013 Heavy Snow 0 0 0 1/2/2014 Heavy Snow 0 0 0 2/5/2014 Heavy Snow 0 0 0 1/24/2015 Heavy Snow 0 0 0 1/26/2015 Blizzard 0 0 0 2/2/2015 Heavy Snow 0 0 0 2/8/2015 Heavy Snow 0 0 0 2/14/2015 Heavy Snow 0 0 0 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 63 1/23/2016 Heavy Snow 0 0 0 2/5/2016 Heavy Snow 0 0 10000 2/8/2016 Heavy Snow 0 0 0 3/21/2016 Winter Storm 0 0 0 4/4/2016 Winter Storm 0 0 0 12/17/2016 Winter Storm 0 0 0 1/7/2017 Winter Storm 0 0 0 2/8/2017 Winter Storm 0 0 150000 2/9/2017 Winter Storm 0 0 0 3/14/2017 Heavy Snow 0 0 0 12/9/2017 Winter Storm 0 0 0 12/22/2017 Winter Storm 0 1 5000 12/25/2017 Winter Storm 0 0 2000 1/4/2018 Winter Storm 0 0 0 2/7/2018 Winter Storm 0 0 40000 2/17/2018 Winter Storm 0 0 0 3/7/2018 Winter Storm 0 0 0 3/13/2018 Blizzard 0 0 10000 1/19/2019 Winter Storm 0 0 0 2/18/2019 Winter Storm 0 0 0 3/3/2019 Winter Storm 0 0 0 10/30/2020 Winter Storm 0 0 2000 12/16/2020 Heavy Snow 0 0 0 2/7/2021 Heavy Snow 0 0 0 1/7/2022 Heavy Snow 0 0 0 1/28/2022 Heavy Snow 0 0 500 2/25/2022 Heavy Snow 0 0 0 1/20/2023 Heavy Snow 0 0 0 1/23/2023 Heavy Snow 0 0 600 2/23/2023 Heavy Snow 0 0 0 3/3/2023 Heavy Snow 0 0 0 3/14/2023 Heavy Snow 0 0 1000 TOTAL 0 1 $703,100 Source: NOAA, National Centers for Environmental Information Another indication of previous severe winter events is the list of Presidentially declared disasters for blizzards and snowstorms. There have been 14 in Massachusetts since 1978, as shown in Table 25. The most significant single winter storm was the “Blizzard of 1978,” which resulted in over three feet of snowfall and multiple day closures of roadways, businesses, and schools. The record snowfall of January 2015 resulted from a series of storms over that month. The most recent significant winter event was Winter Storm Kenan (January 29, 2022), which resulted in 30.9” of snow in Massachusetts (Stucker, 2022). TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 64 T able 25: Winter-Related Federal Disaster Declarations, 1978-2023 Disaster Name Date of Event Coastal Storms, Flood, Ice & Snow February 1978 Winter Coastal Storm December 1992 Blizzard March 1993 Blizzard January 1996 Snowstorm March 2001 Snowstorm February 2003 Snowstorm December 2003 Snowstorm January 2005 Severe Winter Storm, Snowstorm January 2011 Severe Winter Storm, Snowstorm, Flooding February 2013 Severe winter storm, snowstorm, flooding January 2015 Severe winter storm and Snowstorm March 2018 Severe winter storm and flooding March 2018 Severe winter storm and snowstorm January 2022 Sources: OpenFEMA Dataset: Disaster Declarations and FEMA Declared Disasters Winter storms are a community-wide hazard in Winthrop. Map 6 in Appendix A illustrates the average annual average snowfall in Winthrop, which is between 48 to 72 inches. The majority of blizzards and ice storms in the region cause more inconvenience than serious property damage, injuries, or deaths. However, periodically, a storm will occur which is a true disaster, and necessitates intense large-scale emergency response. The impacts of winter storms are often related to the weight of snow and ice, which can cause roof collapses and also causes tree limbs to fall. This in turn can cause property damage and potential injuries. Power outages may also result from fallen trees and utility lines. A number of public safety issues can arise during snowstorms. Impassible streets are a challenge for emergency vehicles and affect residents and employers. Large piles of snow can also block sight lines for drivers, particularly at intersections. Refreezing of melting snow can cause dangerous roadway conditions. In addition, transit operations may be impacted, as they were in the 2015 blizzards which caused the closure of the MBTA system for one day and limited services on the commuter rail for several weeks. Managing snow removal can be an expensive and challenging task for a community like Winthrop. Narrow streets, lack of off-street parking options and limited areas to store plowed snow can hinder plowing and emergency vehicle access. The Winthrop DPW works to clear roads as requested by emergency service providers and carries on general snow removal operations. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 65 Probability of Future Occurrences Blizzards are considered high frequency events based on past occurrences, as defined by the Resilient MA Plan. This hazard is almost certain to occur at least once a year. WINTER ICE STOMS The ice storm category covers a range of different weather phenomena that collectively involve rain or snow being converted to ice in the lower atmosphere leading to potentially hazardous conditions on the ground. Ice storm conditions are defined by liquid rain falling and freezing on contact with cold objects, creating ice buildups of one-fourth of an inch or more. An ice storm warning, which is now included in the criteria for a winter storm warning, is issued when a half inch or more of accretion of freezing rain is expected. Sleet and hail are other forms of frozen precipitation. Sleet occurs when raindrops fall into subfreezing air thick enough that the raindrops refreeze into ice before hitting the ground. The difference between sleet and hail is that sleet is a wintertime phenomenon whereas hail falls from convective clouds (usually thunderstorms), often during the warm spring and summer months (a description of hail is included in a subsequent report section). Another form of freezing precipitation is ice pellets, which occur when snowflakes melt into raindrops as they pass through a thin layer of warmer air. The raindrops then refreeze into particles of ice when they fall into a layer of sub-freezing air near the surface of the earth. The extent of ice storms is measured by the Sperry-Piltz Ice Accumulation Index (SPIA®); see Table 23. The SPIA Index is to ice storms what the Enhanced Fujita Scale is to tornadoes, and what the Saffir – Simpson Scale is to hurricanes. The SPIA® Index, is a forward-looking, ice accumulation and ice damage prediction index that uses an algorithm based on three key parameters: 1) Storm total rainfall, converted to ice accumulation 2) Wind 3) Temperatures during the event period These parameters, when used in conjunction with digital forecasts from local NWS Weather Forecast Offices (WFOs), have been shown to accurately predict the duration, intensity and damage capability of ice storms. The SPIA® Index predicts the projected footprint, total ice accumulation, and resulting potential damage from approaching ice storms. It is a tool to be used for risk management and/or winter weather preparedness Table 26). The best available data on previous ice storm events are recorded for Suffolk County by NOAA’s National Centers for Environmental Information (NCEI) Storm Events Database. Suffolk County, which includes the Town of Winthrop, does not have any ice storms recorded since 2000. The Town’s location in the milder coastal region makes it less vulnerable to ice storms than adjacent inland areas at higher elevations such as Middlesex County and central to western Massachusetts. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 66 Table 26: Sperry-Piltz Ice Accumulation Index (SPIA®) Source: SPIA® Index, www.spia-index.com/ Should an ice storm occur in Winthrop, the greatest hazard is created by freezing rain conditions, which is rain that freezes on contact with hard surfaces leading to a layer of ice on roads, walkways, trees, and other surfaces. The conditions created by freezing rain can make driving particularly dangerous and emergency response more difficult. The weight of ice on tree branches can also lead to falling branches causing power outages and blocking roadways. The impacts of winter storms may also include roof collapses and property damage and injuries related to the weight of snow and ice. Probability of Future Occurrence In Winthrop, ice storms are considered to be low frequency events based on past occurrences, as defined by the Resilient MA Plan. This hazard may occur once in 5 years to once in 50 years, with 2% to 20% chance of occurring each year. Winter Weather and Climate Change As with hurricanes, warmer ocean water and air will provide more fuel for winter storms. According to the 2018 SHMCAP it appears that Atlantic coast nor’easters are increasing in TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 67 frequency and intensity. Further, the SHMCAP notes that research suggests that warmer weather in the Arctic is producing changes to atmospheric circulation patterns that favor the development of winter storms in the Eastern United States. There is also some indication that as winters warm, temperatures may be more likely to produce icing conditions. Massachuset ts’ 2022 Climate Change Assessment predicts more mild winters, increased precipitation in the winter months, and multiple freeze-thaw cycles every winter due to warming temperatures . OTHER SEVERE WEATHER (THUNDERSTOMS / HAIL) THUNDERSTORMS While less severe than the other types of storms discussed, thunderstorms can lead to localized damage and represent a hazard risk for communities. A thunderstorm typically features lightning, strong winds, and rain and/or hail. Thunderstorms sometime give rise to tornados. On average, these storms are only around 15 miles in diameter and last for about 30 minutes. A severe thunderstorm can include winds of close to 60 mph and rain sufficient to produce flooding. The severity of thunderstorms ranges from commonplace and of short duration to intense storms that cause damage due to high winds, flooding, or lightning strikes. The extent of damages from high winds is described by the Beaufort Wind Scale (Table 27), which was developed in 1805 by Sir Francis Beaufort of the U.K. Royal Navy. Table 27 Beaufort Wind Scale Force Wind (Knots) WMO Classifi- cation Appearance of Wind Effects On the Water On Land 0 < 1 Calm Sea surface smooth and mirror-like Calm, smoke rises vertically 1 1-3 Light Air Scaly ripples, no foam crests Smoke drift indicates wind direction, still wind vanes 2 4-6 Light Breeze Small wavelets, crests glassy, no breaking Wind felt on face, leaves rustle, vanes begin to move 3 7-10 Gentle Breeze Large wavelets, crests begin to break, scattered whitecaps Leaves and small twigs constantly moving, light flags extended 4 11-16 Moderate Breeze Small waves 1-4 ft. becoming longer, numerous whitecaps Dust, leaves, and loose paper lifted, small tree branches move 5 17-21 Fresh Breeze Moderate waves 4-8 ft taking longer form, many whitecaps, some spray Small trees in leaf begin to sway TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 68 6 22-27 Strong Breeze Larger waves 8-13 ft, whitecaps common, more spray Larger tree branches moving, whistling in wires 7 28-33 Near Gale Sea heaps up, waves 13-19 ft, white foam streaks off breakers Whole trees moving, resistance felt walking against wind 8 34-40 Gale Moderately high (18-25 ft) waves of greater length, edges of crests begin to break into spindrift, foam blown in streaks Twigs breaking off trees, generally impedes progress 9 41-47 Strong Gale High waves (23-32 ft), sea begins to roll, dense streaks of foam, spray may reduce visibility Slight structural damage occurs, slate blows off roofs 10 48-55 Storm Very high waves (29-41 ft) with overhanging crests, sea white with densely blown foam, heavy rolling, lowered visibility Seldom experienced on land, trees broken or uprooted, "considerable structural damage" 11 56-63 Violent Storm Exceptionally high (37-52 ft) waves, foam patches cover sea, visibility more reduced 12 64+ Hurricane Air filled with foam, waves over 45 ft, sea completely white with driving spray, visibility greatly reduced Source: NOAA Storm Prediction Center In the National Risk Index, a Lightning Risk Index score and rating represent a community's relative risk for Lightning when compared to the rest of the United States. A Lightning Expected Annual Loss score and rating represent a community's relative level of expected building and population loss each year due to Lightning when compared to the rest of the United States. Winthrop is in the Low to Relatively Low categories of Lightning Risk as shown in Figure 25. The amount of rainfall expected for storms of various durations and recurrence intervals, from 5 minutes to 60 days, and from annual recurrence to 1,000 years, is provided by NOAA’s Atlas 14. The Depth-Duration-Frequency curves are shown in Figure 26. For example, the chart shows the range of expected precipitation for a 12-hour rainfall ranges from about 2 inches for annual storm and 10 inches for a storm of 100-year frequency. The best available data on previous occurrences of thunderstorms in Winthrop are from the NOAA National Centers for Environmental Information (NCDC) for Suffolk County. Between the years 2010 and 2024 NCEI records show 34 thunderstorm events in Suffolk County (Table 28). These storms resulted in a total of $ 678,200 in property damages. There were no injuries or deaths. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 69 Figure 25: National Risk Index for Lightning Source: FEMA National Risk Index Figure 26: Depth-Duration-Frequency Curve Source: NOAA Atlas 14 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 70 Table 28: Suffolk County Thunderstorm Events, 2010 through 2024 Date Max. Wind Speed (mph) Deaths Injuries Property Damage 6/1/2010 50 0 0 10000 6/3/2010 50 0 0 500 6/6/2010 50 0 0 145000 6/24/2010 50 0 0 15000 6/1/2011 50 0 0 20000 8/19/2011 50 0 0 15000 6/8/2012 50 0 0 30000 9/8/2012 50 0 0 5000 7/3/2014 50 0 0 15000 8/4/2015 50 0 0 50000 2/25/2016 60 0 0 20000 6/29/2016 50 0 0 15000 7/18/2016 50 0 0 70000 7/23/2016 50 0 0 83000 6/27/2017 50 0 0 1000 7/12/2017 50 0 0 1000 8/2/2017 50 0 0 1000 9/14/2017 57 0 0 25000 7/17/2018 45 0 0 1300 7/31/2019 65 0 0 39500 8/7/2019 50 0 0 300 5/15/2020 50 0 0 3500 6/28/2020 50 0 0 1800 7/23/2020 50 0 0 800 10/7/2020 57 0 0 0 6/29/2021 50 0 0 500 6/30/2021 50 0 0 1800 7/7/2021 55 0 0 1000 7/27/2021 61 0 0 86900 5/22/2022 50 0 0 11800 8/7/2022 50 0 0 0 7/25/2023 50 0 0 0 7/27/2023 50 0 0 5000 6/14/2024 50 0 0 2500 TOTAL 0 0 $678.200 Source: NOAA, National Centers for Environmental Information Magnitude refers to maximum wind speed in knots. Severe thunderstorms are a Town-wide hazard for Winthrop. The Town's vulnerability to severe thunderstorms is similar to that of Nor'easters. High winds can cause falling trees and power outages, as well as obstruction of key routes and emergency access. Heavy precipitation may also cause localized flooding, both riverine and urban drainage related. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 71 Probability of Future Occurrence Based on the record of previous occurrences, severe thunderstorms in Winthrop are high frequency events as defined by the Resilient MA Plan. This hazard occurs more frequently than once in 5 years (greater than 20% per year). Thunderstorms and Climate Change As noted previously, the intensity of rainfall events has increased significantly, and those trends are expected to continue. Neither the SHMCAP, nor the 2022 Massachusetts Climate Change Assessment, specifically address whether climate will affect the intensity or frequency of thunderstorms. HAIL Hail and sleet are forms of frozen precipitation. Hail occurs when precipitation falls through subfreezing air thick enough that the raindrops freeze into ice before hitting the ground. While sleet is a wintertime phenomenon, hail falls from convective clouds (usually thunderstorms), often during the warm spring and summer months. Hail size typically refers to the diameter of the hailstones. Warnings and reports may report hail size through comparisons with real-world objects that correspond to certain diameters, shown in Table 29. Table 29: Hail Size Comparisons Description Diameter (inches) Pea 0.25 Marble or mothball 0.50 Penny or dime 0.75 Nickel 0.88 Quarter 1.00 Half dollar 1.25 Walnut or ping pong ball 1.50 Golf ball 1.75 Hen's egg 2.00 Tennis ball 2.50 Baseball 2.75 Tea cup 3.00 Grapefruit 4.00 Softball 4.50 Source: NOAA The best available local data for previous hailstorm events in Winthrop are for Suffolk County through the National Centers for Environmental Information. Suffolk County experienced five hail TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 72 events from 2010-2025 shown in Table 39. There were no injuries, deaths, or property damage reported for these hail events. Table 30: Suffolk County Hail Events, 2010-2025 Date Max. Wind Speed (mph) Deaths Injuries Property Damage 5/8/2010 1 0 0 0 6/5/2010 0.75 0 0 0 8/19/2011 0.75 0 0 0 8/19/2011 1 0 0 0 6/8/2012 0.75 0 0 0 7/18/2012 1.25 0 0 0 7/18/2012 0.75 0 0 0 6/17/2013 0.75 0 0 0 8/4/2015 1.5 0 0 0 8/4/2015 2 0 0 0 7/23/2016 0.75 0 0 0 6/13/2017 0.75 0 0 0 6/28/2020 0.75 0 0 0 8/23/2020 0.75 0 0 0 TOTAL 0 0 0 s for Environmental Information *Magnitude refers to diameter of hail stones in inches Hail events are a potential town-wide hazard in Winthrop however the town has not reported any local damage associated with hail. Should a significant hail event occur, the most likely damage would be to vehicles, both town-owned and privately owned, windows, roofs, and other structures, as well as some utility facilities. Damage to vegetation could cause power outages, and damage to some buildings. People outdoors directly exposed to large hail could be at risk of injuries in a severe hail event. Should solar energy facilitates be sited in Winthrop in the future, they could be vulnerable to the impacts of hail. Probability of Future Occurrences Based on the record of previous occurrences, hail events in Winthrop are a Medium frequency event. This hazard may occur once in five years to once in 50 years, with a 2% to 20% chance of occurring each year. WILDFIRE/BRUSHFIRE A brush fire is an uncontrolled fire occurring in a forested, shrub, or grassland area. In the Boston Metro region these fires do not grow to the size of a wildfire as seen more typically in the western U.S. There are three different classes of wildfires: TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 73 • Surface fires are the most common type and burn along the floor of a forest, moving slowly and killing or damaging trees; • Ground fires are usually started by lightning and burn on or below the forest floor; • Crown fires spread rapidly by wind, jumping along the tops of trees. Wildfire season can begin in March and usually ends in late November. The majority of wildfires typically occur in April and May, when most vegetation is void of any appreciable moisture, making them highly flammable. Once "green-up" takes place in late May to early June, the fire danger usually is reduced somewhat. A wildfire differs greatly from other fires by its extensive size, the speed at which it can spread out from its original source, its potential to unexpectedly change direction, and its ability to jump gaps such as roads, rivers and fire breaks. The National Wildfire Coordinating Group (NWCG) classifies the severity of wildfires based on their acreage as follows. Winthrop falls into Class B. • Class A - one-fourth acre or less; • Class B - more than one-fourth acre, but less than 10 acres; • Class C - 10 acres or more, but less than 100 acres; • Class D - 100 acres or more, but less than 300 acres; • Class E - 300 acres or more, but less than 1,000 acres; • Class F - 1,000 acres or more, but less than 5,000 acres; • Class G - 5,000 acres or more (NWCG, 2023). Wildfires can present a hazard where there is the potential for them to spread into developed or inhabited areas, particularly residential areas where sufficient fuel materials might exist to allow the fire to spread into homes. The Wildland Urban Interface (WUI) is the line, area, or zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels. Urban and suburban development in or near wildland vegetation poses a threat of wildfire damages. Potential Wildfire Hazard Areas The Massachusetts State Hazard Mitigation and Climate Action Plan includes a map that depicts statewide fire risk incorporating three risk components: fuel, wildland-urban interface, and topography (Figure 27). The wildland-urban interface reflects communities where housing and vegetation intermingle, and fire can spread from structures to vegetated areas. Winthrop is in an area designated as “no risk” of risk on this map. The Town of Winthrop averages less than five small grass and brush fires each year, with a loss of less than one acre per year due to wild fires. In many years the town does not even have any brush fires and in the years when they do, they are small and quickly contained. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 74 Winthrop is almost completely built out and all new development consists of the redevelopment of existing properties, with no Wildland Urban Interface areas in the community. Outdoor burning is allowed from January to April with a permit from the Fire Department. The Town listed no specific areas of concern for fire-related hazards. F igure 27: Wildfire Risk Areas in Massachusetts Source: MA State Hazard Mitigation and Climate Action Plan, 2018 Although of low severity and frequency, wildfires would be considered a potential Town-wide hazard in Winthrop due to its small size and relatively high density of development, if a wildfire were to occur and not be contained. Probability of Future Occurrence There are no recorded wildfire events for Suff olk County in NOAA’s NCEI database for the last 75 years. Based on a lack of past occurrences, wildfires are of very low frequency events in Winthrop, very unlikely, with minimal examples of historical occurrences. Wildfires and Climate Change As the climate warms, drought and warmer temperatures may increase the risk of wildfire as vegetation dries out and becomes more flammable. Increasing frequency of lightning and increasing damage to trees from pests, can also lead to greater fire risk. The 2022 Assessment cites anticipated forest health degradation from increasing wildfire frequency for the Eastern Inland Region, where Millis is located. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 75 EARTHQUAKES An earthquake is the vibration, sometimes violent, of the earth's surface that follows a release of energy in the earth's crust due to fault fracture and movement. A fault is a fracture in the earth's crust along which two blocks of the crust have slipped with respect to each other. Faults are divided into three main groups, depending on how they move. Normal faults occur in response to pulling or tension: the overlying block moves down the inclined dip of the fault plane. Thrust (reverse) faults occur in response to squeezing or compression: the overlying block moves up the inclined dip of the fault plane. Strike-slip (lateral) faults occur in response to either type of stress; the blocks move horizontally along a vertical fault past one another. Most faulting along spreading zones is normal, along subduction zones is thrust, and along transform faults is strike-slip. The cause of earthquakes in eastern North America is the forces moving the tectonic plates over the surface of the Earth. New England is located in the middle of the North American Plate. One edge of the North American plate is along the west coast where the plate is pushing against the Pacific Ocean plate. The eastern edge of the North American plate is at the middle of the Atlantic Ocean, where the plate is spreading away from the European and African plates. New England’s earthquakes appear to be the result of the cracking of the crustal rocks due to compression as the North American plate is being slowly squeezed by the global plate movements. Damage in an earthquake stems from ground motion, surface faulting, and ground failure in which weak or unstable soils, such as those composed primarily of saturated sand or silts, liquefy. The effects of an earthquake are mitigated by distance and ground materials between the epicenter and a given location. An earthquake in New England affects a much wider area than a similar earthquake in California due to New England’s solid bedrock geology (NESEC). Seismologists use a magnitude scale known as the Richter Scale to express the seismic energy released by each earthquake. The typical effects of earthquakes in various ranges are summarized in Table 31. Table 31: Richter Scale and Effects Richter Magnitudes Earthquake Effects Less than 3.5 Generally, not felt, but recorded 3.5- 5.4 Often felt, but rarely causes damage Under 6.0 At most slight damage to well-designed buildings. Can cause major damage to poorly constructed buildings over small regions. 6.1-6.9 Can be destructive in areas up to about 100 km. across where people live. 7.0- 7.9 Major earthquake. Can cause serious damage over larger areas. 8 or greater Great earthquake. Can cause serious damage in areas several hundred meters across. Source: Nevada Seismological Library (NSL), 2005 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 76 According to the MA Hazard Mitigation Plan, New England experiences an average of five earthquakes per year. From 1668 to 2007, 355 earthquakes were recorded in Massachusetts (NESEC). Most have originated from the La Malbaie fault in Quebec or from the Cape Anne fault located off the coast of Rockport. The region has experienced larger earthquakes, including a magnitude 5.0 earthquake in 1727 and a 6.0 earthquake that struck in 1755 off the coast of Cape Anne. More recently, a pair of damaging earthquakes occurred near Ossipee, NH in 1940, and a 4.0 earthquake centered in Hollis, Maine in October 2012 was felt in the Boston area. Historical records of some of the more significant earthquakes in the region are shown in Table 32. Table 32: Historic Earthquakes in Massachusetts or Surrounding Area Location Date Magnitude MA - Cape Ann 11/10/1727 5 MA - Cape Ann 12/29/1727 NA MA - Cape Ann 2/10/1728 NA MA - Cape Ann 3/30/1729 NA MA - Cape Ann 12/9/1729 NA MA - Cape Ann 2/20/1730 NA MA - Cape Ann 3/9/1730 NA MA – Boston 6/24/1741 NA MA - Cape Ann 6/14/1744 4.7 MA – Salem 7/1/1744 NA MA - Off Cape Ann 11/18/1755 6 MA - Off Cape Cod 11/23/1755 NA MA – Boston 3/12/1761 4.6 MA - Off Cape Cod 2/2/1766 NA MA – Offshore 1/2/1785 5.4 MA - Wareham/Taunton 12/25/1800 NA MA – Woburn 10/5/1817 4.3 MA - Marblehead 8/25/1846 4.3 MA – Brewster 8/8/1847 4.2 MA – Boxford 5/12/1880 NA MA – Newbury 11/7/1907 NA MA - Wareham 4/25/1924 NA MA - Cape Ann 1/7/1925 4 MA - Nantucket 10/25/1965 NA MA – Boston 12/27/74 2.3 MA - Nantucket 4/12/12 4.5 ME – Hollis 10/17/12 4.0 Source: Boston HIRA Winthrop experienced a small, 2.3 magnitude earthquake located 2 km from it on April 10, 2009. There was no data that indicated any impacts associated with this event. On October 16, TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 77 1963 an earthquake occurred in eastern Massachusetts of magnitude 6.3 that caused a window to crack in Winthrop. (USGS) One measure of earthquake extent is ground motion, which is measured as maximum peak horizontal acceleration, expressed as a percentage of gravity (1 g). The range of peak ground acceleration in Massachusetts is from 10g to 20g, with a 2% probability of exceedance in 50 years, as shown in Figure 28. Winthrop is in the middle part of the range for Massachusetts making it a moderately low area of earthquake risk within the state, although the state as a whole is considered to have a low risk of earthquakes compared to the rest of the country. Although New England has not experienced a damaging earthquake since 1755, seismologists state that a serious earthquake occurrence is possible. There are five seismological faults in Massachusetts, but there is no discernible pattern of previous earthquakes along these fault lines. Earthquakes occur without warning and may be followed by aftershocks. Most older buildings and infrastructure were constructed without specific earthquake resistant design features. Town officials noted it would be useful to map the Cape Ann fault to increase public awareness of that significant earthquakes have occurred in the North Shore area historically, that the Town could be subject to earthquake damage and that it should be included in capital facilities planning. Figure 28: Massachusetts Earthquake Probability Map Source: 2018 SHMCAP Another factor related to earthquake hazards in the greater Boston area is the process of liquefaction, which can exacerbate the damage from an earthquake. Liquefaction may occur in areas of soft clays or filled land, which are found in the northern portion of Winthrop (Figure 29). During an earthquake event these soils may become unstable, effectively liquefying, destabilizing the buildings above and potentially leading to ruptured utilities, and other related impacts. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 78 Figure 29 - Boston Study Region Liquefaction Potential Source: Baise, Laurie G., Rebecca B. Higgins ; and Charles M. Brankman, Tufts University Earthquakes are a hazard with multiple impacts beyond the obvious building collapse. Buildings may suffer structural damage which may or may not be readily apparent. Earthquakes can cause major damage to roadways, making emergency response difficult. Water lines and gas lines can break, causing flooding and fires. Another potential vulnerability is equipment within structures. For example, a hospital may be structurally engineered to withstand an earthquake, but if the equipment inside the building is not properly secured, the operations at the hospital could be severely impacted during an earthquake. Earthquakes can also trigger landslides. Earthquakes are a potential Town-wide hazard in Winthrop. Although new construction under the current Massachusetts Building Code will be built to higher seismic standards, there are older structures in Winthrop that pre-date the most recent building code. Potential earthquake damages to Winthrop have been estimated using HAZUS-MH. Total building damages, including business interruption losses are estimated at $375 million for a 5.0 magnitude earthquake and $2.1 billion million for a 7.0 magnitude earthquake. Other potential impacts are detailed in Table 45. In addition, information on geologic hazards in Winthrop can be found on Map 4 in Appendix A. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 79 Probability of Future Occurrence There are several ways the probability of future occurrences of earthquakes has been estimated. According to the Boston College Weston Observatory, in most parts of New England there is a one in ten chance that a potentially damaging earthquake will occur in a 50-year time period. Earthquakes in Winthrop are a low frequency event as defined by the Resilient MA Plan. This hazard is likely to occur at least once by the end of the century; anticipated every 100 years. LANDSLIDES According to the USGS, “The term landslide includes a wide range of ground movement, such as rock falls, deep failure of slopes, and shallow debris flows. Although gravity acting on an over steepened slope is the primary reason for a landslide, there are other contributing factors.” Among the contributing factors are erosion by rivers or ocean waves over steepened slopes; rock and soil slopes weakened through saturation by snowmelt or heavy rains; earthquakes create stresses that make weak slopes fail; and excess weight from accumulation of rain or snow, and stockpiling of rock or ore, from waste piles, or from man-made structures. Landslides can result from human activities that destabilize an area or can occur as a secondary impact from another natural hazard such as flooding. In addition to structural damage to buildings and the blockage of transportation corridors, landslides can lead to sedimentation of water bodies. Typically, a landslide occurs when the condition of a slope changes from stable to unstable. Natural precipitation such as heavy snow accumulation, torrential rain and run-off may saturate soil creating instability enough to contribute to a landslide. The lack of vegetation and root structure that stabilizes soil can destabilize hilly terrain. In Massachusetts, according to the SHMCAP, the most common cause of landslides are geologic conditions combined with steep slopes and/or heavy rains. Landslides associated with heavy rains typically occur on steep slopes with permeable soils underlain by till or bedrock. There is no universally accepted measure of landslide extent, but it has been represented as a measure of destructiveness. Table 33 summarizes the estimated intensity for a range of landslides. For a given landslide volume, fast moving rock falls have the highest intensity while slow moving landslides have the lowest intensity. Table 33: Landslide Volume and Velocity Estimated Volume Expected Landslide Velocity (m 3) Fast moving landslide (Rock fall) Rapid moving landslide (Debris flow) Slow moving landslide (Slide) <0.001 Slight intensity <0.5 Medium intensity >0.5 High intensity <500 High intensity Slight intensity 500-10,000 High intensity Medium intensity Slight intensity 10,000 – 50,000 Very high intensity High intensity Medium intensity >500,000 Very high intensity High intensity >>500,000 Very high intensity A Geomorphological Approach to the Estimation of Landslide Hazards and Risks in Umbria, Central Italy , M. Cardinali et al, 2002 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 80 The SHMCAP utilized data from the MA Department of Transportation from 1986 to 2006 to estimate that, on average, roughly one to three known landslides have occurred each year in the state. A slope stability map published by the MA Geological Survey and UMass-Amherst indicates that the most significant risk of landslide is in western Massachusetts. The entire Town has been classified as having a low incidence risk for landslides, less than 1.5 % of the area is involved in land sliding. (Map 4, Appendix A). The best available data on previous incidences of landslides in Winthrop is for Suffolk County through NOAA’s National Center For Environmental Information. For the 75 years from 1950 to 2025, no landslides were recorded for Suffolk County. According to the Town, no acreage in Winthrop has historically been lost to landslides, and there is no record of any damage caused by landslides. Should a landslide occur in the future, the type and degree of impacts would be highly localized, and the Town’s vulnerabilities could include damage to structures, damage to transportation and other infrastructure, and localized road closures. Injuries and casualties, while possible, would be unlikely given the low extent and impact of landslides in Winthrop. Potential damages would depend on how many properties were affected. Given the relatively high assessed value of property in Winthrop, damages affecting a single residence could exceed $500,000, and damages affecting several homes or business properties could theoretically exceed several million dollars. However, there are no records of such landslide damages in Winthrop. Probability of Future Occurrences Although the Resilient MA Plan classifies landslides as high likelihood events statewide, based on past occurrences and topographic conditions in Winthrop, landslides are very low frequency events in the town. This hazard is very unlikely to occur and there are minimal examples of historical occurrences. Climate Change and Landslides Changes in precipitation may increase the chance of landslides, as extreme rain events could result in more frequent saturated soils which are conducive to landslides. Drought may also increase the likelihood of landslides if loss of vegetation decreases soil stability. EXTREME TEMPERATURE HAZARDS AVERAGE AND EXTREME TEMPERATURES Extreme temperatures occur when either high temperature or low temperatures relative to average local temperatures occur. These can occur for brief periods of time and be acute, or they TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 81 can occur over long periods of time where there is prolonged period of excessively hot or cold weather. Winthrop has four well-defined seasons. The seasons have several defining factors, with temperature one of the most significant. Extreme temperatures can be defined as those which are far outside of the normal seasonal ranges for Massachusetts. The average seasonal temperatures for Massachusetts are: Winter (Dec-Feb) Average = 31.8°F and Summer (Jun-Aug) Average = 71°F. The lowest recorded temperature was -19°F in 1934. The highest recorded temperature for Winthrop was 104°F in 1911, and the lowest recorded temperature was -19°F in 1934. Extreme temperatures are a town-wide hazard in Winthrop. EXTREME HEAT While a heat wave for Massachusetts is defined as three or more consecutive days above 90°F, another measure used for identifying extreme heat events is through a Heat Advisory from the NWS. These advisories are issued when the heat index (Figure 30) is forecast to exceed 100- degree Fahrenheit (F) for 2 or more hours; an excessive heat advisory is issued if forecast predicts the temperature to rise above105 degree F. Figure 30 Heat Index Chart Source: National Weather Service The best available data on past occurrences of extreme heat events is from NOAA’s National Centers for Environmental Information (NCEI) for Suffolk County, which includes Winthrop. The NCEI records indicate that since 2010, there have been six excessive heat events recorded, with no reported death, no injuries, and no property damage (Table 34). The hottest single day temperature recorded in Eastern Massachusetts by the National Weather Service’s Norton/Boston regional office was 104 degrees (F) on July 4, 1911. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 82 Table 34: Suffolk County Extreme Heat Occurrences 2000 - 2025 Date Deaths Injuries Damages 12/17/2000 0 0 0 5/3/2001 0 0 0 5/4/2001 0 0 0 5/12/2001 0 0 0 7/22/2011 0 0 0 7/3/2018 0 0 0 Source: NOAA, National Centers for Environmental Information Extreme heat poses a potentially greater risk to the elderly, children, and people with certain medical conditions. However, even young and healthy individuals can succumb to heat if they participate in strenuous physical activities during hot weather. Older adults are often at elevated risk due to a high prevalence of pre-existing and chronic conditions; in Winthrop, approximately 20.2% of the population is over age 65. People who live in older housing stock and in housing without air conditioning have increased vulnerability to heat-related illnesses. Areas with less shade and darker surfaces (pavement and roofs) will experience even hotter temperatures; these surfaces absorb heat during the day and release it in the evening, keeping nighttime temperatures warmer as well. Map 9 in Appendix A displays areas that are among the hottest 5% of land in the MAPC region based on land surface temperature derived from satellite imagery on July 13, 2016, when the high temperature at Logan Airport was 92 ° F. There are t hree “hot spot” areas in Winthrop, the largest in the Winthrop Center area, as shown on Map 9 . Hot summer days can worsen air pollution. With increased extreme heat, urban areas are likely to experience more days that fail to meet air quality standards. Power failures are more likely to occur during heat waves, affecting the ability of residents to remain cool. Individuals with pre- existing conditions and those who require electric medical equipment may be at increased risk during a power outage. Key health risks of extreme heat are summarized in Figure 31. Figure 31 Health Risks Associated with Extreme Heat Source: Killer Heat in the United States, Union of Concerned Scientists TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 83 The 2018 SHMCAP identifies ecosystems that are expected to be particularly vulnerable to warming temperatures. These include cold-water fisheries, vernal pools, spruce-fir forests, northern hardwood forests (Maple, Beach, Birch), Hemlock forests, and urban forests (due to heat island impacts). Other Impacts on natural resources include a longer growing season and northern migration of plants and animals, including invasive species. Heat Waves While the number of 90F+ days per year is a broad indication of extreme temperatures, an indicator that relates more directly to public health impacts is the occurrence of multiple-day heat waves, defined at three or more consecutive days with high temperatures 90F or higher. The summer of 2021 was an example of this, as shown in Figure 32. Figure 32: Summer 2021 Temperatures, Boston Area Source: NOAA The summer of 2021 was particularly hot, with four heat waves.. Two of these lasted for five days, one lasted four days, and one lasted three days. Overall, there were 24 days 90F or more, 17 of which occurred during the four heat waves. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 84 Extreme Heat and Climate Change The 2022 MA Climate Change Assessment includes projections of climate-driven future increases in average temperature and in the number of extreme heat days. The assessment also highlights the following climate impacts related to temperatures. The number of days per year over 90°F is projected to increase over the next several decades, with the amount of increase depending on whether a lower or higher greenhouse gas emission (GHG) scenario is met. By 2070 the difference between the low and high GHG emissions scenarios could be a doubling of the annual number of 90°F days, from 47 to 90 days. By then, it is possible that the entire summer will be marked by temperatures above 90°F (Figure 33). This compares to the current average of 10 to 15 days per year. With changes of this magnitude, over the course of the next several decades, the Massachusetts climate could become more similar to areas well to the south of New England (Figure 34). Figure 33: Comparison of Days Above 90F for Low and High Emission Scenarios Source: Somerville Climate Change Vulnerability Assessment Probability of Future Occurrences Extreme heat events are classified as very high frequency events as defined by the Resilient MA Plan. Extreme temperature events are almost certain to occur multiple times a year. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 85 Warmer temperatures and more frequent heat waves are connected to impaired human health, increased droughts, reduced agriculture yields, species range shifts, and damaged infrastructure. • By 2030, the summer mean temperature could increase by 3.6°F from the historical period (1950-2013), worsening stress on electric transmission and utility distribution infrastructure. • By 2070, there could be 58 fewer days below freezing, increasing the chance of ticks overwintering and reducing winter recreation opportunities. • Increase in vector borne diseases and bacterial infections, including West Nile Virus and Lyme disease due to more favorable conditions for ticks and mosquitoes. • Damage to electric transmission and utility distribution infrastructure associated with heat stress • Damage to rails and loss of rail/transit service, including flooding and track buckling during high heat events. • Reduced ability to work, particularly for outdoor workers during extreme heat, as well as commute delays due to damaged infrastructure. • Freshwater ecosystem degradation due to warming waters. • Forest health degradation from warming temperatures and increasing pest occurrence EXTREME COLD Extreme cold is relative to the normal climatic lows in a region. Temperatures that drop decidedly below normal and wind speeds that increase can cause harmful wind-chill factors. The severity of extreme cold temperature is typically measured using the Wind Chill Temperature Index, which is provided by the National Weather Service (NWS). The wind chill is the apparent temperature felt on exposed skin due to the combination of air temperature and wind speed. The index is provided in Figure 35. A Wind Chill warning is issued when the Wind Chill Index is forecast to fall below -25 degrees F for at least 3 hours. Figure 34: Temperature Scenarios Source: Union of Concerned Scientists (2007) TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 86 Figure 35. Wind Chill Temperature Index and Frostbite Risk Source: National Weather Service The best available data on past occurrences of extreme cold events are from NOAA’s National Centers for Environmental Information (NCEI) for Suffolk County, which includes the Town of Winthrop. There were three extreme cold events recorded by NCEI since 2005 (Table 35), which caused one deaths, no injuries, and no property damage. The coldest single day temperature recorded in Eastern Massachusetts by the National Weather Service’s Norton/Boston regional office was -18 degrees (F) on February 9, 1933. Table 35: Suffolk County Extreme Cold Occurrences 2005 -2025 Date Deaths Injuries Damages 2/3/2007 1 0 0 2/16/2015 0 0 0 2/14/2016 0 0 0 Source: NOAA, National Centers for Environmental Information Extreme cold is a dangerous situation that can result in health emergencies for susceptible people, such as those without shelter or who are stranded or who live in homes that are poorly insulated or without heat. The greatest vulnerability to the Town would be a power outage during a winter storm, which could temporarily leave many residents without heat. The elderly and people with disabilities are often most vulnerable. In Winthrop, 20.2% of residents are 65 years old and over, and 29.8% have a disability. Probability of Future Occurrences Extreme cold events are classified as very high frequency events as defined by the Resilient MA Plan. Extreme temperature events are almost certain to occur multiple times a year. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 87 DROUGHT HAZARDS Drought is a temporary irregularity in precipitation and differs from aridity since the latter is restricted to low rainfall regions and is a permanent feature of climate. Drought is a period characterized by long durations of below normal precipitation. Drought conditions occur in virtually all climatic zones, yet its characteristics vary significantly from one region to another, since it is relative to the normal precipitation in that region. Drought can affect agriculture, water supply, aquatic ecology, wildlife, and plant life. In Massachusetts, droughts are caused by the prevalence of dry northern continental air and a decrease in coastal- and tropical-cyclone activity. During the 1960's, a cool drought occurred because dry air from the north caused lower temperatures in the spring and summer of 1962-65. The northerly winds drove frontal systems to sea along the Southeast Coast and prevented the Northeastern States from receiving the normal sources of moisture (see Figure 36). This is considered the drought of record in Massachusetts. Figure 36: Principal Sources and Pattern of Moisture Delivery to Massachusetts U.S. Geological Survey Water-Supply Paper 2375, National Water Summary 1988-89 Average annual precipitation in Massachusetts is 44 inches per year, with approximately 3-to-4- inch average amounts for each month of the year. Regional monthly precipitation ranges from zero to 17 inches. Statewide annual precipitation ranges from 30 to 61 inches. Thus, in the driest calendar year (1965), the statewide precipitation total of 30 inches was 68 percent of average. Although Massachusetts is relatively small, it has a number of distinct regions that experience significantly different weather patterns and react differently to the amounts of precipitation they receive. The DCR precipitation index divides the state into seven regions: Western, Central, TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 88 Connecticut River Valley, Northeast, Southeast, Cape Cod, and Islands. Marlborough is located in the Northeast Region. In Marlborough drought is a potential city-wide hazard. The Massachusetts Drought Management Plan was revised in 2019 to change the state’s classification of droughts by establishing four levels to characterize drought severity beyond normal conditions: • Level 0-Normal Conditions (no drought) • Level 1-Mild Drought (formerly Advisory) • Level 2-Significant Drought (formerly Watch) • Level 3-Critical Drought (formerly Warning) • Level 4-Emergency Drought (formerly Emergency) The Massachusetts drought levels are shown in comparison to the U.S. Drought Monitor levels in Table 36 . The two sets of drought indices are similar, but Massachusetts combines the USDM’s level D2 and D3 into one category, Critical Droughts. Table 36: US Drought Monitor Compared to MA Statewide Drought Levels Source: Massachusetts Drought Management Plan, 2019 These levels are based on the conditions of natural resources and provide information on the current status of water resources. As dry conditions can have a range of different impacts, a number of drought indices are available to assess these impacts. Massachusetts uses a multi-index system that takes advantage of several of these indices to determine the severity of a given drought or extended period of dry conditions. Drought level is determined monthly based on the number of indices which have reached a given drought level. Drought levels are declared on a regional basis for each of seven regions in Massachusetts. County by county or watershed-specific determinations may also be made. A determination of drought level is based on seven indices: 1. The Standardized Precipitation Index (SPI) reflects soil moisture and precipitation. 2. Crop Moisture Index: (CMI) reflects soil moisture conditions for agriculture. 3. Keetch Byram Drought Index (KBDI) is designed for fire potential assessment. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 89 4. The Precipitation Index is a comparison of measured precipitation amounts to historic normal precipitation. 5. The Groundwater Level Index is based on the number of consecutive month’s groundwater levels are below normal (lowest 25% of period of record). 6. The Stream flow Index is based on the number of consecutive months that stream flow levels are below normal (lowest 25% of period of record). 7. The Reservoir Index is based on the water levels of small, medium and large index reservoirs across the state, relative to normal conditions for each month. Table 37 shows the range of values for each of the indices associated with the drought levels. Because drought tends to be a regional natural hazard, this plan references state data as the best available data for previous drought occurrences. Determinations regarding the end of a drought or reduction of a drought level focus on precipitation and groundwater levels. These factors have the greatest long-term impact on stream flow, water supply, reservoir levels, soil moisture, and forest fire potential. Table 37: Indices Values Corresponding to Drought Index Severity Levels Source: Massachusetts Drought Management Plan, 2019 The drought levels provide a framework from which to take actions to assess, communicate, and respond to drought conditions. Drought levels are used to coordinate both state agency and local response to drought situations. Water restrictions might be appropriate at the significant drought stage, depending on the capacity of each individual water supply system. A critical drought level indicates a severe situation and the possibility that a drought emergency may be necessary. A drought emergency is one in which mandatory water restrictions or use of emergency supplies is necessary. Previous Occurrences Because drought tends to be a regional natural hazard, the best available date on previous drought occurrences is state-wide data, summarized below. The Executive Office of Energy and TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 90 Environment ’s Drought Management Task Force also provides information on historic drought status for each drought level in Massachusetts. That information is summarized below. Mild Drought/Advisory 2001, 2002, 2007, 2014, 2016, 2017, 2020, 2021, 2022 Significant Drought/Watch 2002, 2016, 2017, 2020, 2021, 2022 Critical Drought/Warning 2016, 2017, 2020, 2022 Emergency Drought/Emergency None Figure 37 shows the frequency and extent of drought events in Massachusetts since the year 2001. The graphic clearly shows an increase in severe drought events in the most recent years of this 21-year period. In just the last seven years there have been four droughts at the extreme level in Massachusetts, in 2016, 2017. 2020, and 2022. Figure 37: Weeks of Extreme Drought (2001-2022) Source: A summary of Massachusetts long term historic drought events from 1879 to 2019 is shown in Table 30. This table was prepared for the 2019 Massachusetts Drought Management Plan, so it does not include the more recent droughts of 2020 (Level 3) and 2021(Level 2). TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 91 Table 38 - Chronology of major droughts in Massachusetts since 1879 Source: Massachusetts Drought Management Plan, 2019 As shown in Figure 38, the geographic extent of droughts from 2001 to 2017 varied greatly in different parts of the state. Winthrop experienced between 26 and 36 weeks of severe drought between 2001 and 2017. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 92 Figure 38: Weeks of Extreme Drought Mapped by Region (2001-2017) Source: SHMCAP 2018 Figure 39 shows the geographic extent of each of the droughts in 2016, 2020, and 2021. The drought of 2016 was the worst one since 1985, with more than half of the state reaching the Extreme Drought stage for several months. This was followed by another drought four years later in 2020, which was the most severe in Southeastern Massachusetts. Finally, in the early spring of 2021 a third, milder, drought was declared. By the summer of 2021 conditions in the northeast region improved. Figure 39: Recent Massachusetts Drought Events (2016-2021) Source: US Drought Monitor, 2016-2021 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 93 Potential Drought Vulnerability The entire Town of Winthrop is potentially vulnerable to the impacts of drought. Under a severe long-term drought, Winthrop could be vulnerable to restrictions on water supply. However, the Town’s water supply comes from the Massachusetts Water Resources Authority, which operates two large reservoirs, Quabbin and Wachusett, which have multiple years of storage available to offset drought impacts. The system was able to meet water demands even in the drought of record in the 1960s. It’s possible the MWRA sys tem could be impacted by a more severe multi- year drought, but such a drought has not occurred since records have been kept. Potential damages of a severe drought could include losses of landscaped areas on private properties as well as public facilities if outdoor watering is severely restricted. Losses could also include potential loss of business revenues if water supplies were severely restricted for a prolonged period. As this hazard of this severity has never occurred in Winthrop, there are no data or estimates of potential damages, but under a severe drought scenario it would be reasonable to expect a range of potential damages up to several million dollars due to business interruption. Probability of Future Occurrence The SHMCAP, using data collected since 1850, calculates that statewide there is a 1% chance of being in a drought emergency in any given month. For drought warning and watch levels, the chance is 2% and 8% respectively in any given month. See Table 391 for more information. Table 39: Frequency of Massachusetts Drought Levels Drought Level Frequency Since 1850 Probability in a Given Month Drought Emergency 5 occurrences 1% chance Drought Warning 5 occurrences 2% chance Drought Watch 46 occurrences 8% chance Source: 2018 SHMCAP Droughts are a medium frequency event as defined by the Resilient MA Plan, likely to occur at least once every 50 years (two or more occurrences in the next century) Droughts And Climate Change Droughts are projected to increase in frequency and intensity in the summer and fall as weather patterns change. Factors contributing to this include increasing evaporation as a result of warmer weather, earlier snow melt, and more extreme weather patterns. Information from the 2022 Massachusetts Climate Change Assessment related to drought is included in the “Climate Change Observations and Projections” section of this report. Additionally, the 2022 Assessment highlights the following drought-related impacts to the Eastern Inland region where Marlborough is located: TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 94 • Freshwater ecosystem degradation due to drought and other impacts • Increased contaminant concentrations in freshwater during drought conditions • Loss of tree cover due to drought and other impacts TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 95 LAND USE AND DEVELOPMENT TRENDS WINTHROP LAND USE Land use mapping is available for communities statewide from Mass GIS. Map 2 in Appendix A shows the land use map for Winthrop, and Table 40 shows the acreage and percentage of land in 20 categories. The largest single land use category by far in Winthrop is residential, with 712.2 acres 48.9% of the Town in the high density and multifamily residential categories combined. The next largest land use is transportation, at 19.4 acres or 13.7% of the Town, followed by saltwater beach at 9.2% and saltwater wetlands at 7.2%, underscoring the Town’s coastal location. Commercial and industrial uses have a relatively small area of 73.3 acres, or 5.0% of the total Table 40: Winthrop Land Use Land Type Acres Percent Forest 2.10 0.14 Wetland 6.47 0.44 Open Land 42.14 2.89 Participation Recreation 43.17 2.96 Multifamily Residential 371.95 25.53 High Density Residential 340.25 23.35 Saltwater Wetland 106.93 7.34 Commercial 71.58 4.91 Industrial 2.19 0.15 Transportation 199.45 13.69 Waste Disposal 2.32 0.16 Water 7.87 0.54 Saltwater Beach 133.70 9.18 Golf Course 52.04 3.57 Marina 16.90 1.16 Urban Public 34.96 2.40 Cemetery 15.77 1.08 Nursery 0.27 0.02 Forested Wetland 0.23 .016 Brush land/Succession 6.62 0.45 TOTAL 1,456.91 100 Source: MA GIS Land Use Statistics ECONOMIC ELEMENTS The economy of Winthrop employed 10,132 people in 2023., the largest employment sectors were Health Care & Social Assistance (1,299 people), Professional, Scientific, & Technical Services (1,085 people), and Educational Services (956 people). The breakdown of employment in 19 categories is shown in Table 41. Figure 40 shows the trends in employment over the period 2002 to 2022. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 96 Table 41 Winthrop Employment by Category, 2023 Industry Workforce Percent Agriculture, Forestry, Fishing & Hunting 15 0.15% Mining, Quarrying, & Oil & Gas Extraction 9 0.09% Construction 524 5.17% Manufacturing 695 6.86% Wholesale Trade 256 2.53% Retail Trade 573 5.66% Transportation & Warehousing 901 8.89% Utilities 20 0.20% Information 411 4.06% Finance & Insurance 679 6.70% Real Estate & Rental & Leasing 202 1.99% Professional, Scientific, & Technical Services 1085 10.71% Administrative & Support & Waste Management 462 4.56% Educational Services 956 9.44% Health Care & Social Assistance 1299 12.82% Arts, Entertainment, & Recreation 357 3.52% Accommodation & Food Services 688 6.79% Other Services, Except Public Administration 437 4.31% Public Administration 563 5.56% TOTAL 10,132 Source: U.S. Census Bureau, ACS 5-year Estimate Figure 40 Winthrop Employment by Category, 2023 Source: Executive MA Office of Labor and Workforce Development,-2023 TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 97 Although primarily a residential community, the Town features several unique business areas: the Shirley Street Business District, the Highlands District, Magee's Corner District, and the Winthrop Center District. The Town has a modestly vibrant business community, however, in recent decades large shopping malls in the nearby North Shore region began to impact businesses in Winthrop, In 2017 the Town undertook the Winthrop Center Business District to focus on the key center of business in the Town. The study assesses the strengths and challenges facing local businesses, and provides recommendations to support and revitalize the district. The plan also notes concerns for potential flooding risks. As with the predominantly residential areas of Winthrop, a portion of the Winthrop Center business district faces flooding risks. An area along the western side of the district is located with the FEMA AE mapped flood zone (Figure 41). The Master Plan concludes that “ As a community surrounded by water, Winthrop must be particularly vigilant in adhering to resiliency standards that address threats pose by sea level rise.” Figure 41 Winthrop Center Business District Source: Winthrop Center Business District Master Plan, 2017 DEVELOPMENT TRENDS With limited land area, Winthrop is largely built out, so new growth in the Town consists of redevelopment of existing developed sites. New developments in the MAPC region are tracked on Mass Builds. The following developments shown in Table 42 are listed in Mass Builds as completed since the previous Hazard Mitigation Plan in 2015. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 98 Table 42: Winthrop Developments Completed Since 2015 Site# DEVELOPMENT DEVELOPMENT TYPE Res. Units STATUS A Temple Israel 40 unit assisted living development 40 Completed C Belle Isle Bridge Bridge repair under the MA Accelerated Bridge Replacement program, elevated one foot in height --- Completed D 142 Pleasant St Conversion of former nursing home into condominiums 16 Completed E Winthrop Hospital Pizzuti Development Age restricted 74 Completed F Dalrymple School redevelopment Renovation of abandoned school into affordable age restricted housing. 27 Completed G 60 Hermon Street Reuse of former religious facility, 5 units 5 Completed H 15-17 Walden St Conversion of commercial property into condominiums 16 Completed I 413-415 Shirley St. Redevelopment for 25 residential units 25 Completed J 5 Fremont Street Redevelopment of office building into mixed-use residential and commercial. Existing offices will remain. 22 Completed K 10-26 Somerset Ave Projected 30 residential units 30 Completed L 20 Main St Restoration to the existing structure for a mixed-use commercial development. --- projected Source: Mass Builds CRITCAL FACILITIES Critical Infrastructure in Hazard Areas Critical infrastructure includes three categories of facilities that are important to the Town: • Critical Infrastructure such as water and wastewater pumps, communications, • Facilities that provide utility for disaster response and evacuation such as emergency operations centers, fire and police stations, public works facilities, • Facilities where additional assistance might be needed during an emergency, such as nursing homes, elderly housing, schools, day care centers, etc.. TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 99 The Winthrop Hazard Mitigation Team updated the Critical Facilities inventory and map from the previous Hazard Mitigation Plan, adding additional facilities to the list and updating existing facilities as needed. The Team identified re are xx Critical Facilities, xx of which were newly added sites for this plan update. These are listed in Table 43x and are shown on the maps in Appendix A. Table 43 – Winthrop Critical Facilities MAP# FACILITY NAME ADDRESS FACILITY TYPE 1 11 - 54 Overlook Drive 11 - 54 Overlook Drive Elder Housing 2 Atlantis Marina 550 Pleasant St Marina 3 Beach Fire Station 416 Shirley St. Fire Station 4 Belle Isle Marsh Water Feature 5 Bright Beginnings Learning Center 89 Veterans Road Child Care 7 CVS 3 Woodside Ave. Pharmacy 8 Cell Tower At Expert Auto 120 Shirly Street Communication Tower 9 Cell Tower At Fellows Hall 198 Winthrop Street Communication Tower 10 Cell Tower At St. Johns the Evangelist Church 320 Winthrop Street Communication Tower 11 Cell Tower At United Methodist Church 217 Winthrop Street Communication Tower 12 Arthur Cummings School 40 Hermon St School 13 Children's Corner Preschool 210 Pauline St. Child Care 14 Concrete Seawall Seal Harbor Condo Flood Protection 15 Concrete Seawall Revere Street Flood Protection 16 Cottage Park Yacht Club 76 Orlando Ave Marina 17 Crystal Cove Marina 529 Shirley St Marina 18 Deer Island Waste Water Treatment 190 Tafts Ave Waste Water Treatment 19 E B Newton 45 Pauline Street School 21 Fire Headquarters 40 Pauline St. Fire Station 22 For Kids Only Extended Day in Parish School 233 Winthrop Child Care 23 Gorman/ Fort Banks Elementary School 101 Kennedy Road School 24 Golden Drive 1 - 22 Golden Drive Special Needs 26 John Clark House (N Suffolk Mental Health) 152 Pleasant St Assisted Living 27 King Gardens 2 Kennedy Road Elder Housing 28 Lewis Lake Tidal Gate Washington Ave Flood Prevention 29 Lodge Elks Marina 191 Washington Ave Marina 30 Loring Rd Boat Ramp Loring Rd Boat Ramp TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 100 MAP# FACILITY NAME ADDRESS FACILITY TYPE 31 Memorial Auditorium 149 Pauline Street School 32 Mrs. Marley's Nursery School 415 Shirley Street Child Care 33 North Suffolk Mental Health 225 Pleasant St. Special Needs 34 North Suffolk Mental Health 133 Morton St. Assisted Living 35 North Suffolk Mental Health 138 Morton St. Assisted Living 36 North Suffolk Mental Health 11 Pearl Ave Assisted Living 37 Old Town Garage 233R Winthrop Street Kennel 38 Pico Sewer Pump Station Pico Ave Sewer Pump Station 39 Pier Off Court Rd Recreation 40 Private Pier Off Court Rd Recreation 41 Pleasant Court Sewer Pump Station Pleasant Ct Sewer Pump Station 42 Pleasant Park Yacht Club 562 Pleasant St Marina 43 Pleasant Times Day Care 65 Putnam St Child Care 44 Point Shirley Association 1032 Shirley St Shelter 45 Police Station 3 Metcalf Sq. Police Station 46 Post Office 5 Michaels Mall Post Office 47 Public Landing 700 Shirley St Water Access 48 Public Safety Communication Tower Faun Bar Ave Communication Tower 49 Recreation Center 45 Pauline St After School Program 50 Revere St Sewer Pump Station Revere St Sewer Pump Station 51 Rice’s Wharf 585R Shirley St Marina 54 Skatting Rink Pauline St. Place of Assembly 55 St John The Evangelist Church 320 Winthrop St Church 56 St John's Episcopal Church 225 Bowdoin St Church 57 Stone Breakwater Winthrop Shore Dr. Flood Prevention 58 Stone Revetment Forth Heath Revetment 59 Stone Revetment Winthrop Shore Dr. Revetment 60 Stone Revetment Grovers Ave. Revetment 61 Stone Revetment Winthrop Highlands Revetment 62 Temple Tifereth Israel 93 Veteran's Rd Church 64 Town Hall 1 Metcalf Sq. Municipal 65 Union Congregational Church 22 Tewksbury St Church 66 United Methodist Church 217 Winthrop St Church TOWN OF WINTHROP HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 101 MAP# FACILITY NAME ADDRESS FACILITY TYPE 67 Viking Gardens 107 Putnam St. Elder Housing 68 Winthrop Country Day Learning Ctr. 96 Winthrop St. Child Care 69 Winthrop DPW Building 100 Kennedy Rd. Municipal 70 Winthrop Traffic Control Point Main St && Revere St Traffic Control Point 70 Winthrop EOC 30 Herman St Emergency Operations Center 71 Winthrop Traffic Control Point Shirley St & Washington Ave Traffic Control Point 73 Yirrell Beach Off Shirley St Water Feature 74 Winthrop Middle School 151 Pauline St School 75 Winthrop Senior Center 35 Harvard St Senior Center 76 Winthrop Place 26 Sturgis St Elder Housing 77 Winthrop Middle/High School 400 Main Street School 78 Winthrop Traffic Control Point Shirley St && Veterans Rd Traffic Control Point 80 Winthrop Traffic Control Point Main St && Pleasant St. Traffic Control Point 81 Winthrop Market Place 35 Revere Street Grocery Store 82 Winthrop Traffic Control Point Revere St && Shirley St Traffic Control Point 83 Winthrop Traffic Control Point Shore Drive && Beach Rd Traffic Control Point 85 Winthrop Library 2 Metcalf Sq Library 86 Winthrop Reservation Winthrop Shore Drive Water Feature 87 Winthrop Traffic Control Point Revere St && Crest Ave Traffic Control Point 88 Winthrop Water Storage Tank Faun Bar Ave Water Storage Tank 89 Winthrop Yacht Club 649 Shirley St Marina 90 Winthrop Traffic Control Point Winthrop Parkway & Revere St Traffic Control Point 91 Private Pier off 227 Court Rd Pier 92 Private Pier 68 Johnson Ave Pier 93 Tafts Avenue TCP Tafts and Eliott Traffic Control Point 94 Belle Isle Bridge Main Street Bridge 95 Pressure Reducing Valve Station Revere Street Water Facility 96 Power Substation Argile St Power Substation 97 Power Substation Winthrop Street Power Substation Source: Winthrop Hazard Mitigation Team TOWN OF ESSEX HAZARD MITIGATION PLAN DRAFT 2025 UPDATE 102 VULNERABILITY ASSESSMENT The purpose of the vulnerability assessment is to estimate the extent of potential damages from natural hazards of varying types and intensities. A vulnerability assessment and estimation of damages was performed for hurricanes, earthquakes, and flooding. The methodology used for hurricanes and earthquakes was the HAZUS-MH software. The methodology for flooding was developed specifically to address the issue in many of the communities where flooding was not solely related to location within a floodplain. Introduction to HAZUS-MH HAZUS- MH (multiple-hazards) is a computer program developed by FEMA to estimate losses due to a variety of natural hazards. The following overview of HAZUS-MH is taken from the FEMA website. For more information on the HAZUS-MH software, go to http://www.fema.gov/plan/prevent/hazus/index.shtm “HAZUS -MH is a nationally applicable standardized methodology and software program that contains models for estimating potential losses from earthquakes, floods,
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related records
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