Resilient Winthrop: Designing Coastal Community Infrastructure for Climate Change

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Resilient Winthrop 
Designing Coastal Community 
Infrastructure for Climate Change 
July 27, 2017

Prepared by 
Town of Winthrop 
1 Metcalf Square 
Winthrop, MA 02152 
Massachusetts Office 
of Coastal Zone 
Management 
251 Causeway Street 
Boston, MA 02114 
Stantec 
226 Causeway Street, 6th Fl. 
Boston, MA 02114 
Woods Hole Group 
81 Technology Park Drive 
East Falmouth, MA 02536 
Financial assistance provided by the Executive Office of Energy & Environmental Affairs (EEA), through the 
Massachusetts Office of Coastal Zone Management (CZM), under the FY17 Coastal Community Resilience Grant 
Program. This program provides financial and technical resources to advance new and innovative local efforts to 
increase awareness of climate impacts, identify vulnerabilities, and implement measures to increase community 
resilience.

a 
Resilient Winthrop 
Designing Coastal Community 
Infrastructure for Climate Change 
Contents 
Executive Summary 
V ulnerability Assessment Purpose 
V ulnerability Assessment Process 
Future Areas of Coastal Flooding 
Critical Public Infrastructure 
Likely Flood Areas in Winthrop 
Critical Public Infrastructure 
L iving with Coastal Waters 
Site-Specific Adaptation Measures 
Shoreline Adaptation Measures 
Regulation and Policy 
Implementation 
Next Steps 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
IDENTIFY 
PRIORITIZE 
STRATEGIZE

b 
List of Tables 
Table E-1 Prioritized Critical Public Infrastructure iii 
Table E-2 Shoreline Adaptation Concept Information v 
Table E-3 Pump Station Adaptation Concept Information v 
Table 5-1 Flood Area Existing Conditions – Belle Isle Marsh 5-3 
Table 5-2 Probable Future Flooding – Belle Isle Marsh 5-4 
Table 5-3 Flood Area Existing Conditions – Nahant Avenue 5-5 
Table 5-4 Probable Future Flooding – Nahant Avenue 5-6 
Table 5-5 Flood Area Existing Conditions – Winthrop Beach 5-7 
Table 5-6 Probable Future Flooding– Winthrop Beach 5-8 
Table 5-7 Flood Area Existing Conditions - Lewis Lake 5-11 
Table 5-8 Probable Future Flooding – Lewis Lake 5-12 
Table 5-9 Flood Area Existing Conditions – Point Shirley 5-14 
Table 5-10 Probable Future Flooding – Point Shirley 5-15 
Table 5-11 Flood Area Existing Conditions – Fishermen’s Bend 5-17 
Table 5-12 Probable Future Flooding – Fishermen’s Bend 5-17 
Table 5-13 Flood Area Existing Conditions – Ingleside Park 5-19 
Table 5-14 Probable Future Flooding – Ingleside Park 5-19 
Table 5-15 Flood Area Existing Conditions – Girdlestone Road 5-20 
Table 5-16 Probable Future Flooding – Girdlestone Road 5-21 
Table 6-1 Critical Public Infrastructure Risk Scores and Ranking 6-5 
Table 8-1 Range of costs for site adaptations 8-3 
Table 8-2 Potential Sewer Pump Station Flood Depths and Adaptation Installations 8-4 
Table 11-1 Range of costs for Pump Station adaptations 11-1 
Table 11-2 Range of costs for shoreline / area adaptation 11-2 
Table 11-3 Potential Permits Needed for Shoreline Construction 11-4

c 
List of Figures 
Figure E-1 Locus Map i 
Figure E-2 Map of 2030 Flood Areas and Adaptation Locations iv 
Figure 3-1 Fisherman's Bend, October 2016 3-2 
Figure 3-2 Town-Identified Areas of Local Flooding 3-3 
Figure 3-3 Winthrop Areas of Probable Flooding 3-5 
Figure 3-4 Winthrop Depth of Flooding (1% Chance water level) 3-6 
Figure 3-5 Areas where Wetland Mitigation will be Limited by Existing Development 3-8 
Figure 3-6 Winthrop SLAMM Maps 3-9 
Figure 3-7 2070 SLAMM Model with Existing Development 3-10 
Figure 4-1 Town-Identified Critical Public Infrastructure Locations 4-1 
Figure 5-1 Town-Identified Areas of Local Flooding 5-1 
Figure 5-2 Timeline of Storm Structure Construction along Winthrop Beach 5-9 
Figure 6-1 Prioritized Critical Public Infrastructure in Winthrop 6-4 
Figure 9-1 Map of Adaptation Locations 9-6 
Figure 9-2 Belle Isle Marsh Coastal Flood Modeling for Projected 2030 1% Chance Storm 9-8 
Figure 9-3 Potential Flood Levels at the Belle Isle Bridge 9-9 
Figure 9-4 Morton Street Concept Plan 9-10 
Figure 9-5 Section A-A 1 (Morton Street) 9-10 
Figure 9-6 Potential Morton Street Flood Levels 9-11 
Figure 9-7 Ingleside Park Coastal Flood Modeling for Projected 2030 1% Chance Storm 9-13 
Figure 9-8 Pleasant Street Concept Plan 9-14 
Figure 9-9 Potential Pleasant Street Flood Levels 9-15 
Figure 9-10 Section A-A 1 (Pleasant Street ) 9-15 
Figure 9-11 Lewis Lake Coastal Flood Modeling for Projected 2030 1% Chance Storm 9-17 
Figure 9-12 Washington Avenue Concept Plan 9-20 
Figure 9-13 Section A-A 1 (Washington Avenue) 9-20 
Figure 9-14 Potential Washington Avenue Flood Levels 9-21 
Figure 9-15 Point Shirley Coastal Flood Modeling for Projected 2030 1% Chance Storm 9-23 
Figure 9-16 Point Shirley Concept Plan 9-24 
Figure 9-17 Section A-A 1 (Yirrell Beach) 9-25

d 
List of Appendices 
Appendix A - Glossary of Terms and Abbreviations 
Appendix B - References A-5 
Appendix C - Inundation Modeling A-9 
Appendix D - Boston Harbor Flood Risk Model (BH-FRM) Mapping A-13 
Appendix E - Probability of Exceedance Curve Data A-21 
Appendix F - Winthrop Natural Resource Evolution Summary A-31 
Appendix G - Critical Public Infrastructure Scoring Guidance A-45 
Appendix H - Infrastructure Criticality Matrix A-47 
Appendix I - Critical Infrastructure Risk Scores A-53 
Appendix J - Modeled Flood Pathways A-55 
Appendix K - Modeled Adaptation Measures A-61

i EXECUTIVE SUMMARY 
Living in a coastal community, most Winthrop 
residents are not surprised by the likelihood 
of increased coastal flooding as a result of 
climate change. They have experienced more 
intense, frequent storms in recent years and 
seen the effect that the combined impact of 
storm surge and sea level rise can have upon 
the shoreline. Residents expect that areas 
experiencing coastal flooding, and perhaps 
increased flooding, will continue to experience 
flooding in the future if preventative measures 
are not taken. That being said, most residents 
have not thought much about how increased 
coastal flooding could impact the infrastructure 
systems that support their daily lives, and 
change the natural resources that are an 
important part of the physical character of the 
town. 
Based on the Boston Harbor Flood Risk 
Model (BH-FRM), approximately 480 acres of 
Winthrop’s 1.6 square miles is within a coastal 
flooding area in present day, 500 acres in 2030, 
and 800 acres in 2070 at a 1% chance water 
level. The 1% chance water level depicts the 
flood impacts of a storm event that occurs 
every 100 years. While the flood area doesn’t 
expand dramatically in future years due to the 
geographic and topographic lay of the land 
(e.g. series of drumlins connected by low lying 
land), the depth of flooding during a storm 
event does increase dramatically looking to 
2070. 
From a regional perspective, coastal flooding 
in Winthrop has the potential for widespread 
impacts given the Town’s geographic location 
within Boston Harbor and as the only landside 
connection to the Massachusetts Water 
Resource Authority’s Deer Island Wastewater 
Treatment Plant. Winthrop is an important part 
of the Boston Harbor Flood Barrier Study, 
which is being led by UMass Boston with 
CLIMATE CHANGE 
"any significant change in the 
measures of climate lasting for an 
extended period of time, including 
major changes in temperature, 
precipitation, or wind patterns." 
- US EPA (2014) 
Winthrop 
Boston 
Hull 
Quincy 
Weymouth 
Hingham 
Revere 
Nahant 
BOSTON 
HARBOR 
Figure E-1 Locus Map 
Winthrop's location within Boston Harbor 
support from the Barr Foundation. 
The criticality of Winthrop to the region 
broadens the resilience dialogue and heightens 
the need for proactive adaptation planning. 
RESILIENT WINTHROP: Executive Summary

ii EXECUTIVE SUMMARY 
Assessment Process and 
Findings 
This Climate Change Vulnerability Assessment 
followed a three step identify-prioritize- 
strategize process focused on the vulnerability 
of public infrastructure and natural resources 
to coastal flooding. 
Identify: What areas of Winthrop are 
at risk of coastal flooding? What public 
infrastructure is located in these areas? 
Eight (8) primary flood areas were 
identified within Winthrop. Withing these 
areas, there were sixteen (16) critical 
public infrastructure assets/facilities 
susceptible to coastal flooding. 
Prioritize: How critical is this 
infrastructure and what is the likelihood 
that it will flood? 
Assets/facilities were ranked by criticality 
independent of flood risk. Highest ranked 
assets included Shirley Street, Argyle 
Street Substation, emergency evacuation 
routes, and the pump station. Factoring in 
the probability of flooding led to certain 
assets/facilities becoming a higher or lower 
priority. Pump stations and key emergency 
evacuation routes received the highest risk 
score and thus priority. 
The following table shows the prioritized 
critical public infrastructure in Winthrop. Town 
officials and the consulting team all took part 
in the prioritization process. 
Contained within the Winthrop mapped coastal 
flooding areas are critical public infrastructure 
assets/facilities that support daily life in 
Winthrop - sewer pump stations, evacuation 
routes, a substation, pressure reducing valve 
stations, Winthrop High School, Beach Fire 
Station, and Town Landing, for example. 
Each of these assets/facilities are critical for: 
The last criticality criteria accounts for 
the fact that loss or damage from coastal 
flooding could be limited to one property or a 
neighborhood, it could also have widespread 
impacts to the town or region. 
Public Safety & Emergency 
Services: How important is the 
asset to community evacuation and 
disaster response operations? 
Social & Economic Activities: 
How important is the asset to 
providing people with access or 
service to their homes and jobs? 
Public Health & Environment: 
How important is the asset to 
controlling human exposure to 
pollutants and secondary impacts 
to the natural environment? 
Area of Service Loss: Who is 
impacted by the loss of or damage 
to the core functions of the asset?

iii EXECUTIVE SUMMARY 
Strategize: How can Winthrop adapt 
to coastal flooding to help protect the 
critical public infrastructure in town? 
Based on priority ranking, one asset type 
(pump stations) and four flood areas 
(Belle Isle Marsh, Ingleside Park, Lewis 
Lake, and Point Shirley) were selected 
for concept designs. Creative adaptation 
concepts of various scales (site-specific vs. 
shoreline) were considered, each of which 
addressing the technical aspects of coastal 
flooding and advancing community and 
environmental goals. 
PRIORITY 
RANK CRITICAL PUBLIC INFRASTRUCTURE FLOOD AREA SECTOR 
1 Pico Sewer Pump Station Fishermen's Bend Water and Wastewater 
2 Pleasant Court Sewer Pump Station Belle Isle Marsh Water and Wastewater 
3 Washington Street (town evacuation route) Lewis Lake Transportation - Roadway 
4 Main Street (town evacuation route) Belle Isle Marsh Transportation - Roadway 
5 Pleasant Street (town evacuation route) Ingleside Park Transportation - Roadway 
6 Beach Fire Station Lewis Lake Buildings 
7 Winthrop High School Lewis Lake Buildings 
8 Pressure Reducing Valve Station (Bayview Avenue) Point Shirley Water 
9 Pressure Reducing Valve Station (Underhill Street) Winthrop Beach Water 
10 Shirley Street (town evacuation/MWRA truck route) Point Shirley Transportation 
11 Public Landing Point Shirley Transportation - Maritime 
12 Pressure Reducing Valve Station (Revere Street) Belle Isle Marsh Water 
13 Revere Street Sewer Pump Station Belle Isle Marsh Water and Wastewater 
14 Belle Isle Bridge Belle Isle Marsh Transportation - Roadway 
15 Power Substation (Argyle Street) Belle Isle Marsh Energy 
16 Loring Road Boat Ramp Ingleside Park Transportation - Maritime 
Complementary to the assessment’s focus on 
publicly-owned infrastructure systems was 
consideration of the impact of sea level rise 
and storm surge to natural resources. The 
Commonwealth’s Sea Level Affecting Salt 
Marshes Model (SLAMM) shows the likely 
progression of wetland migration across 
Winthrop over the next several decades. 
A large portion of the projected wetland 
transitions and expansions are predicted to 
occur in the existing open areas of Winthrop, 
including, but not limited to, wetlands adjacent 
to the Winthrop Cemetery and Coughlin Park. 
These areas will likely experience significant 
changes in land cover and wetland type and 
may offer opportunities for natural resource 
management and/or expansion due to the 
changing climate. 
Table E-1 Prioritized Critical Public Infrastructure

iv EXECUTIVE SUMMARY 
Lewis
Lake 
Snake
Island 
Coughlin
Park
Deer Island 
Boston Logan
International Airport 
Deer Island
Wastewater
Treatment Plant 
N 
SHORT BEACH
CREEK
BELLE ISLE
MARSH
BOSTON
HARBOR
BOSTON
HARBOR
BOSTON
HARBOR
BELLE ISLE
INLET
BROAD SOUND
BROAD SOUND 
The Five Sisters 
Winthrop
Head
Winthrop
Beach
Donovan’s
Beach 
Crystal
Cove 
Town
Landing 
Pico Playground
& Beach 
Town
Hall 
Winthrop
High School 
Small Park
Small Beach
Fort Banks
Playground
Yirrell
Beach
Little
League
Field Miller
Field
Winthrop
Golf Club
Veterans
Field 
Central Business
District 
The Basin 
Winthrop
Cemetery 
Washington Ave
Winthrop St
Winthrop St
Main St
Pleasant St
Shirley St
Shirley St
Veterans Road
Winthrop Shore Dr
Revere St
Morton Street 
Figure E-2 Map of 2030 Flood Areas and Adaptation Locations 
REVERE ST PUMP 
STATION 
PLEASANT COURT 
PUMP STATION 
PICO AVE PUMP 
STATION 
NAHANT AVENUE 
FLOOD AREA 
(7.5 AC) 
LEWIS LAKE 
FLOOD AREA 
(153 AC) 
BELLE ISLE MARSH 
FLOOD AREA 
(106 AC) 
INGLESIDE PARK 
FLOOD AREA 
(38 AC) 
WINTHROP BEACH 
FLOOD AREA 
(88 AC) 
POINT SHIRLEY 
FLOOD AREA 
(88 AC) 
Shoreline Adaptation 
Site Specific Adaptation 
FISHERMEN'S BEND 
FLOOD AREA 
(35 AC)

v 
Adaptation Concepts 
Shoreline Adaptations 
Shoreline strategies for four focus areas were advanced to concept designs. The concept designs were modeled for effectiveness using the BH-FRM for the 1% chance flood depth in 2030 (the depth of flooding relative to sea 
level and storm surge during a 100 year storm event). The height of each adaptation was modeled at this elevation, plus one foot of freeboard (e.g. a 4-foot projected water surface elevation would be modeled for a 5-foot-tall 
barrier). Each adaptation should allow for additional linear or vertical modifications to account for changes in future conditions. The following tables contain general information and cost estimates for each adaptation concept. 
* Estimates include approximate cost of materials 
and labor for installation. Estimates do not include 
design, permitting, right-of-way acquisition, 
construction mobilization and demobilization, 
operations, or maintenance. 
Key to Estimated Range of Costs: 
$ = <$100,000 ; $$ = $100,000 
to $500,000 ; $$$ = $500,000 to 
$3,000,000 ; $$$$ = $3,000,000 
PUMP STATION ADAPTATION TYPE CONSTRUCTION COST ESTIMATE* 
Stop Logs $4,000 - $6,000 each 
Watertight Exhaust Ducts $10,000 - $15,000 each 
Watertight Floor Hatches $10,000 - $15,000 each 
Repoint Building Façade 5-feet above grade $20 - $30 per square foot 
Waterproof Building Façade 5-feet above grade $5 - $10 per square foot 
Raise Outdoor Equipment Pads $500 – $1,000 each 
Raise Electrical Equipment Supports $10 - $20 each 
Work Platforms for Raised Electrical Equipment $50 - $100 each 
5-ft Concrete Perimeter Wall $300 - $500 per linear foot 
FLOOD 
AREA 
APPROX. 
2030 
FLOOD 
AREA 
(ACRES) 
CRITICAL PUBLIC 
INFRASTRUCTURE 
1% CHANCE 
FLOOD DEPTH 
(FEET) RECOMMENDED ADAPTATION 
CONCEPT 
POTENTIAL 
HEIGHT OF 
INSTALLATION 
(FEET) 
POTENTIAL 
LENGTH OF 
INSTALLATION 
(FEET) 
MODELED EFFECTIVENESS FOR FLOOD PROTECTION 
UNDER 1% CHANCE FLOOD DEPTH (2030) 
2030 COST OF 
CONSTRUCTION* 
2070 ADDITIONAL 
COST* 
2030 2070 
Belle Isle 
Marsh 106 
Main Street (Evacuation 
Route & Deer Island 
Trucking Route) 
2'-25'' 6' Planted berm / elevated sidewalk with 
knee wall along Morton Street right-of-way. 1'-3" 625 Relatively ineffective solely along Morton Street. Needs to extend further 
west & south along the inlet. $$$ $$$-Engineered 
flood barrier 
Ingleside 
Park 38 Pleasant Street (Evacuation 
Route) 8'' 3'-5'' Hybrid seawall, with seating & planting 
adjacent to Donovan’s Beach. 1'-9" 325 Effective as a coastal flood adaptation. $$$ $$-Engineered 
flood barrier 
Lewis Lake 153 
Washington Avenue 
(Evacuation Route, 
Winthrop High School) 
1'-5'' 4'-25" Flood barrier at Washington Avenue. 2'-6" 900 Effective as a coastal flood adaptation, if culvert & tide gate system at 
Crystal Cove work as intended. $$$ $$ 
Point 
Shirley 88 
Shirley Street/Tafts Avenue 
(Evacuation & Deer Island 
Trucking Route) 
12'' 4' 
Beach nourishment / dune creation at Yirrell 
Beach (pending design study). Pending design 
study 3,850 Effective in reducing wave overtopping & flood depth levels if properly 
engineered. 
$ $$$$$ 
Dune creation at Yirrell Beach (pending 
design study). $$$$ to $$$$$ $$$$$ 
Site Specific Adaptations 
Three major sewer pump stations in town are identified within BH- 
FRM flood areas. These stations collect and distribute hundreds of 
thousands of gallons of sewage each day. The stations are at specific 
low points in the community to collect neighborhood waste and 
pump it out to the larger sewer mains. Pump station retrofits such as 
perimeter walls and dry floodproofing techniques and other information 
are identified in the following table. These adaptation measures may 
also be applied to other asset types, private residences and commercial 
buildings. 
Table E-2 Shoreline Adaptation Concept Information 
Table E-3 Pump Station Adaptation Concept Information 
EXECUTIVE SUMMARY

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vii EXECUTIVE SUMMARY 
Following completion of this assessment, 
the next step for the Town is to advance 
the concept designs and assessment 
recommendations towards implementation and 
expand the resilience discussion to include 
consideration of other climate-related hazards 
and community assets. Doing so will require 
a commitment from the Town, its residents 
and business owners, and agency partners to 
advance community resilience at all scales in 
the short and long term. 
In Fall 2017, the Town will begin a community 
resilience building workshop process as part of 
the Commonwealth’s Municipal Vulnerability 
Preparedness (MVP) Program . This Program 
expands the focus from just coastal flooding to 
include consideration of other climate-related 
hazards such as increased precipitation and 
heat, for example. Results of the workshop 
and planning efforts will be used to inform 
existing local plans, grant applications, 
budgets, and policies. 
This study was completed with a cross section 
of input from residents at two public meetings 
and the help of the Project Management Team 
which included representation from the Town 
Manager’s Office, Department of Public 
Works, Fire Department, Police Department, 
Conservation Commission, Massachusetts 
Office of Coastal Zone Management and the 
consultant team from Stantec and Woods Hole 
Group.

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1-1 VULNERABILITY ASSESSMENT PURPOSE 
Many small coastal communities in 
Massachusetts have experienced the waves, 
high winds, and severe flooding that are 
delivered by Nor’easters and hurricanes. 
These storms can damage homes, cause 
power outages, and impact local and regional 
infrastructure and operations. Sea levels 
are anticipated to rise more than six inches 
over the next 15 years, and more than three 
feet over the next 50 years. Climate change 
is expected to cause higher high tides and 
longer, more intense, and more frequent 
storms. Therefore, it is important for coastal 
communities like Winthrop to prepare for an 
unpredictable future environment. 
As the Commonwealth advances an integrated 
climate change strategy (Executive Order 
569), Massachusetts communities are working 
to implement policies and adaption measures 
at the regional and local level to enhance 
resiliency and climate preparedness. At the 
regional level, the Metro Mayors Coalition 
set climate preparedness as its programmatic 
priority, and established the Metro Boston 
Climate Preparedness Taskforce. The 
Taskforce is working to shape and drive 
forward increased collaborations that advance 
regional resiliency. 
STUDY GOAL: 
To identify and prioritize critical 
public infrastructure vulnerable 
to coastal flooding and explore 
adaptation measures to improve 
infrastructure and natural resource 
resilience over a range of future 
conditions. 
1 VULNERABILITY ASSESSMENT 
PURPOSE 
View of the Winthrop Water Tower as seen 
from Pico Beach

1-2 VULNERABILITY ASSESSMENT PURPOSE 
Through participation on the Taskforce and 
a review of municipal priorities, the Town of 
Winthrop has proactively begun to design and 
construct improvements to reduce the impacts 
of coastal flooding at critical infrastructure 
locations. Efforts like the Winthrop Hazard 
Mitigation Plan, Winthrop Harbor Plan, and 
Coughlin Park Green Infrastructure Study have 
exhibited the Town’s commitment to assessing 
the vulnerability levels and existing conditions 
of both the built and natural environment. 
Other state and federally funded efforts to 
address coastal flooding in Winthrop include 
improvements along Winthrop Shore Drive, 
Winthrop Beach, Tafts Avenue, and Lewis 
Lake. 
Each of these infrastructure improvement 
projects addresses flooding issues in different 
areas of Winthrop. However, the Town 
recognizes the need to take a step back and 
evaluate critical infrastructure at a Town- 
COMMUNITY 
RESILIENCE 
"the capability to anticipate 
risk, limit impact, and bounce 
back rapidly through survival, 
adaptability, evolution, and growth 
in the face of ... change." 
- Definitions of Community Resilience: An 
Analysis (A CARRI Report) 
wide level. This vulnerability assessment will 
assist the Town with the prioritization and 
strategic implementation of projects to help 
infrastructure assets and areas most at risk 
from coastal flooding become more resilient. 
This information will also inform individual 
home-owners about what they might expect on 
their own properties, regarding future coastal 
flooding. 
Row boat on flooded Shirley Street, November 1932, 
Courtesy of the Boston Public Library, Leslie Jones Collection.

2-1 VULNERABILITY ASSESSMENT PROCESS 
2 VULNERABILITY ASSESSMENT 
PROCESS 
Settled in 1630, Winthrop is one of the oldest 
communities in the United States. At 1.6 
square miles and an estimated population of 
17,500, Winthrop is also one of the smallest 
and most densely populated municipalities 
in Massachusetts. With 8.3 miles of tidal 
shoreline and a small geographic footprint, 
Winthrop is particularly vulnerable to coastal 
flooding from sea level rise and climate 
change. 
The increasing chance of coastal flooding 
threatens Winthrop’s shoreline, including 
public facilities, infrastructure, recreational 
areas, and coastal ecosystems. Today, 
VULNERABILITY: 
"Structures, systems, populations, 
or other community assets as 
defined by the community, that 
are susceptible to damage and 
loss from hazard events." 
- FEMA Local Mitigation Plan Review Guide 
(2011) 
Source: Winthrop town website 
approximately 45% of the 1.6 sq mi town is 
within a flood zone. That's nearly 480 acres. 
By 2030, it could increase to 50% (500 acres), 
and 60% (800 acres) by 2070.

2-2 VULNERABILITY ASSESSMENT PROCESS 
PRIORITIZE 
How critical is this infrastructure 
and what is the likelihood that it 
will flood? 
STRATEGIZE 
How can Winthrop adapt to 
coastal flooding to help protect 
the critical public infrastructure in 
town? 
IDENTIFY 
What areas of Winthrop are at risk 
of coastal flooding? What public 
infrastructure is located in these 
areas? 
The assessment begins by explaining the 
development history of Winthrop and the 
areas of the Town most likely to experience 
coastal flooding based on sea level rise 
projections and a wide range of potential 
storm events. This information allows us 
to locate existing public infrastructure and 
natural resources within seven vulnerable 
areas of the Town. (Chapters 3 , 4 & 5 ) 
The next step includes evaluating identified 
public infrastructure assets based on how 
critical they are to the community-at-large, 
and how likely they are to flood in present 
day, 2030, and 2070. The result is a total 
risk score that can be used as the basis for 
prioritizing investments. (Chapter 6 ) 
The last part of the assessment 
recommends site-specific, shoreline, 
and policy or regulatory measures 
to improve the resilience of critical 
public infrastructure. It also lays the 
foundation for follow on efforts and future 
implementation phases. (Chapters 7 - 12 ) 
Considering this, the goal of this climate 
change vulnerability assessment is to evaluate 
potential impacts of coastal flooding in the 
Town of Winthrop, based on what we know 
about extreme weather and sea level rise, and 
to identify measures to protect critical public 
infrastructure. 
A 3-step process was followed for this 
assessment:

2-3 VULNERABILITY ASSESSMENT PROCESS 
Throughout the assessment process, critical 
infrastructure, potential areas of flooding, 
and neighborhoods were targeted through the 
cooperative engagement of a consultant team, 
residents, and the input of Town staff. 
The Town established a Project Management 
Team (PMT) to facilitate and manage project 
implementation. The Team met on multiple 
occasions to share local knowledge, review 
datasets, and discuss preliminary concepts. The 
PMT includes: 
• Joe Domelowicz Jr., Assistant to 
the Town Manager for Grants and 
Economic Development 
• Steve Calla, Department of Public 
Works Director 
• Terrence Delehanty, Police Chief 
• Paul Flanagan, Fire Chief 
• Kara Campbell, Conservation Agent 
• Lisa Engler & Patricia Bowie, Coastal 
Zone Management (CZM) 
• Staff from the consultant team at 
Stantec and Woods Hole Group 
Two public meetings were held throughout the 
project to gather local knowledge and opinion: 
The first public meeting was held on April 5, 
2017 at EB Newton to: 
• explain the purpose and scope of the 
project 
• present the Boston Harbor Flood Risk 
Maps (BH-FRM) modeling by Woods 
Hole Group 
• provide an opportunity to ask 
questions. 
An open house and public meeting was held on 
May 23, 2017 at Winthrop Town Hall to: 
• present the BH-FRM modeling for 
future years 2030 and 2050 (Chapter 3) 
• explain how critical infrastructure was 
identified and selected (Chapter 6) 
• present potential adaptation measures 
for sites and shorelines throughout 
town (Chapter 7) 
• provide an opportunity to comment and 
ask questions. 
A meeting was also held with the Department 
of Conservation and Recreation (DCR) on 
June 12, 2017. A subsequent meeting will 
be scheduled with the Massachusetts Water 
Resources Authority (MWRA) to discuss the 
findings of this assessment. 
April 5, 2017 public meeting at EB Newton,

2-4 
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3-1 IDENTIFY: Future Areas of Coastal Flooding 
1894 drawing of Winthrop, showing 
Washington Street Bridge over Fisher's Creek 
(AF Poole) 
This section focuses on understanding where 
Winthrop has and is experiencing flooding, 
where there are likely future flooding 
locations, and what has been done to address 
the flood risk. Once the challenge locations are 
known, a conversation can be had regarding 
potential adaptation measures and means of 
project funding. 
Coastal flooding occurs when the waves, storm 
surge, and tides overtop the shoreline and 
low-lying areas become submerged. While 
there are additional factors that contribute to 
flooding within our built environments (such 
as intense precipitation events that can cause a 
rising water table and increase in stormwater 
runoff from roofs, roadways, and parking 
areas), coastal based flooding is the focus 
of this vulnerability assessment. Additional 
localized flooding should also be assessed as 
part of future studies. 
Coastal Development in 
Winthrop 
Winthrop was settled by Europeans in 1635 
(MHC, 1981). Historic mapping shows four 
farming plots during this period, and a small 
fishing village at Point Shirley by the mid-18 th 
century. These maps also illustrate the marsh 
land and open water that has filled over the 
years due to natural events and human activity. 
The most notable changes include Fisher’s 
Creek and Shirley Gut. 
3 IDENTIFY: Future Areas of 
Coastal Flooding 
Figure 2. Historic Map of Boston Harbor, 1775 
Illustration of Point Shirley, Deer Island, and 
Shirley Gut, c. 1775. ("Boston: Its Environs and 
Harbour," Sir Thomas Hyde)

3-2 IDENTIFY: Future Areas of Coastal Flooding 
Lewis Lake was previously an extensive marsh 
surrounding Fisher’s Creek. It was open to 
Boston Harbor until the mid-19th century, but 
was bridged in the 1880s and subsequently 
filled, with a tide gate installed in the early 
20th century (MHC, 1993). Shirley’s Gut once 
separated Point Shirley from Deer Island. By 
the 20th century, sand drifted into the narrow 
waterway, and the Hurricane of 1938 finally 
filled it, connecting Winthrop to Deer Island 
(Culhane et. al.). Locations such as these 
are common around town, where low lying, 
previously wet land is now developed. 
The existing high tide elevation is currently 
between 9 and 10 feet. Sea level rise can be 
gaged during King Tides ( Figure 3-1 ). This 
extreme tide event suggests what the average 
high tide may look like within the next half 
century (DeCosta-Klipa, 2016). Of note, 
the King Tide on October 17-19, 2016 was 
between one and two feet higher than a normal 
high tide. 
The areas of filled tidelands and the rising 
sea level give some indication of where the 
water wants to go during storms and/or high 
tide events. This idea is emphasized in the 
historic and present account of the flooding in 
Winthrop, as well as the future coastal flood 
modeling, presented in this chapter. 
KING TIDE 
The King Tide is the highest predicted high 
tide of the year at a coastal location. It is 
above the highest water level reached at 
high tide on an average day 
- US EPA (https://www.epa.gov/cre/king- 
tides-and-climate-change) 
Figure 3-1 Fisherman's Bend, October 2016, at typical high tide (left) and King Tide (right) 
(mycoast.org King Tide Report by Joanne Anderson)

3-3 IDENTIFY: Future Areas of Coastal Flooding 
Historic and Current Flooding 
Locations 
Several recorded and anecdotal storm events, 
specific to coastal flooding, were noted in 
the 2014 Winthrop Hazard Mitigation Plan 
(HMP), including: 
• 16 coastal flood events between 2006 
and 2014, resulting in $3.11 million in 
property damage. 
• 40 heavy snowfall events between 
1996 and 2014, including $9.6 million 
in property damage. 
• Ten severe winter storms recorded 
between 1978 and 2013 – seven of 
which occurred after the year 2000. 
The coastal flood of 1978 (blizzard) remains 
the record high flooding event in Winthrop 
to date. After the Blizzard of 1978, high 
water marks inventoried by the United States 
Geological Survey, U.S. Army Corps of 
Engineers, and Massachusetts Department of 
Public Works were recorded between 9.5 and 
12 feet above Mean Sea Level. (HMP, 2014) 
The Federal Emergency Management Agency 
(FEMA) uses historical climate information 
to estimate potential damages from natural 
hazards. Flood zones are modeled to define 
areas at risk of flooding. The areas are 
illustrated on Flood Insurance Rate Maps 
(FIRMs), which identify properties required to 
obtain flood insurance. 
The FIRMs issued in 2016 for Winthrop show 
approximately 45% of town within the 1% 
annual chance flood (also known as the 100- 
year storm). 
Anecdotal information regarding local 
flooding, gathered from the town during 
the 2014 Winthrop Hazard Mitigation Plan, 
supports the FEMA data. In addition to 
identifying various seawalls and headwalls 
(Woodside Ave, Somerset Ave, Sargent St, 
Cottage Park Rd), areas of local flooding 
included: 
Yirrell Beach 
Shirley Street Neighborhood 
Lewis Lake 
Ingleside Park 
Lower Nahant Avenue 
Coughlin Park 
Bayou Street Neighborhood 
A more in-depth review of these areas 
is included as part of Chapter 5 of this 
vulnerability assessment. 
Figure 3-2 Town-Identified Areas of Local 
Flooding 
REVERE 
DEER 
ISLAND 
A 
B 
C 
D 
E 
F 
G 
A 
B 
C 
D 
E 
F 
G

3-4 IDENTIFY: Future Areas of Coastal Flooding 
Boston Harbor Flood Risk 
Model (BH-FRM) 
A scientifically accurate, dynamic, robust, 
and probability-based analysis of potential 
flooding in Winthrop is key to effectively 
evaluate the risks of future sea level rise 
and storm surge. This allows the Town to 
identify and prioritize areas and assets within 
probable areas of flooding. Then potential 
adaptation options can be studied in order to 
build overall resilience for the community. 
Using established techniques and previously 
generated model data from work with the 
Massachusetts Department of Transportation, 
probabilistic flood information forms the basis 
for the vulnerability assessment in the Town of 
Winthrop. 
Sea level rise and storm surge can be modeled 
in a number of different ways. This assessment 
utilizes the Boston Harbor Flood Risk Model 
(BH-FRM) to provide results for the Town 
of Winthrop. The model, called the Boston 
Harbor Flood Risk Model (BH-FRM), is 
used to provide the results for the Town of 
Winthrop. 
Concern about potential impacts to the 
City of Boston from future storms drove 
the creation of the BH-FRM – a model 
with the best representation of the physical 
processes, as well as accurate and higher 
resolution predictions of inundation due to 
the combination of sea level rise and storm 
surge. The hydrodynamic modeling utilized for 
the BH-FRM was geared towards a physics- 
based approach to determine the water level 
increases and flooding, and provided results 
to identify specific locations that may require 
adaptation alternatives. 
For this project, Woods Hole Group (WHG) 
has produced two types of BH-FRM maps to 
illustrate potential impacts to areas of coastal 
flooding: 
1. The probability, or likelihood, of 
coastal flooding today and in future 
years 2030 and 2070 ( Figure 3-3 ). A 
range of percent chance spans from 
100% (annual storm condition) to 0.1% 
(a one in 1,000 chance storm – a less 
frequent, more intense occurrence). 
2. Depth of flooding, relative to sea 
level ( Figure 3-4 ). These maps show 
different depths for present day, 2030, 
and 2070, associated with both the 1% 
(1 in 100) and 0.1% chance floods. 
For more in-depth information about the BH- 
FRM, see Appendix D . 
HYDRODYNAMIC 
MODEL 
MODELED STORM EVENTS 
Including hurricanes and nor'easters, as well as 
climatology projections. 
SEA LEVEL RISE PROJECTIONS 
Consistent with both the US National Climate 
Assessment and projections specific to 
Massachusetts. 
DYNAMIC COASTAL PROCESSES 
Driven by wave effects, wind, tides, and storm 
surge. 
Mapping Coastal Flooding: 
BH-FRM results are based on a 
hydrodynamic model developed 
for the Massachusetts Department of 
Transportation (Bosma et al. 2016). 
Note: This data does not take into account 
inland freshwater flooding or stormwater.

3-5 IDENTIFY: Future Areas of Coastal Flooding 
2013 2030 2070 
Figure 3-3 Winthrop Areas of Probable Flooding 
Present Day 
BROAD SOUND 
CRYSTAL 
COVE 
BOSTON 
HARBOR 
BELLE ISLE 
MARSH 
BROAD SOUND 
CRYSTAL 
COVE 
BOSTON 
HARBOR 
BELLE ISLE 
MARSH 
BROAD SOUND 
CRYSTAL 
COVE 
BOSTON 
HARBOR 
BELLE ISLE 
MARSH

3-6 IDENTIFY: Future Areas of Coastal Flooding 
Present Day 2030 2070 
Figure 3-4 Winthrop Depth of Flooding (1% Chance water level) 
BROAD SOUND 
CRYSTAL 
COVE 
BOSTON 
HARBOR 
BELLE ISLE 
MARSH 
BROAD SOUND 
CRYSTAL 
COVE 
BOSTON 
HARBOR 
BELLE ISLE 
MARSH 
BROAD SOUND 
CRYSTAL 
COVE 
BOSTON 
HARBOR 
BELLE ISLE 
MARSH

3-7 IDENTIFY: Future Areas of Coastal Flooding 
Natural Resource Modeling 
Climate change, with increased storm intensity, 
changes in precipitation patterns, and global 
sea-level rise will exacerbate already difficult 
coastal management issues related to both 
infrastructure and natural resources (Bosma 
et al., 2015). Recent studies have identified 
sea-level rise as one of the most certain and 
potentially destructive impacts of climate 
change (Meehl et al., 2007). Coastal wetlands 
are among the most susceptible ecosystems to 
climate change, especially accelerated sea- 
level rise. (Nicholls et al. 2009) points out that 
coastal wetlands, including salt marshes and 
intertidal areas, could experience substantial 
area losses due to sea-level rise. Because 
coastal wetlands are extremely productive 
ecosystems, and provide a variety of 
ecosystem services, such as flood protection, 
waste assimilation, nursery areas for fisheries, 
and conservation and recreation benefits, such 
loss would have a high human cost. 
Recognizing the threats posed by climate 
change and sea-level rise, the Massachusetts 
Office of Coastal Zone Management (CZM) 
desired to assess and analyze the effects of 
sea-level rise on coastal wetlands for the 
Commonwealth of Massachusetts (Woods 
Hole Group, 2016). The project’s intent was to 
simulate the effects of sea-level rise using an 
ecological model and implement the model at 
its highest level of complexity. 
The model selected to evaluate the impact of 
sea level rise on coastal resources was the Sea 
Level Affecting Marshes Model (SLAMM), 
originally developed with EPA funding in 
the 1980s. The SLAMM model attempts to 
capture the major coastal processes, at least 
at a rudimentary level, involved in wetland 
conversions and shoreline modifications 
expected to occur over a long term. 
The results of the marsh migration modeling 
are intended to be used for future coastal 
planning in a number of ways. For instance, 
model results from this project can be used 
to identify areas with barriers to landward 
migration of salt marshes. These results can 
therefore serve as a guide for development 
and implementation of adaptation strategies 
for coastal managers and policymakers to 
proactively address potential impacts from 
long-term sea-level rise. The results produced 
for the Town of Winthrop have been extracted 
from the larger CZM Commonwealth of 
Massachusetts project for this assessment. 
More in-depth information on SLAMM is 
provided in Appendix F . 
The SLAMM results ( Figure 3-6 ) project some 
minor wetland expansion and loss of upland 
area in 2030. This expansion will occur at 
the fringes of existing wetlands in areas that 
are already designated as open space, and 
should not interfere with existing development 
much differently than in current conditions. 
By 2070, sea-level rise is projected to induce 
large scale shifts across Winthrop, including 
transitions from irregularly flooded marsh 
to regularly flooded marsh, expansion of 
wetlands into transitional marsh scrub-shrub 
habitat, expansion of beach and tidal flat areas, 
conversion of inland open water to estuarine 
open water, and expansion of open ocean water 
areas ( Figure 3-6 , right panel).

3-8 IDENTIFY: Future Areas of Coastal Flooding 
Figure 3-5 Areas where Wetland Mitigation will 
be Limited by Existing Development 
REVERE 
DEER 
ISLAND 
a 
b 
c 
d 
e 
f 
g 
h 
Some areas of potential wetlands migration 
will be limited by (and will interfere with) 
existing development ( Figure 3-5 ). These areas 
include: 
Commercial/industrial areas in the vicinity 
of Argyle Street 
Residential areas south of Banks Street and 
Morton Street 
Residential/commercial areas adjacent to 
the Belle Isle Bridge 
Residential areas around Pico Avenue 
Residential/industrial areas around 
Seaview Avenue 
Residential/commercial/municipal areas 
surrounding Lewis Lake Park and the 
Winthrop Golf Course 
Residential/commercial areas along Shirley 
Street (from Sturgis Street to Crystal Cove 
Avenue 
Residential areas southeast of Coughlin 
Park 
Due to the high density of development and 
impervious surface in these areas of Winthrop 
it is unlikely that they will be allowed to 
transition to wetland. These developed 
areas will likely experience higher water 
tables, increased salt water intrusion, day 
to day nuisance flooding (due to a higher 
daily tides), and higher frequency of storm 
flooding. Therefore, these areas will likely 
need additional protection in the future or 
retreat options under normal tidal conditions 
(accounting for sea-level rise). 
a 
b 
c 
d 
e 
f 
g 
h

3-9 IDENTIFY: Future Areas of Coastal Flooding 
Figure 3-6 Winthrop SLAMM Maps 
2030 2070 
These results are part of the Statewide Modeling the Effects of Sea Level Rise on Coastal Wetlands for Massachusetts Coastal Zone Management. (Woods Hole Group, 2016). 
Broad Sound 
Crystal Cove 
Boston 
Harbor 
Belle Isle 
Marsh 
Broad Sound 
Crystal Cove 
Boston 
Harbor 
Belle Isle 
Marsh 
Broad Sound 
Crystal Cove 
Boston 
Harbor 
Belle Isle 
Marsh 
Present Day

3-10 IDENTIFY: Future Areas of Coastal Flooding 
A large portion of the projected wetlands 
transitions and expansions are predicted to 
occur in the existing open areas of Winthrop, 
including: 
• Wetlands adjacent to the Winthrop 
Cemetery 
• Lewis Lake Park and the Winthrop 
Golf Course 
• Wetlands adjacent to Pico Beach 
• Coughlin Park 
These areas will likely experience significant 
changes in land cover and wetland type and 
may offer opportunities for natural resource 
management and/or expansion due to the 
changing climate. More detailed information 
on the changes to these four areas and 
recommended adaptations are discussed in 
Chapter 9 . 
Figure 3-7 2070 SLAMM Model with Existing 
Development 
WINTHROP 
CEMETERY 
LEWIS LAKE PARK 
& WINTHROP GOLF 
COURSE 
PICO 
BEACH 
COUGHLIN 
PARK

4-1 IDENTIFY: Critical Public Infrastructure 
Pressure Reducing Valve Station (Bayview Ave) 
Pressure Reducing Valve Station (Revere St) 
Pressure Reducing Valve Station (Underhill St) 
Public Landing 
Revere St. Sewer Pump Station 
Shirley Street (evacuation route) 
Washington Street (evacuation route) 
Winthrop High School 
L 
N 
M 
O 
P 
The combination of future sea level rise and 
storm events has the potential to damage 
important public infrastructure, such as 
evacuation routes and sewer pumping stations, 
within identified coastal flood areas throughout 
Winthrop. Due to climate change, these 
locations are in danger of becoming subject to 
conditions for which they were not designed. 
Without proper planning, damage could 
become more frequent, take longer and cost 
more to repair, and entail more socioeconomic 
disruption (EEA, 2011). 
The 2012 Hazard Mitigation Plan identified 
97 critical infrastructure locations susceptible 
to a variety of hazard events (flooding, fire, 
earthquake, etc.). These included facilities 
important for disaster response and evacuation 
and those where additional assistance might be 
needed during an emergency (HMP, 2014). 
For this vulnerability assessment, the 2012 list 
has been narrowed and edited by the Project 
Management Team (PMT) to include 16 
critical public infrastructure locations within 
areas susceptible to coastal flooding: 
4 IDENTIFY: Critical Public Infrastructure 
A 
B 
C 
D 
E 
F 
G 
Figure 4-1 Town-Identified 
Critical Public Infrastructure 
Locations 
REVERE 
DEER 
ISLAND 
H 
I 
J 
K 
A 
B 
C 
D 
E 
F 
G 
H 
I 
J 
K 
L 
N 
M 
O 
P 
Beach Fire Station 
Belle Isle Bridge 
Loring Rd. Boat Ramp 
Main Street (evacuation route) 
Pico Sewer Pump Station 
Pleasant Court Sewer Pump Station 
Pleasant Street (evacuation route) 
Power Substation (Argyle Street)

4-2 IDENTIFY: Critical Public Infrastructure 
Shoreline Structures 
Shoreline structures in Winthrop include stone 
revetment, concrete seawalls, bulkheads, 
breakwaters, and groins. The Massachusetts 
Office of Coastal Zone Management (CZM) 
provides inventory and assessment data for 
coastal infrastructure via the Massachusetts 
Ocean Resource Information System (MORIS) 
data. Publicly-owned structures, identified by 
the 2009 MORIS data, includes six structures 
owned by the Massachusetts Department 
of Conservation and Recreation (DCR) and 
27 town-owned structures in various levels 
of condition. Half of the identified public 
shoreline structures were assessed as needing 
moderate to significant levels of rehabilitation. 
How are shoreline structures 
vulnerable to coastal 
flooding? 
Shoreline structures have long been 
used as the first line of defense against 
the crashing waves of the sea. As 
sea levels rise and storms become 
stronger and more frequent, these 
structures become more susceptible 
to damage. Erosion of the soils on the 
sea side of the structures may expose 
wall foundations and cause walls to 
fail. 
Stone revetment and concrete seawall 
along Winthrop Parkway and Upland Road 
PUBLIC 
INFRASTRUCTURE 
includes Town-owned assets as 
well as state infrastructure and 
private utility assets that provide 
critical public services. 
For this assessment, critical public 
infrastructure includes transportation 
corridors, water, wastewater, and stormwater 
systems, buildings, energy and transmission 
systems, natural resources (dunes, beaches, 
salt marsh, etc.), open space, and recreational 
facilities. The following sections of this 
chapter describe why this infrastructure is 
important to the Town and region, and what 
elements are susceptible to coastal flood 
damage.

4-3 IDENTIFY: Critical Public Infrastructure 
How are buildings vulnerable 
to coastal flooding? 
Some of these buildings are within BH- 
FRM flood areas. Flooded buildings 
are particularly susceptible to water 
damage or collapse. In addition, 
sea level rise will result in higher 
groundwater elevations, which could 
compromise building foundations 
that are not supported on piles. 
Buildings 
Throughout Winthrop, building infrastructure 
includes commercial, residential, institutional, 
and governmental facilities. Public buildings 
include schools, municipal offices, an 
emergency operations center, library, public 
works facilities, fire and police stations, and 
the U.S. Post Office. Many of these buildings 
are in the central business district, which is 
elevated approximately 30 feet above the 
Winthrop shoreline, and are out of projected 
flood areas. Buildings at lower elevations may 
be susceptible to flood impacts. 
Transportation 
Winthrop’s transportation infrastructure 
includes a network of roads and maritime 
facilities that are critical for the regional 
movement of people, equipment, and goods. 
Roadways are vital for the Town, as nearly 
80% of working residents commute outside 
of Winthrop daily. By contrast, few commute 
into Town, with 70% of local jobs filled by 
Winthrop residents. Damage to roadway 
networks due to coastal flooding would have 
significant economic, social, and emergency 
response impacts. 
Road 
The road network in Winthrop includes a 
combination of numbered highways (Route 
145), major local collectors (e.g. Main Street, 
Revere Street, Winthrop Shore Drive), and 
minor local arterials (e.g. Highland Avenue, 
Lincoln Street). 
To access the town, vehicles travel via Route 
145, o Winthrop Parkway or across the Belle 
Isle Bridge (Main Street). Winthrop Parkway 
connects the town to Revere along a narrow 
strip of land between the Belle Isle Marsh and 
How are roads vulnerable to 
coastal flooding? 
Flood water can make roadways 
unpassable to automobile traffic. 
Typically, when there are 4- to 
6-inches of water on the surface, 
drivers are hesitant to cross. The force 
from flood waters can also destroy 
roadway pavement and lead to 
washouts. Sea level rise will result 
in higher groundwater elevations, 
which could flood the roadbed 
and lead to road collapse. Bridges 
and culverts are also vulnerable to 
flood damage. As the depth and 
strength of flood waters increase, 
the streambed surrounding these 
structures can erode or wash out, 
causing damage or collapse.

4-4 IDENTIFY: Critical Public Infrastructure 
scale, coastal flooding also has the potential 
to impact the primary travel route to the 
MWRA’s Deer Island Sewage Treatment Plant 
(treating wastewater from 2.5 million people 
in the Greater Boston area), where 300-500 
personnel provide 24-hour operations and 
maintenance. 
Broad Sound. The Belle Isle Bridge, at the 
western end of Main Street, crosses the Belle 
Isle Inlet, connecting Winthrop to East Boston. 
This bridge was replaced in 2013 to address 
the poor condition of the structure. 
The Massachusetts Bay Transportation 
Authority’s (MBTA) Paul Revere 
Transportation Bus Service serves the 
community with approximately 90 stops 
throughout Winthrop, divided between two bus 
routes. These routes also connect to MBTA’s 
Blue Line Orient Heights Station, which is 
located ½ mile west of the Winthrop/East 
Boston border. From this station, riders can 
travel west to Boston (Bowdoin Station) or 
north to Revere (Wonderland Station). In 2013, 
nearly 500,000 riders used the 712 and 713 
MBTA Paul Revere Bus Service. Including 
both the Paul Revere Bus Service and MBTA 
Blue Line, roughly 20% of Winthrop residents 
use public transportation to commute to work. 
(Winthrop, 2005) 
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. On a regional 
Town Landing, today 
Winthrop Road Infrastructure 
Hig H land 
a ve 
Reve R e St 
Main St 
Wint HR op 
S H o R e d R 
l incoln St 
145 
145 
145 
BROAD SOUND 
CRYSTAL COVE 
BELLE ISLE 
MARSH

4-5 IDENTIFY: Critical Public Infrastructure 
How is maritime 
infrastructure vulnerable to 
coastal flooding? 
A significant storm event could 
cause considerable damage 
to maritime infrastructure. An 
increased frequency of storms could 
compromise structural integrity 
over time. At Town Landing, waves 
could overtop the stone revetment, 
damaging the harbormaster’s 
building and parking area. Flooding 
could also result in inland debris 
entering Crystal Cove, which would 
impair mobilization of emergency 
response watercraft. 
Maritime 
Public maritime infrastructure in Winthrop 
includes several small boat ramps, a mooring 
field in Crystal Cove, with space for 800-900 
recreational boats, and the Winthrop Town 
Landing. 
The Town Landing is the only public maritime 
facility in Winthrop. Located on Shirley Street, 
the facility includes a marina, boat ramp, pier, 
and the harbormaster’s office. Public services 
at the marina include boat slips, a pump-out 
station, and a davit crane. The town landing 
was built on tidelands (previously submerged), 
filled sometime in the mid-1900s. The stone 
revetment protection wall along the shoreline 
has been recently repaired. 
Charter boats can use Town Landing as a pick- 
up and drop-off location. The boat ramp in 
this location is used as an operating center for 
emergency vehicles, such as the harbormaster 
patrol boats and the Winthrop Fire Boat. In the 
winter, the Town Landing parking lot holds 
cars, typically parked on the street, during a 
Snow Emergency Parking Ban. 
The pier at Town Landing serves the Winthrop 
Ferry, which provides commuter services 
to Rowes Wharf in Boston. Implemented 
in November 2015, the ferry also provides 
access to Georges Island and Lovells Island, 
two of the Boston Harbor Islands managed 
by the National Park Service. The ferry runs 
from May to October, during peak commute 
times, with limited weekend service. The 2001 
Winthrop Commuter Boat Feasibility Study 
found that most riders would travel either from 
homes in Winthrop to downtown Boston, or 
from South Shore residences to work at the 
Deer Island Sewage Treatment Plant. 
Town Landing area, in the 1930s 
Source: Winthrop Historical Commission 
(www.facebook.com/ Winthrop-Historical- 
Commission-1482925941926459/

4-6 IDENTIFY: Critical Public Infrastructure 
Water and Wastewater 
Water and wastewater systems in Winthrop 
are owned by the Department of Public Works 
(DPW) Water Division and Massachusetts 
Water Resources Authority (MWRA). 
The Town and MWRA-owned and maintained 
water tower holds roughly 1 million gallons 
of water for several communities served by 
the MWRA. The tower is located on Faunbar 
Avenue in the Cottage Hill neighborhood and 
is a major landmark seen around town and 
beyond. The tower sits on the eastern edge of 
the hill, roughly 120 feet above sea level, and 
is vulnerable to coastal erosion that has been 
reducing the land area adjacent to the tower. 
Sewer pumping stations within Winthrop are 
located at Revere Street, Pico Avenue, and 
Pleasant Court. Recently updated, the stations 
are elevated, well-constructed structures, with 
water resistant flood panels. There are also 
emergency generators located at each pump 
station. 
Massachusetts Water Resources Authority 
(MWRA) owns and maintains over two 
miles of 24-inch diameter sewer main, which 
channels sewage from the Revere town 
boundary through Winthrop for treatment 
at the Deer Island Sewage Treatment Plant. 
Another 108-inch MWRA main through town 
Air 
The eastern shore of Boston Logan 
International Airport, managed by the 
Massachusetts Port Authority (Massport), 
is within Winthrop town boundaries. 
Approximately 900 Winthrop residents work at 
the facility (MAPC and CTPS, 2004). 
Massport prepared a Disaster Infrastructure 
Resiliency Plan (DIRP) in 2014/2015 
How is the water and 
wastewater system 
vulnerable to coastal 
flooding? 
Erosion and transportation 
infrastructure washout could have 
secondary impacts on underground 
piping systems. Rising sea levels and 
the consequent rising groundwater 
elevations could also cause soils 
to shift, particularly at boundaries 
between different soil types. 
Movement and loss of soil strength 
places stress on pipes and joints, and 
can cause significant damage. 
including a hazard analysis of sea level rise 
and storm surge, and recommendations for 
short-term adaptation strategies. Additionally, 
the Critical Assets Resiliency Report in 2014, 
developed concept and operation plans for 
the airport facilities. This assessment does not 
address Logan Airport given Massport’s efforts 
to improve and protect its infrastructure from 
coastal flooding. 
directs sewerage from East Boston to Deer 
Island. The 108-inch main was built in 1891 
and plays a vital role in wastewater treatment 
for 43 communities and 2.5 million people 
(Baldwin, 2006). Entering the town at the 
Belle Isle Bridge, the pipeline to Deer Island 
through Winthrop is nearly three miles long. 
The underlying issue of this critical sewage 
line is its location within floodplain areas and 
the condition of the pipeline. Analyzation of 
the line is currently underway to comprehend 
what is needed to update/reconstruct the 
pipeline

4-7 IDENTIFY: Critical Public Infrastructure 
BROAD SOUND 
CRYSTAL COVE 
BELLE ISLE 
MARSH 
BOSTON 
HARBOR 
Outfalls with check valves at Tafts Avenue 
Stormwater 
The stormwater system within Winthrop 
includes over 20 miles of underground 
piping, outfalls, catch basins, and manholes. 
Approximately 115 outfalls are installed 
throughout the Town in low-lying areas to help 
relieve inland flooding during storm events. 
The majority of these outfalls do not have 
check valves to block water from the ocean 
from entering the system at the headwalls. 
How is the stormwater 
system vulnerable to 
coastal flooding? 
When a heavy storm or tidal event 
occurs, the Town’s drainage systems 
can fill up and cause flooding at 
the street level. Future sea level 
rise and storm events will worsen 
flooding conditions by increasing 
the volume of water to the system 
and blocking outfall locations. Like 
other underground utilities, erosion 
and transportation infrastructure 
washout, and movement and loss 
of soil strength can cause significant 
damage to stormwater pipelines. 
Winthrop Stormwater Infrastructure

4-8 IDENTIFY: Critical Public Infrastructure 
Natural Resources and Open 
Space 
Winthrop offers many beaches, conservation 
areas, parks, and recreation facilities to 
the public. The Town owns many of these 
resources, with exception of Belle Isle Marsh 
and Winthrop Shore Reservation, which 
are publicly owned and managed by the 
Massachusetts Department of Conservation 
and Recreation (DCR). 
Beaches: 
Winthrop Beach – Approximately 1 mile 
long, Winthrop Beach is the Town’s largest 
beachfront resource. Owned by the DCR, 
Withrop Beach provides vital wildlife habitat, 
shoreline protection, and coastal beauty that 
attracts residents and brings visitors to Town. 
Yirrell Beach – As a Town-owned resource, 
Yirrell Beach stretches for about 0.7 miles 
along the eastern coast of Point Shirley. Yirrell 
Beach acts as not only a shoreline protection, 
but as another recreational open space for 
residents to enjoy. 
Donovan’s Beach – Located across Pleasant 
Street from Ingleside Park, Town-owned 
Donovan’s Beach gives Winthrop residents 
waterfront access and beautiful sunset views of 
the City of Boston. It also provides shoreline 
protection from the Boston Harbor during 
coastal flooding events. 
Pico Playground & Beach –Located adjacent 
to Fishermen’s Bend Marsh, the Pico 
Playground and Beach are Town-owned 
recreational facilities. At approximately 0.7 
acres, these resources give the public access to 
Snake Island and Crystal Cove. 
Yirrell Beach 
Salt Marsh: 
Fishermen’s Bend – Owned by the Town, 
Fishermen’s Bend contains a salt marsh and 
public access paths. At approximately 7.5 
acres, the marsh currently provides protection 
to residential properties during flooding events 
such as the King Tide. 
Belle Isle Marsh – Encompassing around 250 
acres of salt marsh and tidal flats, the Belle 
Isle Marsh provides an array of recreational 
and ecological services. As a DCR-owned 
property, and shared between the communities 
of Revere, East Boston, and Winthrop, the 
Belle Isle Marsh contains various walking 
paths and conservation habitats that serve as 
integral components of Winthrop’s community. 
The salt marsh provides habitat to species such 
as the piping plover, upland sandpiper, cord 
grass, and seabeach needlegrass, enhancing 
ecological diversity.

4-9 IDENTIFY: Critical Public Infrastructure 
(Photo by Winthrop Parks Committee https:// 
winthropparks.wordpress.com/) 
Parks: 
Lewis Lake/Winthrop Golf Club – Located in 
the center of Winthrop, Lewis Lake and the 
Winthrop Golf Club serve as vital recreational 
assets for the Town. These Town-owned 
resources play an important economic role 
within the Town, as visitors and residents 
frequent the open space, including walking 
paths and a 9-hole golf course. 
Coughlin Park – Renovated in 2014, Town- 
owned Coughlin Park provides a range of 
recreational resources for Winthrop residents. 
It contains a playground, sports facilities, and 
waterfront amenities. 
Ingleside Park – At around 10 acres, Ingleside 
Park serves as a hub for Winthrop recreational 
and community activities. Owned by the 
Town, this park includes a playground, skating 
rink, picnic areas and other sports facilities. 
Ingleside is a crucial part of Winthrop’s open 
space, as it is located within the center of the 
town and can host many public events and 
sports activities. 
How are natural resources 
vulnerable to coastal 
flooding? 
Coastal flooding and higher 
groundwater elevations have the 
potential to permanently damage 
hard and natural surfaces. Beaches 
and coastal wetlands provide 
ecological benefits including flood 
protection, absorption of pollutants, 
and habitat for fish and shellfish 
(Bosma et. al., 2014). Coastal erosion 
and sea level rise will diminish these 
resources, which are crucial to 
community health and safety.

4-10 IDENTIFY: Critical Public Infrastructure 
Energy 
Winthrop’s energy infrastructure includes 
facilities for energy production, transmission, 
storage, and distribution. Facilities include 
substations, electric lines and street lights, and 
natural gas systems. 
National Grid supplies Winthrop with electric 
power. The company manages two power 
substations within town. Beginning in 2009, 
National Grid conducted an extensive, three 
phase project that upgraded and connected 
the two substations to ensure future service 
reliability for residents. New equipment, 
connection lines and distribution lines were 
installed in both locations, primarily on 
preexisting utility poles (Domelowicz, 2011). 
Natural gas service is also supplied by 
National Grid via underground lines. 
Telecommunications 
Comcast cable currently provides 
telecommunication services to the Town of 
Winthrop. 
Five communication towers within Winthrop 
are located at: 
• Public Safety Communication Tower at 
Faunbar Avenue 
• Cell tower at United Methodist Church 
• Cell tower at Fellows hall 
• Cell tower at St. Johns the Evangelist 
Church 
• Cell tower at the Expert Auto 
How is energy infrastructure 
vulnerable to coastal 
flooding? 
Substation facilities and power 
distribution lines are vulnerable to 
roadway erosion/washout which 
can cause service interruptions or 
considerable damage to equipment. 
Increased flooding and groundwater 
levels also have the potential to 
threaten this infrastructure which 
can cause public health and 
environmental hazards. 
How is telecommunication 
infrastructure vulnerable to 
coastal flooding? 
Telecommunication systems are 
susceptible to failure or destruction 
due to increased flooding and 
groundwater levels. These conditions 
can weaken foundations that 
support overhead poles and expose 
underground conduits to increased 
water and salinity levels. Prolonged 
inundation could compromise short 
term and long term system integrity 
and function, and reduce the overall 
lifespan of system components (e.g. 
sheathing and cabling).

5-1 IDENTIFY: Likely Flood Areas in Winthrop 
5 Flooding can arise from multiple factors. 
Coastal flooding occurs along tidal waterways 
due to winds, waves, storm surge, and tides. 
Inland sources contribute to flooding from 
stormwater runoff, overflows of natural or 
structured drainage systems, and/or rising 
water table levels. It is important to understand 
the relationship between these systems to get 
a complete view of flooding issues within 
a community. However, the purpose of this 
assessment is to specifically focus on the 
protection of assets and areas most at risk from 
the coastal effects of storm surges and sea level 
rise, or coastal flooding. Therefore, there may 
be areas within Town that flood during heavy 
precipitation events that are not predicted to 
occur based on this assessment. 
Although Winthrop’s entire 8.3 mile coastline 
is vulnerable to coastal flooding, evaluating 
the results of the Boston Harbor Flood Risk 
Model (BH-FRM) brings to attention eight 
larger, regional flood areas. These highlighted 
locations (Figure 5-1) are already known to 
flood during coastal storms. The eight BH- 
FRM Flood Areas in Winthrop include: 
• Belle Isle Marsh 
• Nahant Avenue 
• Winthrop Beach 
• Lewis Lake 
• Point Shirley 
• Fishermen’s Bend Marsh 
• Ingleside Park 
• Girdlestone Road 
IDENTIFY: Likely Flood Areas 
in Winthrop 
The following pages assess each area 
by reviewing current conditions, recent 
initiatives, and BH-FRM mapping. This will 
help to further prioritize identified public 
infrastructure (Chapter 6 ) and recommend 
potential adaptation measures (Chapter 7 ) to 
address coastal flooding. 
Figure 5-1 Town-Identified Areas of Local 
Flooding 
REVERE 
DEER 
ISLAND 
BELLE ISLE 
MARSH 
NAHANT AVE 
WINTHROP 
BEAHCH 
LEWIS LAKE 
FISHERMEN'S 
BEND MARSH 
INGLESIDE PARK 
GIRDLESTONE 
ROAD 
POINT 
SHIRLEY

5-2 IDENTIFY: Likely Flood Areas in Winthrop 
Revere Street Sewer Pump Station and 
Pressure Reducing Valve Station 
Short Beach Creek at Belle Isle Marsh 
Winthrop Avenue, view toward Upland Road 
Belle Isle Marsh 
The Belle Isle Marsh is located at the northern 
end of Winthrop, and is also bordered by East 
Boston and Revere. This natural resource is 
owned and managed by the Department of 
Conservation and Recreation, as well as the 
towns of Winthrop and Revere. This nearly 
300 acre salt marsh is one of the largest 
remaining in the Metropolitan Boston area. 
Habitats within the area include salt marsh, a 
tidal creek, salt pans, and upland park land. 
The area is home to a large list of bird species, 
including State-listed species of Endangered, 
Threatened, or Special Concern status. 
As shown in Table 5-1 , the area of flooding 
in Winthrop, adjacent to the marsh, contains 
a range of land uses and several public 
infrastructure points.

5-3 IDENTIFY: Likely Flood Areas in Winthrop 
Table 5-1 Flood Area Existing Conditions – Belle Isle Marsh 
LAND USES 
Mostly residential, with some industrial business on Argyle 
Street and commercial properties near the Belle Isle Bridge, 
natural resources & open space 
ASSOCIATED WATERBODIES Boston Harbor & Belle Isle Inlet 
PUBLIC SHORELINE STRUCTURES 
Stone revetment (<5 feet high) along Morton Street from 
Fairview Street to the Town Cemetery 
5- to 10-foot stone revetment, below the Town Cemetery 
5- to 10-foot bulkhead/seawall at Short Beach 
10- to 15-foot stone revetment along Seawall Avenue 
PUBLIC BUILDINGS 
Pleasant Court Sewer Pump Station 
Revere Street Sewer Pump Station 
Pressure Reducing Valve Station at Revere Street 
TOTAL BUILDINGS 240 
TRANSPORTATION 
INFRASTRUCTURE 
Belle Isle Bridge to East Boston 
Winthrop Parkway Land Bridge to Revere 
Main Street, Pleasant Street, Morton Street & other local 
roadways 
Winthrop Harbor Walk & Eco Park 
WATER AND WASTEWATER 
INFRASTRUCTURE 
Pleasant Court Sewer Pump Station 
Winthrop Parkway Sewer Pump Station 
Underground local and MWRA sewer mains 
Pressure Reducing Valve Station at Revere Street 
STORMWATER INFRASTRUCTURE Underground system, catch basins, and outfalls 
ENERGY INFRASTRUCTURE Argyle Street Substation 
Electric & natural gas distribution system 
TELECOMMUNICATIONS 
INFRASTRUCTURE Cable and telephone lines 
NATURAL RESOURCES & OPEN 
SPACE 
Belle Isle Marsh 
Short Beach 
Fort Banks Playground 
Kilmartin trail and footbridge

5-4 IDENTIFY: Likely Flood Areas in Winthrop 
Considering the vulnerable low-lying land 
within this flood area, many residences, 
businesses, and facilities near the marsh will 
become more susceptible to inundation from 
sea level rise and coastal storms over the next 
15 years. The BH-FRM mapping suggests that 
intense storm events in 2030 may push enough 
water into the marsh to flood Main Street by 
six inches. 
Table 5-2 Probable Future Flooding – Belle Isle Marsh 
SIZE OF FLOOD AREA 
Today: 95 Acres (9% of Winthrop) 
2030: 106 Acres (10% of Winthrop) 
2070: 135 Acres (13% of Winthrop) 
TOWN-IDENTIFIED 
FLOOD AREAS / ISSUES 
Bayou Street Neighborhood – undersized drainage line backs up in 
high precipitation events (HMP, 2014) 
CURRENT INITIATIVES 
/ CONSTRUCTION 
PROJECTS 
Belle Isle Marsh Marine Ecology Park (path along Morton Street, with 
a passive recreation park, lookout area, footbridge to the Belle Isle 
Cemetery. 
PROBABLE FUTURE 
FLOOD AREAS 
Portions of Argyle Street and Golden Drive 
Morton Street 
Main Street 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2030 FLOOD AREA) 
Pleasant Court Sewer Pump Station 
Main Street 
Stone Revetment, seawalls & bulkheads 
ADDITIONAL CRITICAL 
PUBLIC INFRASTRUCTURE 
(2070 FLOOD AREA) 
Belle Isle Bridge 
Argyle Power Substation 
Revere Street Sewer Pump Station 
Pressure Reducing Valve Station at Revere Street 
Winthrop Traffic Control Point at Winthrop Parkway and Revere 
Street 
Winthrop Traffic Control Point at Main Street

5-5 IDENTIFY: Likely Flood Areas in Winthrop 
Nahant Avenue 
The rocky shoreline of this northeastern 
section of Winthrop includes residences along 
Nahant Avenue, and a portion of Grovers 
Avenue and Seawall Avenue. The area is 
entirely residential, with views of Broad Sound 
toward Revere. 
Table 5-3 Flood Area Existing Conditions – Nahant Avenue 
LAND USES Residential 
ASSOCIATED WATERBODIES Broad Sound 
PUBLIC SHORELINE STRUCTURES None 
PUBLIC BUILDINGS None 
TOTAL BUILDINGS 45 
TRANSPORTATION INFRASTRUCTURE Local roadways 
WATER AND WASTEWATER 
INFRASTRUCTURE Local underground lines 
STORMWATER INFRASTRUCTURE Underground system, catch basins, and outfalls 
ENERGY INFRASTRUCTURE Electric and natural gas distribution systems 
TELECOMMUNICATIONS 
INFRASTRUCTURE Cable and telephone lines 
NATURAL RESOURCES & OPEN SPACE Pond Street Playground 
Seawall Avenue looking toward Nahant 
Avenue Flood Area 
Nahant Avenue properties have a high 
water table

5-6 IDENTIFY: Likely Flood Areas in Winthrop 
The coastline here is vulnerable to flooding 
from a combination of high groundwater, tidal 
surge, and high precipitation. During a site 
visit on March 23, 2017, water was observed 
seeping up from the ground at the intersection 
of Nahant and Grovers Avenues. Anecdotal 
information was provided from a resident at 
the first Public Meeting, noting that homes in 
this area are almost always operating pumps 
to remove water from their basements. The 
2014 update of the Town’s Hazard Mitigation 
Plan identifies two homes as repetitive loss 
properties by the FEMA National Flood 
Insurance Program. The 2030 BH-FRM shows 
that homes in this area could see about ½ to 
one foot of flooding during a 1% chance water 
surface elevation. 
Table 5-4 Probable Future Flooding – Nahant Avenue 
SIZE OF FLOOD AREA 
Today: 4 Acres (<1% of Winthrop) 
2030: 8 Acres (1% of Winthrop) 
2070: 23 Acres (2% of Winthrop) 
TOWN-IDENTIFIED 
FLOOD AREAS / 
ISSUES 
Undersized drain lines fill up and flood the neighborhood during 
coastal storms and high tide (MAPC, 2014) 
CURRENT INITIATIVES 
/ CONSTRUCTION 
PROJECTS 
2014 Hazard Mitigation Plan identified replacing the undersized 
drainage line and upgrading the existing drainage outfall headwall 
and installing a flapper valve as priority mitigation measures for this 
area. 
BH-FRM MAPPED 
FLOOD AREAS (2030- 
2070) 
Upland Road 
Seawall Avenue, from Upland Road to Highland Avenue 
Nahant Avenue, through Highland Avenue, and Pond Street 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2030 FLOOD AREA) 
None 
ADDITIONAL 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2070 FLOOD AREA) 
None

5-7 IDENTIFY: Likely Flood Areas in Winthrop 
Winthrop Beach 
The Winthrop Beach flood area, located on 
the eastern shore of town, is a combination 
of public facilities, private homes, and 
commercial properties. The barrier beach is 
owned and operated by the Massachusetts 
Department of Conservation and Recreation 
(DCR), and provides community benefits like 
storm protection, recreation, and tourism. 
Shoreline sandbar/breakwater structures at 
Winthrop Beach 
Table 5-5 Flood Area Existing Conditions 
– Winthrop Beach 
LAND USES Residential, commercial, natural resources & open 
space, recreational property (State-owned beach) 
ASSOCIATED WATERBODIES Broad Sound 
PUBLIC SHORELINE STRUCTURES 
Stone mound groins at Charles Street, Beacon Street, 
Wave Way, Coral Avenue, Neptune Avenue 
5- to 15-foot seawall & stone revetment along 
Winthrop Shore Drive 
Five Sisters (15 feet +) 
PUBLIC BUILDINGS None 
TOTAL BUILDINGS 670 
TRANSPORTATION INFRASTRUCTURE Local roadways 
WATER AND WASTEWATER 
INFRASTRUCTURE Local underground lines 
STORMWATER INFRASTRUCTURE 
Underground MWRA sewer main and water line 
Local underground utility lines 
Pressure Reducing Valve Station at Underhill Street 
ENERGY INFRASTRUCTURE Electric and natural gas distribution systems 
TELECOMMUNICATIONS 
INFRASTRUCTURE Cable and telephone lines 
NATURAL RESOURCES & OPEN SPACE Winthrop Shore Beach

5-8 IDENTIFY: Likely Flood Areas in Winthrop 
Table 5-6 Probable Future Flooding– Winthrop Beach 
SIZE OF FLOOD AREA 
Today: 86 Acres (8% of Winthrop) 
2030: 88 Acres (9% of Winthrop) 
2070: 91 Acres (9% of Winthrop) 
TOWN-IDENTIFIED FLOOD 
AREAS/ISSUES 
Ocean winds and waves overtop the seawalls during coastal 
storm events, flooding Winthrop Shore Drive, adjacent roadways, 
and residential properties. 
CURRENT INITIATIVES / 
CONSTRUCTION PROJECTS 
DCR has designed and constructed a beach nourishment 
project and repairs to shoreline structures. Construction of a 
streetscape project, including drainage improvements along 
Winthrop Shore Drive, is scheduled to begin this year. 
BH-FRM MAPPED FLOOD 
AREAS (2030-2070) 
From Winthrop Beach in the east to Shirley Street at the west 
From Veterans Road in the north, to Crystal Cove Avenue at the 
south 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2030 FLOOD AREA) 
Shirley Street & Tafts Avenue (Route 145) - evacuation/trucking 
route 
Regional sewer main 
Pressure Reducing Valve Station at Underhill Street 
ADDITIONAL CRITICAL 
PUBLIC INFRASTRUCTURE 
(2070 FLOOD AREA) 
None 
The topography of the Winthrop Beach Flood 
Area slopes from Winthrop Shore Drive down 
to Shirley Street. Since the early 1900s, the 
Commonwealth has made many efforts to help 
reduce coastal flooding behind the beach. 
The 2030 BH-FRM model calculates that there 
is potential for extreme coastal storm events to 
flood the area between Winthrop Shore Drive 
and Shirley Street to approximately 1-foot 
deep. A significant amount of flooding in this 
area is caused by wave run-up and overtopping 
(see above photo). Coastal storm waves will 
pulse volumes of water landward and flow 
through the Winthrop Beach infrastructure 
towards Lewis Lake.

5-9 IDENTIFY: Likely Flood Areas in Winthrop 
Storm protection
berm completed
Beach nourishment
at north end
Construction
of three
breakwaters
(“Sisters”)
Structural repairs to
three groins at south
end of beach 
2015
2013
2014
1930
2012
1959 
Beach restoration at south end,
with sand accreted behind Five
Sisters breakwaters
Two breakwaters added
(“Five Sisters”)
Sand placed in between Sisters
to replenish the beach.
Groins and revetment installed.
Sea walls raised and/or capped. 
Figure 5-2 Timeline of Storm Structure Construction along Winthrop Beach 
1932 storm along Winthrop Shore Drive, Courtesy of the Boston Public 
Library, Leslie Jones Collection.

5-10 IDENTIFY: Likely Flood Areas in Winthrop 
Lewis Lake 
Before the construction of a steam railroad 
loop and construction of Washington Street in 
the late 19 th century, Lewis Lake was a small 
tidal stream, known as Fisher’s Creek, with 
adjacent marshland (MHC, 1981). Due to the 
history here, infrastructure in this flood area 
has been developed on what would historically 
have been salt marsh. 
The Town of Winthrop owns much of the land 
in this central area of the community: Lewis 
Lake Park and Daw Playground, the Golf Club 
property, and Winthrop High School athletic 
fields. In addition to these public recreational 
and institutional properties, the fringes of 
the Lewis Lake flood area include residential 
and commercial land uses. Important public 
infrastructure includes Route 145 (Washington 
Avenue and Veterans Road) and the Beach Fire 
Station which are vital to the Town’s security 
and safety. 
Winthrop High School 
Shirley Street Fire Station

5-11 IDENTIFY: Likely Flood Areas in Winthrop 
Table 5-7 Flood Area Existing Conditions - Lewis Lake 
LAND USES 
Athletic fields/parks, natural resources, residential, waterfront, a 
large amount of open space, neighborhoods, small businesses, high 
school, golf club, cemetery 
ASSOCIATED 
WATERBODIES Crystal Cove - Lewis Lake - Broad Sound 
PUBLIC SHORELINE 
STRUCTURES Lewis Lake Tide Gate 
PUBLIC BUILDINGS Beach Fire Station 
Winthrop High School 
TOTAL BUILDINGS 440 
TRANSPORTATION 
INFRASTRUCTURE 
Shirley Street, Tafts Avenue (Route 145) and Veterans Road are 
evacuation and trucking routes 
WATER AND 
WASTEWATER 
INFRASTRUCTURE 
Underground MWRA sewer main and water line 
Local underground lines 
Pressure Reducing Valve Station at Underhill Street 
STORMWATER 
INFRASTRUCTURE 
Lewis Lake is a major catchment area for the town 
Drainage swale recently installed / cleared out around perimeter of 
golf course 
Undergroud system, catch basins, outfalls 
ENERGY 
INFRASTRUCTURE 
Electric transmission and distribution system 
Natural gas distribution system 
TELECOMMUNICATIONS 
INFRASTRUCTURE Cable and telephone lines 
NATURAL RESOURCES & 
OPEN SPACE 
Lewis Lake (including Norman F. Daw Playground and section of 
Winthrop Harborwalk) 
High School Stadium and ball fields 
Golf Club

5-12 IDENTIFY: Likely Flood Areas in Winthrop 
The area surrounding Lewis Lake experiences 
flooding due to the build-up of silt in Lewis 
Lake, which decreases the ability of the Lake 
to properly drain (MAPC, 2014). The 2014 
update of the Town’s Hazard Mitigation 
Plan identifies three single family homes 
and two multi-family buildings as repetitive 
loss properties by the FEMA National Flood 
Insurance Program. 
Where the Lewis Lake Flood Area and the 
Winthrop Beach Flood Area meet, (in the 
vicinity of Shirley Street,) they are both likely 
to contribute to flooding (around 50 structures 
are partially in both flood areas). Lewis Lake 
is also a major catchment area, collecting 
stormwater from approximately 1/2 of the 
community. It is recommended that these 
occurrences are studied holistically, so that 
an appropriate approach to resiliency may be 
taken. 
Winthrop Golf Course Drainage at Veterans 
Road 
Table 5-8 Probable Future Flooding – Lewis Lake 
SIZE OF FLOOD AREA 
Today: 140 Acres (14% of Winthrop) 
2030: 153 Acres (15% of Winthrop) 
2070: 165 Acres (16% of Winthrop) 
TOWN-IDENTIFIED FLOOD 
AREAS/ISSUES 
Lewis Lake is a critical stormwater storage area (drains half of 
town). Lake overflows during storm events, causing flooding in 
surrounding area (HMP, 2014) 
CURRENT INITIATIVES 
/ CONSTRUCTION 
PROJECTS 
Drainage improvements along Veterans Road 
Drainage swale around Golf Club perimenter 
Lewis Lake Tide Gate 
BH-FRM MAPPED FLOOD 
AREAS (2030-2070) 
From Crystal Cove to Revere Street – Shirley Street – Bowdoin Street 
in the north 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2030 FLOOD AREA) 
Evacuation/trucking route 
Regional sewer main 
Beach Fire Station 
ADDITIONAL CRITICAL 
PUBLIC INFRASTRUCTURE 
(2070 FLOOD AREA) 
None

5-13 IDENTIFY: Likely Flood Areas in Winthrop 
Point Shirley 
Land use within the Point Shirley Flood Area 
includes residential properties, commercial, 
and recreational facilities. Sandwiched 
between the Boston Harbor on the west and 
Broad Sound to the east, many residences 
within the area are regularly exposed to 
inundation and wave action. 
On the harbor side, Coughlin Park includes 
a salt marsh, tidal flats and beach area. The 
park offers recreational facilities including 
basketball courts, water access, and walking 
trails. The shoreline wraps around a cove area 
called “The Basin” to the Winthrop Town 
Landing. Town Landing is also identified as 
critical public infrastructure, as it includes a 
public boat ramp and ferry service to Boston. 
Located on Shirley Street, across the Basin 
from Coughlin park, Town Landing was built 
on filled tideland in the mid-20 th century. 
Between Coughlin Park and Town Landing are 
approximately 50 privately-owned properties. 
Yirrell Beach 
MBTA Paul Revere Bus at Shirley Street 
Other important public infrastructure 
includes the Pressure Reducing Valve Station 
at Bayview Avenue and Winthrop Town 
Landing. Point Shirley, via Shirley Street 
and Tafts Avenue, is also the key access 
route for emergency equipment to reach the 
neighborhood and the Deer Island Sewage 
Treatment Plant. Prolonged flooding of 
these roadways could have negative social, 
environmental, and economic impacts.

5-14 IDENTIFY: Likely Flood Areas in Winthrop 
Table 5-9 Flood Area Existing Conditions – Point Shirley 
LAND USES High Density and Multi-Family Residential, natural resources and 
open space, commercial, marina 
ASSOCIATED WATERBODIES Broad Sound, Boston Harbor 
PUBLIC SHORELINE 
STRUCTURES 
10- to 15-foot stone revetment at Town Landing 
5- to 10-foot seawall/revetment along Shirley Street (adjacent 
to Town Landing) 
5- to 10-foot seawall from the top of Yirrell Beach to Petrel Street 
5- to 10-foot bulkhead/seawall/revetment along Grand View 
Avenue (Shirley Street to north of Deep Water Street) 
10- to 15-foot stone revetment along Grand View Avenue (from 
Bayview Ave to south of Foam Street) 
PUBLIC BUILDINGS None 
TOTAL BUILDINGS 545 
TRANSPORTATION 
INFRASTRUCTURE Shirley Street to Tafts Avenue / local roadways 
WATER AND WASTEWATER 
INFRASTRUCTURE Sewer main to Deer Island 
STORMWATER 
INFRASTRUCTURE Underground system, catch basins, outfalls 
ENERGY INFRASTRUCTURE Electric transmission and distribution system 
Natural gas distribution system 
TELECOMMUNICATIONS 
INFRASTRUCTURE Cable and telephone lines 
NATURAL RESOURCES & 
OPEN SPACE Yirrell Beach 
The 2014 Winthrop Hazard Mitigation Plan 
identified Point Shirley as the most frequently 
flooded area of Winthrop. The flat and narrow 
areas of this flood zone make it susceptible to 
storm surges and waves from the ocean, and 
additional flooding from Boston Harbor. High 
water levels measured after the Blizzard of 
1978 were recorded at elevation 12.67 feet at 
Elliot Street (existing elevation at this site is 
about 10 feet). 
During northwest winds and coastal storms, 
Coughlin park faces coastal erosion and 
inundation. The Town has completed a 
feasibility assessment to evaluate design 
installations that could help slow the erosion. 
The process has identified green infrastructure 
along the western shoreline as the best 
alternative to increase coastal resilience of the 
park. 
The coastal flood modeling for this area 
estimates that the Point Shirley Association (on 
the corner of Shirley Street and Pebble Ave) 
could experience around a foot of flooding 
during a 1% chance water level in 2030. The 
same location and storm could see four feet of 
water during a severe storm in 2070.

5-15 IDENTIFY: Likely Flood Areas in Winthrop 
Table 5-10 Probable Future Flooding – Point Shirley 
SIZE OF FLOOD AREA 
Today: 84 Acres (8% of Winthrop) 
2030: 88 Acres (9% of Winthrop) 
2070: 90 Acres (9% of Winthrop) 
TOWN-IDENTIFIED FLOOD 
AREAS/ISSUES 
Point Shirley is the most frequently flooded area in town. 
Area is subject to decreased sediment, coastal erosion, 
and shoreline change. 
Existing seawall at Yirrell Beach is occasionally breached, 
and doesn’t cover area between Wyman Street to Deer 
Island. Local efforts have been made for protection and 
repairs, but this area remains a top priority for flooding 
mitigation. Area is subject to decreased sediment, coastal 
erosion, and shoreline change. 
Coughlin Park experience coastal erosion and flooding 
during higher northwest wind events and coastal storms. 
Area is also subject to decreased sediment and shoreline 
change. 
CURRENT INITIATIVES / 
CONSTRUCTION PROJECTS 
Grandview Avenue seawall was upgraded and heightened 
by two feet from Billows Street to Coughlin Playground 
Drainage pipelines have been enlarged along Shirley Street 
and Tafts Avenue to increase the stormwater capacity of 
the system. 
BH-FRM MAPPED FLOOD AREAS 
(2030-2070) 
All of Point Shirley, with exceptions of the highest elevation 
around Unding Avenue 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2030 FLOOD AREA) 
Evacuation / trucking route 
Point Shirley Association 
ADDITIONAL CRITICAL PUBLIC 
INFRASTRUCTURE (2070 FLOOD 
AREA) 
None

5-16 IDENTIFY: Likely Flood Areas in Winthrop 
Fishermen’s Bend 
The Fishermen’s Bend Flood Area is primarily 
marsh land. The coastline also includes tidal 
flats, beach and a small dune. These natural 
resources have been acquired by the Town and 
are managed by the Conservation Commission. 
There are walking trails within the marsh, 
and the Pico Playground and Beach provide 
recreational opportunities the surrounding 
neighborhood. Residential properties abutting 
the beach and salt marsh are also included in 
the Fishermen’s Bend Flood Area. 
Pico Avenue Sewer Pump Station 
Entrance to Pico Park 
Sea walls in this area have been previously 
identified for upgrades. The Pico Avenue 
Sewer Pump Station may see 1 ½ feet of 
flooding during a 1% chance water surface 
elevation in 2030, and potentially more than 
four feet in 2070.

5-17 IDENTIFY: Likely Flood Areas in Winthrop 
Table 5-11 Flood Area Existing Conditions – Fishermen’s Bend 
LAND USES Salt marsh & beach, residential, commercial, recreation 
ASSOCIATED 
WATERBODIES Crystal Cove, Boston Harbor 
PUBLIC SHORELINE 
STRUCTURES 
Stone groin at the end of Pico Avenue 
5- to 10-foot seawall/stone revetment along Frances Street 
5- to 10-foot seawall at Woodside Avenue 
PUBLIC BUILDINGS None 
TOTAL BUILDINGS 145 
TRANSPORTATION 
INFRASTRUCTURE Neighborhood Roads 
WATER AND WASTEWATER 
INFRASTRUCTURE Underground system 
STORMWATER 
INFRASTRUCTURE Underground system, catch basins, outfalls 
ENERGY INFRASTRUCTURE Electric transmission and distribution system 
Natural gas distribution system 
TELECOMMUNICATIONS 
INFRASTRUCTURE Cable and telephone lines 
NATURAL RESOURCES & 
OPEN SPACE 
Fishermen’s Bend Marsh 
Pico Park 
Pico Beach 
Table 5-12 Probable Future Flooding – Fishermen’s Bend 
SIZE OF FLOOD AREA 
Today: 30 Acres (3% of Winthrop) 
2030: 35 Acres (3% of Winthrop) 
2070: 43 Acres (4% of Winthrop) 
TOWN-IDENTIFIED FLOOD 
AREAS/ISSUES 
Woodside seawall and headwall experiences coastal surge 
flooding during storm events 
CURRENT INITIATIVES / 
CONSTRUCTION PROJECTS The sewer pump station has backup generation capacity. 
BH-FRM MAPPED FLOOD 
AREAS (2030-2070) 
Crystal Cove to Pleasant Street in the north 
Fishermen’s Bend Marsh to Sunnyside Avenue in the west 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2030 FLOOD AREA) 
Pico Sewer Pump Station 
ADDITIONAL CRITICAL 
PUBLIC INFRASTRUCTURE 
(2070 FLOOD AREA) 
None

5-18 IDENTIFY: Likely Flood Areas in Winthrop 
Ingleside Park 
The Ingleside Park Flood Area stretches 
between Donovan’s Beach on the west side 
of the peninsula, and the Arthur T. Cummings 
Elementary School near the civic center 
of Winthrop. The beach and park are both 
owned by the Town. Many public amenities 
are within the flood area, including access 
to Boston Harbor with views of Boston’s 
skyline, walking trails, athletic fields, tennis 
courts, basketball courts, a skateboard 
park, playground and public skating rink. 
Residences border much of the park perimeter, 
with the Central Business District adjacent to 
the southeast of the flood area. 
On an 1859 “Map of Boston and its Vicinity” 
by Henry Francis Walling, ( Norman B. 
Leventhal Map Center, Boston Public Library ), 
the Ingleside Park area appears as a tidal 
stream and low-lying marsh. William H. 
Clark’s History of Winthrop Massachusetts 
described The area was described as a swamp, 
in the area as swampland and noted that it 
was filled in 1936 with funds from the Public 
Welfare Department (Clark, 1952). 
The flood pathway to Ingleside Park is at 
Donovan’s Beach, likely the same location that 
the tidal stream once entered the swamp. The 
park floods often, (mostly from precipitation 
View of City of Boston from Donovan's Beach 
Pleasant Street 
events,) and anecdotal conversations within 
town noted a couple of buildings within the 
Central Business District run pumps nearly all 
the time. Existing drainage infrastructure is 
being assessed (by others) at Ingleside Park. 
The facility is at sea level, with drain pipe 
discharging at Donovan's Beach. There is a 
valve on the existing outfall that shuts down 
during heavy tides. (MAPC, 2014) 
The coastal flood modeling for this area shows 
that Pleasant Street may be flooded to a depth 
of 8 inches in during a 1% chance water 
surface elevation in 2030, making the roadway 
impassible. The same location and storm could 
see 3.5-feet of water during a severe storm in 
2070.

5-19 IDENTIFY: Likely Flood Areas in Winthrop 
Table 5-13 Flood Area Existing Conditions – Ingleside Park 
LAND USES Civic, school, residential, commercial, natural resources and open 
space 
ASSOCIATED 
WATERBODIES Boston Harbor 
PUBLIC SHORELINE 
STRUCTURES Concrete seawall (<5 feet high) at Donovan’s Beach 
PUBLIC BUILDINGS None 
TOTAL BUILDINGS 150 
TRANSPORTATION 
INFRASTRUCTURE Pleasant Street (Route 145), local roadways, walking trails 
WATER AND WASTEWATER 
INFRASTRUCTURE Underground system 
STORMWATER 
INFRASTRUCTURE Underground system, catch basins, outfalls 
ENERGY INFRASTRUCTURE Electric transmission and distribution system 
Natural gas distribution system 
TELECOMMUNICATIONS 
INFRASTRUCTURE Cable and telephone lines 
NATURAL RESOURCES & 
OPEN SPACE Donovan’s Beach, Ingleside Park 
Table 5-14 Probable Future Flooding – Ingleside Park 
SIZE OF FLOOD AREA 
Today: 28 Acres (3% of Winthrop) 
2030: 37 Acres (4% of Winthrop) 
2070: 65 Acres (6% of Winthrop) 
TOWN-IDENTIFIED FLOOD 
AREAS/ISSUES 
The park is at sea level, and may benefit from a pump station 
(MAPC, 2014) 
CURRENT INITIATIVES / 
CONSTRUCTION PROJECTS 
The Town constructed dikes in the park, around two homes, to 
temporarily reduce flooding in the area (MAPC, 2014) 
BH-FRM MAPPED FLOOD 
AREAS (2030-2070) 
Shoreline from Loring Road Boat Ramp to Lincoln Street 
Ingleside Park area, with potential to cross Pauline Street and 
move southeast along Putnam Street and Woodside Avenue 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2030 FLOOD AREA) 
Pleasant Street 
ADDITIONAL CRITICAL 
PUBLIC INFRASTRUCTURE 
(2070 FLOOD AREA) 
None

5-20 IDENTIFY: Likely Flood Areas in Winthrop 
Girdlestone Road 
The Girdlestone Road Flood Area is north 
of Ingleside Park and south of Main Street. 
The area includes the Pleasant Park Yacht 
Club, Atlantis Marina Condominiums/Boat 
Facilities, and a residential neighborhood. 
Table 5-15 Flood Area Existing Conditions – Girdlestone Road 
LAND USES Private recreation, residential 
ASSOCIATED 
WATERBODIES Boston Harbor 
PUBLIC SHORELINE 
STRUCTURES None 
PUBLIC BUILDINGS None 
TOTAL BUILDINGS 115 
TRANSPORTATION 
INFRASTRUCTURE Pleasant Street (Route 145), neighborhood roads, boat slips 
WATER AND WASTEWATER 
INFRASTRUCTURE Underground system 
STORMWATER 
INFRASTRUCTURE Underground system, catch basins, outfalls 
ENERGY INFRASTRUCTURE Electric and natural gas distribution systems 
TELECOMMUNICATIONS 
INFRASTRUCTURE Cable and telephone lines 
NATURAL RESOURCES & 
OPEN SPACE None 
Pleasant Park Yacht Hall at Belle Isle Pier

5-21 IDENTIFY: Likely Flood Areas in Winthrop 
Flood waters appear to enter the Girldestone 
Road Flood Area at the Pleasant Park 
Yacht Club boat ramp. This area should be 
addressed, as Pleasant Street and the adjacent 
neighborhoos could experience two feet of 
flooding during a 1% chance water surface 
elevation in 2030. 
Table 5-16 Probable Future Flooding – Girdlestone Road 
SIZE OF FLOOD AREA 
Today: 9 Acres (1% of Winthrop) 
2030: 12 Acres (1% of Winthrop) 
2070: 19 Acres (2% of Winthrop) 
TOWN-IDENTIFIED FLOOD 
AREAS/ISSUES None mentioned. 
CURRENT INITIATIVES / 
CONSTRUCTION PROJECTS None 
BH-FRM MAPPED FLOOD 
AREAS (2030-2070) 
Pleasant Street to Beal Street, including Girdlestone Road and a 
portion of Tileston Road 
CRITICAL PUBLIC 
INFRASTRUCTURE 
(2030 FLOOD AREA) 
Pleasant Street (Route 145) evacuation route 
ADDITIONAL CRITICAL 
PUBLIC INFRASTRUCTURE 
(2070 FLOOD AREA) 
None

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6-1 PRIORITIZE: Critical Public Infrastructure 
6 
With critical public infrastructure and the 
likely areas of flooding in town identified, 
the next step in the assessment process is to 
systematically evaluate and prioritize critical 
infrastructure at the Town-wide level. This 
process will enable the Town to make strategic 
and cost-effective investments in the locations 
that are most at risk from coastal flooding. 
PRIORITIZE: Critical Public 
Infrastructure 
Shirley Street at Town Landing

6-2 PRIORITIZE: Critical Public Infrastructure 
Calculating Risk 
There are many different mathematical 
models that can be used to calculate a risk 
score to prioritize infrastructure assets/ 
facilities. For this study, the goal was to use 
a system that was simple to follow and easily 
communicated. 
A five-tier qualitative rating system (assigned 
1 to 5) was developed for determining the 
consequence that flooding would have on any 
given asset. The rating score is multiplied 
by the likelihood that assets may flood under 
present day, 2030, and 2070 scenarios using 
the Boston Harbor Flood Risk Model (BH- 
FRM) results. A weighting factor for the 
probability of flooding is also included in the 
calculation. Assets within present day flood 
areas are given higher weighting than those at 
risk in future years: 
• 60% weighting within the present-day 
flood areas 
• 30% weighting for 2030 
• 10% weighting for 2070. 
The assets/facilities can then be evaluated, in 
order of priority, based on the total score. In 
other words, the higher the score, the higher 
the priority to investigate adaptation measures 
for the infrastructure. 
RISK = 
CONSEQUENCE x 
PROBABILITY

6-3 PRIORITIZE: Critical Public Infrastructure 
Consequence 
The consequence of failure score, calculated 
for each asset/facility, was based on adding 
together individual ratings (1 through 5) for 
each of the following four criticality criteria: 
Winthrop Fire Station 
Shirley Street Neighborhood from Yirrell 
Beach 
Area of Service Loss: Who is 
impacted by the loss of or damage 
to the core functions of the asset? 
Public Safety & Emergency 
Services: How important is the 
asset to community evacuation and 
disaster response operations? 
Social & Economic Activities: 
How important is the asset to 
providing people with access or 
service to their homes and jobs? 
Public Health & Environment: 
How important is the asset to 
controlling human exposure to 
pollutants and secondary impacts 
to the natural environment? 
Probability 
The likelihood of flooding under present 
day, 2030, and 2070 scenarios is based on 
data developed using the BH-FRM. A data 
point was created using geographic 
information systems (GIS) for each 
public infrastructure asset within the BH- 
FRM. Based on a critical elevation at each 
location, an estimated depth of flooding was 
determined where the flood event is likely to 
impair an asset in any given year (a 0.1% to 
100% chance). In some cases, any depth of 
water would put a location at risk, whereas 
other locations can sustain core functions even 
with a few inches of water. The possibility that 
the water depth starts to harm an asset’s core 
functions is calculated into the score. A detailed 
table of this data for each asset is included in 
Appendix G (Probability of Exceedance Curve 
Data extracted from the BH-FRM). 
It is recognized that there is a certain level of 
interpretation or subjectivity applied when 
assigning consequence ratings.

6-4 PRIORITIZE: Critical Public Infrastructure 
Figure 6-1 Prioritized Critical Public Infrastructure in Winthrop 
14 
Washington Avenue 
Shirley Street 
Main Street 
Veterans Road 
Revere Street 
Winthrop 
Shore Drive 
Tafts Avenue 
Winthrop Street 
Pauline Street 
Shirley Street 
Pleasant Street BROAD SOUND 
CRYSTAL 
COVE 
BELLE ISLE 
INLET 
BOSTON HARBOR 
BELLE ISLE MARSH 
REVERE 
DEER 
ISLAND 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
Washington Avenue 
Shirley Street 
Main Street 
Winthrop Shore Drive 
Veterans Road 
Winthrop Street 
Court Road 
Revere Street 
CRITICAL INFRASTRUCTURE 
= Pico Sewer Pump Station 
= Pleasant Court Sewer Pump Station 
= Washington Street 
= Main Street 
= Pleasant Street 
= Beach Fire Station 
= Winthrop High School 
= Pressure Reducing Valve Station (Bayview Ave) 
= Pressure Reducing Valve Station (Underhill St) 
= Shirley Street 
= Public Landing 
= Pressure Reducing Valve Station (Revere St) 
= Revere St. Sewer Pump Station 
= Belle Isle Bridge 
= Power Substation (Argyle St) 
= Loring Rd. Boat Ramp 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16

6-5 PRIORITIZE: Critical Public Infrastructure 
Winthrop’s Critical Public Infrastructure Priorities 
Based on the methodology described above and outlined in more detail in Appendix G , critical 
public infrastructure is prioritized in Table 6-1. 
Table 6-1 Critical Public Infrastructure Risk Scores and Ranking 
RANK CRITICAL INFRASTRUCTURE FLOOD 
AREAS 
CRITICALITY 
TOTAL 
% PROBABILITY OF 
FLOODING 
TOTAL 
RISK 
SCORE PRESENT 2030 2070 
Pico Sewer Pump Station Fishermen's 
Bend 15 5 25 100 307.5 
Pleasant Court Sewer Pump Station Belle Isle 
Marsh 15 2 25 100 280.5 
Washington Street (town evacuation 
route) Lewis Lake 15 2 20 100 258 
Main Street (town evacuation route) Belle Isle 
Marsh 18 0.5 5 100 212.4 
Pleasant Street (town evacuation 
route) 
Ingleside 
Park 15 0.2 5 100 174.3 
Beach Fire Station Lewis Lake 14 1 5 100 169.4 
Winthrop High School Lewis Lake 13 1 5 100 157.3 
Pressure Reducing Valve Station 
(Bayview Ave) Point Shirley 13 1 5 100 157.3 
Pressure Reducing Valve Station 
(Underhill St) 
Winthrop 
Beach 13 0.5 2 100 141.7 
Shirley St (town evacuation/MWRA 
truck route) Point Shirley 20 0.5 10 20 106 
Public Landing Point Shirley 10 0 0.5 50 51.5 
Pressure Reducing Valve Station 
(Revere Street) 
Belle Isle 
Marsh 13 0 0.2 30 39.78 
Revere St. Sewer Pump Station Belle Isle 
Marsh 15 0 0.1 20 30.45 
Belle Isle Bridge Belle Isle 
Marsh 18 0 0 2 3.6 
Power Substation (Argyle Street) Belle Isle 
Marsh 18 0 0 2 3.6 
Loring Rd. Boat Ramp Ingleside 
Park 4 0 0 1 0.4 
The pump station prioritization process emphasizes the importance of focusing on protecting 
wastewater/sewer infrastructure and keeping evacuation/trucking routes open. The next chapters 
will focus on providing adaptation strategies for these types of infrastructure. 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16

6-6 PRIORITIZE: Critical Public Infrastructure 
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7-1 STRATEGIZE: Living with Coastal Waters 
With evacuation routes and water/wastewater 
facilities identified as the Town’s highest 
priority infrastructure in Chapter 6, the next 
step is to strategize how these places may 
become more resilient in the face of sea level 
rise, coastal storm surge, and related coastal 
flooding. 
Before discussing potential resilience 
approaches, there are some important points to 
make: 
1. Adaptation measures will need 
to be implemented over time, in 
coordination with public and private 
partners. The key is to advance 
strategies at all scales, in a coordinated 
manner, to address coastal flooding 
risks in the short term and long term. 
2. No adaptation installation is a 
fail-safe solution as no amount 
of modeling or planning can 
fully predict the future. This is an 
important reality that focuses our 
attention on identifying strategies that 
provide public benefits in the near term 
and are flexible enough to work over a 
range of future conditions. 
» In addition to reducing the effects 
of coastal flooding, adaptation 
measures can include additional 
public benefits such as improved 
public access to the waterfront and 
protection / enhancement of natural 
resources. 
7 STRATEGIZE: Living with Coastal Waters 
Coughlin Park Shoreline. Source: Woods Hole 
Group 
» Flexible approaches that grow 
with sea level rise may include 
adaptable ecological installations, 
natural berms, or other waterfront 
structures that can be adjusted 
vertically in height or expanded 
along the shoreline. 
Clever adaptation strategies that are 
flexible and offer multiple community 
benefits are more likely to gain the 
community and financial support needed 
for implementation.

7-2 STRATEGIZE: Living with Coastal Waters 
3. Once the adaptation measure is 
installed, ongoing support will help 
ensure the installation is successful. 
When selecting an adaptation measure, 
an analysis of alternatives will help find 
the best installation for the community. 
Alternatives should include a variety of 
installation types and consider: 
» Cost - depending on the type, 
quantity, and/or scale of measures 
chosen, they can cost a few 
thousand, or millions of dollars. 
» Operations and maintenance – who 
will design, install, and maintain 
the retrofits? If the installation 
requires pre-storm preparation, who 
will respond to flood warnings? 
Who will manage clean-up efforts 
after the flood? 
» Training – will the installation 
require human intervention? 
» Supporting measures – is the 
installation able to work on its own, 
or is it most effective if combined 
with other measures? 
For the purpose of this assessment, three 
different scales of climate change adaptation 
strategies are considered. Listed under each, 
are critical public infrastructure that will 
be the focus of adaptation measures in this 
assessment: 
Site-specific installations that protect a 
single property or asset (Chapter 8 ): 
• Pump Stations 
• Beach Fire Station 
• DPW Building 
Shoreline/area-wide strategies that could 
protect multiple properties (Chapter 9 ): 
• Main Street, near the Belle Isle Bridge 
• Pleasant Street, at Ingleside Park 
• Washington Avenue, at Lewis Lake 
• Shirley Street, on Point Shirley 
Policy- or regulation-based measures to 
provide town-wide protection standards 
(Chapter 10 ): 
• New construction 
• Redevelopment projects

7-3 STRATEGIZE: Living with Coastal Waters 
The strategies in this assessment focus on 
Town-owned facilities, or within public right- 
of-way, to provide the Town with installations 
that are within their own control and can be 
implemented in the near term. This focus does 
not discount the importance of understanding 
how other public service providers are 
modifying their facilities to coastal flooding. 
As part of the assessment process, the project 
team met with the Massachusetts Department 
of Conservation and Recreation (DCR) to 
present the findings of the Boston Harbor 
Flood Risk Model (BH-FRM) and discuss 
resilience initiatives the agency is working on 
or have considered. 
This report should open the door for other 
follow-up discussions about community-level 
resilience planning and future implementation 
phasing. Meetings with other service providers 
in town could include: 
• Massachusetts Water Resources 
Authority (MWRA) 
• Massachusetts Port Authority 
(Massport) 
• Massachusetts Department of 
Transportation (MassDOT) 
• Eversource 
Winthrop Beach

7-4 STRATEGIZE: Living with Coastal Waters 
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8-1 STRATEGIZE: Site-Specific Adaptation Measures 
8 As identified on the critical infrastructure 
mapping ( Figure 6-1 ), there are several 
important utility facilities scattered throughout 
the community. This section looks specifically 
at site and building retrofits for public utilities 
and structures. However, these adaptation 
measures may also be applied to other asset 
types, private residences and commercial 
buildings. 
Overview of Site Adaptation 
Types 
Sometimes, moving critical resources out of 
the flood zone is the most feasible option for 
resilience. While it may seem obvious to either 
relocate or raise structures and equipment for 
flood protection, each infrastructure type and 
location requires consideration of the potential 
benefits and drawbacks. 
Relocating structures or equipment would 
offer the most protection to infrastructure 
within an area subject to flooding. It seems 
to make the most sense to avoid the threat of 
flooding by moving away from it. However, 
with pump stations, pressure valves, and 
substations, associated utility lines and 
building connections may not be a feasible 
option. If relocation is physically feasible, 
steps for implementation include securing a 
new property and funding, and identifying 
challenges of construction or movement of the 
infrastructure. 
STRATEGIZE: Site-Specific 
Adaptation Measures 
Elevating critical infrastructure above 
projected flood depths can also protect assets 
from flood damage. This may include raising 
entire buildings, certain utilities, or equipment. 
Elevating these assets will require adequately 
designed foundations that will exceed potential 
flood water depths and manage flood water 
velocities, wind, and earthquake loads. 
Oftentimes critical infrastructure cannot 
be moved or raised, and other adaptation 
measures must be explored. 
Wet floodproofing can allow an asset to 
withstand flooding, and recover more quickly 
after the water has receded. Types of wet 
floodproofing include building with flood 
resistant materials, anchoring equipment (for 
Elevated building. Source: StormSmart Coasts

8-2 STRATEGIZE: Site-Specific Adaptation Measures 
instance, fuel tanks), and installing quick 
disconnects for appliances that may short out 
or be filled with contaminated water during 
a flood. Flood vents and pumps can prevent 
walls from collapsing due to high water levels 
or water saturated soils. However, pumps must 
be timed appropriately, to match the exterior 
flood levels as they recede. 
Dry floodproofing strategies rely on exterior 
building walls to act as a flood barrier. To 
help create a watertight building, sealants or 
impermeable layers can be applied to walls 
and floors. Flood shields and watertight 
access hatches can also contribute to building 
protection. Flood shields are temporary 
installations to barricade doors and windows. 
Inside the buildings, backflow valves can 
prevent contaminated water from entering a 
building through sewer or drain pipes. And, as 
a backup measure, pumps are recommended 
to remove water that may still penetrate dry 
floodproofing measures 
Perimeter Barriers can be permanent 
or temporary vertical structures aimed at 
preventing flood waters from reaching a 
particular asset. Permanent barriers include 
sea walls or bulkheads. Temporary barriers 
are stored locally and installed prior to a 
flood event. Semi-permanent barriers are a 
combination of these, often a knee wall is 
built to a certain height with an option to add 
temporary structures to adapt to higher flood 
elevations. Alternatives to hard structures 
include berms or levees. These are earthen 
mounds, sometimes with a structural base, 
designed to block flood waters from entering 
certain areas. 
Although they can be quite effective, barriers 
only offer protection to a specific height, 
so overtopping is still possible. Another 
consideration, for temporary installations, is 
Flood Shield 
Source: Flood Control International 
Example of dry floodproofing 
Source: Flood C.I. 
that the wall components may require storage 
space, personnel training for installation, and 
enough warning time to install the structure. 
SCADA (Supervisory Control and Data 
Acquisition) systems allow facilities to be 
controlled from remote locations. Technologies 
such as this can help raise awareness of 
flood risk to assets and issue warnings that 
may reduce damages or prevent failure of 
components.

8-3 STRATEGIZE: Site-Specific Adaptation Measures 
Key to Estimated Range of Costs: 
$ < $100,000 
$$ $100,000 to $500,000 
$$$ $500,000 to $3,000,000 
$$$$ $3,000,000 to $10,000,000 
$$$$$ > $10,000,000 
Revere Street Pressure Reducing Valve 
Station 
Table 8-1 Range of costs for site 
adaptations 
RECOMMENDED ADAPTATION 
CONCEPT COST* 
Relocate $ - $$$$$ 
Elevate $ - $$$$ 
Wet- or Dry Floodproofing $ - $$$ 
Perimeter Barriers $ - $$$$$ 
Communication Improvements 
(e.g. SCADA) $ - $$$ 
* estimates are initial capital costs, and do not include annual 
expenses required to maintain the measure over the design life. 
It is assumed that the measures will be installed on publicly- 
owned property. Table adapted from Amtrak NEC Climate 
Change Adaptation Plan- Phase III Pilot Study , March 2017

8-4 STRATEGIZE: Site-Specific Adaptation Measures 
Potential Strategies for Sewer 
Pumping and Pressure Re - 
ducing Valve (PRV) Stations 
Three major sewer and wastewater pumping 
stations in town are identified within BH-FRM 
flood areas – Pico Avenue, Revere Street, and 
Pleasant Court. These stations collect and 
distribute hundreds of thousands of gallons 
of sewerage each day. The stations are at 
specific low points in the community to collect 
neighborhood waste and pump it out to the 
larger sewer mains. 
The station at Revere Street is also home to 
a Pressure Reducing Valve Station (PRV), 
which is where the Department of Public 
Works (DPW) controls potable water flow into 
Winthrop. 
Table 8-2 Potential Sewer Pump Station Flood Depths and Adaptation Installations 
WATER/ 
WASTEWATER 
STATION 
POTENTIAL DEPTH OF 
FLOODING (IN FEET; 1% 
CHANCE WATER LEVEL) 
POTENTIAL WALL HEIGHT 
(FLOOD WATER LEVEL 
PLUS 1-FT FREEBOARD) 
POTENTIAL WALL PERIMETER 
PRESENT 
DAY 2030 2070 PRESENT 
DAY 2030 2070 
SURROUND 
EXISTING 
BUILDING 
REPLACE 
EXISTING 
FENCE 
Pleasant 
Court 0’-9” 2’-0” 4’-9” 1’-9” 3’-0” 5’-9” 150’ 200’ 
Pico Avenue 0’-9” 1’-6” 4’-4” 1’-9” 2’-6” 5’-4” 120’ 175’ 
Revere St 
Sewer Pump 
Sta 
Dry Dry 2’-3” - - 3’-3” 120’ 
275’ 
(surrounding 
both 
buildings) Revere St PRV Dry Dry 2’-3” - - 3’-3” 140’ 
Table 8-2 presents the modeled flood depths 
that may occur during a 1% chance water 
surface elevation (one chance in 100, or 100- 
year water level). These stations were recently 
updated with raised first floors, water resistant 
floor panels, and generator upgrades. 
Dry floodproofing techniques could be applied, 
including the installation of flood doors on 
the stations. Potential walls could be built to 
at least the 2030 flood depth with 1-foot of 
freeboard. Walls should be designed to be 
able to adapt, in height, to future conditions in 
response to climate change and sea levels rise. 
Implementation, including cost estimates and 
potential permitting requirements, is explored 
in Chapter 11 .

9-1 STRATEGIZE: Shoreline Adaptation Measures 
Area-wide strategies should be considered for 
long, linear infrastructure, or when several 
assets are grouped within one focus area. 
Strategies focused at the shoreline and within 
the community can make these locations more 
resilient to coastal flooding. 
These strategies will require significantly 
more time and effort to finance, design, 
permit, and construct than the site-specific 
installations presented above. However, they 
are also typically more cost effective by 
providing protection for multiple public and 
private assets. The strategies may range from 
a couple of hundred linear feet shoreline, to 
a couple thousand linear feet, and involve a 
combination of public and private properties. 
9 STRATEGIZE: Shoreline 
Adaptation Measures 
“Every storm makes changes; 
and every change has its 
consequences. Undoubtedly 
we can keep the present area 
of Winthrop, and perhaps even 
persuade the ocean to enlarge 
it rather than wear the shore 
line away. However, it must be 
remembered that this will only 
be so if constant vigilance is 
maintained and the walls and 
breakwaters kept in repair.” 
William H. Clark, The History of Winthrop 
1952 
Yirrell Beach

9-2 STRATEGIZE: Shoreline Adaptation Measures 
To make installations like this possible, it 
is crucial to open communication between 
the Town, property owners, community, and 
regulatory agencies early in the planning 
process to gain support, develop partnerships, 
secure funding, and set realistic project 
timelines. 
Where feasible, natural systems and processes 
should be employed to help protect the 
Town from coastal flooding and provide 
ecological benefits. The potential for “green 
infrastructure” installations exist where large 
areas of natural resources (e.g. beach, tidal 
flats, or salt marsh) line the shore. However, in 
many locations in Winthrop, the constructed 
environment may limit this type of installation, 
and engineered barriers are more likely to 
be utilized. Here, more traditional “gray 
infrastructure” is appropriate. 
Green Infrastructure 
Existing and constructed green infrastructure 
has proven ecological benefits for coastal 
communities. Green infrastructure includes, 
but is not limited to, salt marsh and dune 
restoration, and living shorelines. A living 
shoreline may involve planting salt marsh 
and fringe marsh behind a biodegradable 
coir or rock sill, and creating tidal channels 
to enhance restoration and drainage. The 
ecological benefits include: 
• Absorption of wave energy. 
• Erosion protection. 
• Water quality improvement. 
• Habitat for wildlife and plant species. 
• Visual character enhancement along the 
shoreline. 
In addition, some of these systems maintain 
themselves after storms and flood events, and 
adapt to changes in sea level rise (NOAA, 
2015). 
Living Shoreline after construction 
Living shoreline after vegetation growth 
NOAA’s Coxsackie State Boat Launch Living 
Shoreline Project (Source: noaa.gov )

9-3 STRATEGIZE: Shoreline Adaptation Measures 
Careful study of the proposed green 
infrastructure location, and plans from 
experienced designers will help avoid adverse 
impacts to existing habitat and wildlife. 
Other considerations include project cost and 
maintenance requirements, as storm events can 
alter infrastructure and reduce its effectiveness. 
Gray Infrastructure 
Humans have always been attracted to 
water, and the shoreline of Winthrop is no 
exception. The Town is completely built out 
(MAPC, 2014), with buildings and pavement 
abutting beaches and other wetlands. Gray 
infrastructure, or hard engineered structures 
(e.g. sea walls, stone revetment, drainage pipes 
and outfalls, etc.) have made this build out 
possible. 
However, these hard structures, to various 
degrees, may reflect wave energy. This can 
cause erosion to adjacent properties or fronting 
coastal resources (e.g. beaches, dunes, etc.). 
Over time, the structures themselves may be 
undermined by the erosion of the beach in 
front of it, causing eventual collapse and costly 
repair. In addition, beach erosion over time can 
limit areas for recreation, wildlife habitat, and 
ability of this natural resource to provide wave 
attenuation. 
One benefit to constructing these steel and/ 
or concrete structures is that they can be 
vertically extended over time. This would 
allow wall height to be increased in phases as 
data regarding future impacts from sea level 
rise and storm surges is refined. 
In some situations, a concrete cap or wall 
may benefit from aesthetic details, to soften 
the visual impact. Concrete form liners can 
be designed with patterns to create an artistic 
statement and/or announce a particular place or 
neighborhood. Another way to break up a large 
wall could be to integrate elements such as art, 
planters, or terracing. 
Pico Beach Seawall (gray infrastructure

9-4 STRATEGIZE: Shoreline Adaptation Measures 
Hybrid installation example 
Hybrid Installations 
Some locations may benefit from a hybrid 
of green and gray infrastructure to provide 
protection for a wider range of potential 
flood depths. Coastal wetland plantings and 
berms can be designed to manage low to 
medium tidal flooding, where engineered 
walls could be provided for additional 
storm surge protection (NOAA, 2015). 
In any case, shoreline installations can 
be designed, not only to create barriers 
to coastal flooding, but also provide an 
opportunity to benefit the surrounding 
community. These benefits may include 
improved public access to the waterfront 
and/or enriching an area’s visual character. 
Conceptual Design 
Of the eight flood areas identified in Chapter 
5 , the Project Management Team (PMT) 
identified four locations for further study. 
The following criteria was used to select the 
locations: 
• Includes the highest ranked critical 
infrastructure identified in Chapter 6 
• Can use public property to install the 
adaptation 
• Locations will illustrate different types 
or combinations of adaptation measures 
Due to these criteria, potential installations 
described in this chapter include: 
Belle Isle Marsh Flood Area – planted 
berm with sidewalk along Morton Street 
right-of-way 
Ingleside Park Flood Area – hybrid sea 
wall, with seating and planting adjacent to 
Donovan’s Beach 
Lewis Lake Flood Area – flood barrier at 
Washington Avenue 
Point Shirley Flood Area – beach 
nourishment/dune creation at Yirrell Beach

9-5 STRATEGIZE: Shoreline Adaptation Measures 
The following sections discuss the probable 
flood entry points at each location, and a 
near-term adaptation that is intended to 
withstand a 1% chance water level in the 
modeled 2030 conditions. Future adaptations 
will require more focused location studies 
and conversations with property owners, 
neighborhoods, local boards, state agencies, 
and other interested parties. The materials on 
the following pages have been structured to 
allow each flood area section to be extracted 
from the assessment in support of future 
implementation phases. The sections can serve 
as an education packet for working group 
meetings, support communication efforts with 
public and private partners, and be included in 
future funding applications. Implementation, 
including estimated cost and potential 
permitting, is explored in Chapter - . 
As outlined throughout this report, the scope 
of this study is to address only the effects 
of coastal flooding and sea level rise to the 
town. The following concept designs are 
not intended to reduce the effects of inland 
precipitation and storm drainage patterns. It is 
recommended that further study be conducted 
to address inland flooding in concert with the 
information in this report. Potential outcomes 
could include: 
• Identification of flood areas and depths 
inclusive of all coastal and inland 
flooding 
• Selection of locations and design types 
for stormwater upgrades, including 
pipe upsizing and green infrastructure 
(plants and infiltration systems to help 
“ Soak Up the Rain ” see EPA website 
for more information ) 
• Restoration of streams and wetlands 
• Conceptual design for additional 
adaptation measures 
Belle Isle Marsh from Morton Street

9-6 STRATEGIZE: Shoreline Adaptation Measures 
Figure 9-1 Map of Adaptation Locations 
Winthrop Massachusets 
Lewis
Lake 
Snake
Island 
Coughlin
Park
Deer Island 
Boston Logan
International Airport 
Deer Island
Wastewater
Treatment Plant 
N 
SHORT BEACH
CREEK
BELLE ISLE
MARSH
BOSTON
HARBOR
BOSTON
HARBOR
BOSTON
HARBOR
BELLE ISLE
INLET
BROAD SOUND
BROAD SOUND 
The Five Sisters 
Winthrop
Head
Winthrop
Beach
Donovan’s
Beach 
Crystal
Cove 
Town
Landing 
Pico Playground
& Beach 
Town
Hall 
Winthrop
High School 
Small Park
Small Beach
Fort Banks
Playground
Yirrell
Beach
Little
League
Field Miller
Field
Winthrop
Golf Club
Veterans
Field 
Central Business
District 
The Basin 
Winthrop
Cemetery 
Washington Ave
Winthrop St
Winthrop St
Main St
Pleasant St
Shirley St
Shirley St
Veterans Road
Winthrop Shore Dr
Revere St
Morton Street 
REVERE ST PUMP 
STATION 
PLEASANT COURT 
PUMP STATION 
PICO AVE PUMP 
STATION 
NAHANT AVENUE 
FLOOD AREA 
(7.5 AC) 
LEWIS LAKE 
FLOOD AREA 
(153 AC) 
BELLE ISLE MARSH 
FLOOD AREA 
(106 AC) 
INGLESIDE PARK 
FLOOD AREA 
(38 AC) 
WINTHROP BEACH 
FLOOD AREA 
(88 AC) 
POINT SHIRLEY 
FLOOD AREA 
(88 AC) 
Shoreline Adaptation 
Site Specific Adaptation 
FISHERMEN'S BEND 
FLOOD AREA 
(35 AC)

9-7 STRATEGIZE: Shoreline Adaptation Measures 
The Belle Isle Inlet once flowed freely over the 
tidal flats that were filled to construct Logan 
Airport in the 1920s ( Massport website ). 
Today, this opening between Winthrop and 
East Boston is just under 200-feet wide, 
traversed by the Belle Isle Bridge. The 
bridge is the primary evacuation route for 
the Winthrop community and Deer Island 
Wastewater Treatment Plant employees. It was 
recently reconstructed with the low member of 
the structure about one- to two-feet above the 
BH-FRM mapped 1% chance water level. In 
2030, the bridge is projected to be only six- 
inches above the 1% chance water level. 
Ultimately, raising the bridge and approach 
roadways should be explored. However, the 
design process to construct the 2013 bridge 
faced firm height restrictions from the Federal 
Aviation Administration (FAA). Because 
the FAA is unlikely to change the bridge 
height restriction in the near term, further 
study of potential scour and debris impacts 
is suggested. The bridge evaluation may also 
consider bridge components, connections, and 
lifecycle for replacement or elevation. Bridge 
adaptations may include additional riprap 
to help protect foundations against swiftly 
moving flood waters, and defend against debris 
impacts. Structural upgrades can also increase 
resistance to flood waters and floating debris. 
Although the bridge is not estimated to be 
overtopped by flood waters, the approaches 
to the bridge are. During a 1% chance water 
surface elevation in 2030, Main Street could 
experience as much as 6” of flooding, making 
it impassible. Although not part of this study, 
Saratoga Street, on the East Boston side of 
the bridge, is also at risk of flooding. On the 
Winthrop side of the bridge, there are two 
flood pathways identified by the BH-FRM: one 
along Morton Street, and another on private 
property at the west end of Morton Street 
( Figure 9-4 ). 
BELLE ISLE MARSH FLOOD AREA

9-8 STRATEGIZE: Shoreline Adaptation Measures 
Public Infrastructure Adaptation 
Recommendations 
To help keep the water off Main Street in 2030, 
the assessment team studied the feasibility of a 
hybrid infrastructure installation along Morton 
Street (from Pleasant Street to Fairview Street; 
Figure 9-4 ). In addition to being identified as 
a flood pathway, the roadway right-of-way is 
within the Town’s control. As such, the right- 
of-way was determined, by the PMT, to be 
a good location to start looking at resilience 
options. A planted berm was identified for 
study along Morton Street to discourage flood 
water from entering the area. The berm could 
include a walking path to tie in with existing 
plans for the Town’s Belle Isle Marsh Marine 
Ecology Park and Marsh Walk . 
Plans for the new park are currently designed 
to connect Pleasant Street to a new passive 
recreation park on Morton Street. From the 
new park, the trail will connect with existing 
walking trails to the north of Belle Isle 
Cemetery. 
A planted berm along Morton Street was 
modeled by the Woods Hole Group, using the 
BH-FRM, to identify whether it could reduce 
the identified flood depth along Main Street. 
Flood modeling of the installed berm did prove 
to be effective for some of the adjacent Morton 
Street neighborhood, but ineffective for 
reducing flooding on Main Street. This shows 
that both flood pathways must be addressed for 
the adaptation to be effective. 
Inundation Depth 
Figure 9-2 Belle Isle Marsh Coastal Flood Modeling for Projected 2030 1% Chance Storm 
Shoreline Adaptation

9-9 STRATEGIZE: Shoreline Adaptation Measures 
If Main Street is to remain passable during 
future coastal flood events, there must be 
discussions with private property owners along 
the shoreline, between the bridge and Morton 
Street. Suggestions could be made to repair/ 
modify existing shoreline structures, install 
new structures, or create living shorelines. 
If agreements with private owners are not 
possible in these locations, additional measures 
must be considered landward of the flood 
pathways to protect Main Street and the pump 
station. 
Supporting measures, considering inland 
flooding will also need to be addressed. 
Existing drainage pipes could be enlarged 
to hold more water during a storm event. 
Check valves should be installed at existing 
outfalls to prevent coastal water from entering 
the stormwater system. Additionally, green 
infrastructure installations along Morton 
Street, and streets perpendicular to it, may 
promote stormwater infiltration to reduce flood 
depths. 
Natural Resource 
Recommendations 
Due to sea-level rise, the marsh along the 
northeastern shores of Winthrop will want to 
expand inland over the next several decades 
( Appendix F ). No immediate adaptations are 
required to maintain the natural resources 
in this area. However, in the long-term, and 
during storm events, more frequent overbank 
flooding can be expected to surrounding 
properties and the fringe marsh areas may 
be expected to expand. Smaller, proactive 
restoration measures could be considered 
along the shorelines to protect infrastructure 
and provide natural resource expansion and 
protection. Potential options could consider 
living shoreline applications and targeted thin 
layer deposition projects that would involve 
the placement of clean, compatible sediment in 
thin layers on the existing salt marsh to assist 
the elevations in keeping up with the rising 
tidal increases. 
Figure 9-3 Potential Flood Levels at the Belle Isle Bridge

Winthrop
East
Boston 
BOSTON HARBOR
BELLE ISLE INLET
BELLE ISLE MARSH
SALT
MARSH
SALT
MARSH TIDAL
FLAT
TIDAL
FLAT
SALT MARSH
SALT MARSH
SHALLOW
MARSH
MEADOW
SALT
MARSH
BEACH 
MAIN ST
SUNSET ST
GIRDLESTONE RD
TILESTON RD
SARATOGA ST
MORTON ST
PLEASANT CT
Mobil
Ace
Hardware
Pleasant
Park
Yacht
Atlantis
Marina
Belle Isle Seafood
Boat Yard
WILLIS AVE
PLEASANT ST PLEASANT ST
MARSHALL ST
BEAL ST
JERALD ST
PLEASANT PARK RD
AMELIA AVE
FAIRVIEW ST
READ ST
N
200’ 400’ 0 
A
A 1 
Pleasant Court
Pump Station 
Dunkin
Donuts 
Figure 9-4 Morton Street Concept Plan 
F l o o d A r e a : B e l l e I s l e M a r s h 
2070 PROBABLE FLOOD ELEVATION 
2030 PROBABLE FLOOD ELEVATION 
PRESENT DAY PROBABLE 
FLOOD ELEVATION 
POTENTIAL WALL TO ALLOW 
FOR VERTICAL EXTENSION IN 
FUTURE CONDITIONS 
BELLE ISLE MARSH 
POTENTIAL PLANTED 
BERM 
OPPORTUNITY 
FOR ADDITIONAL 
ADAPTATION 
MEASURES 
POTENTIAL 
PLANTED 
BERM 
2030 FLOOD LIMIT 
BELLE ISLE 
BRIDGE 
EXISTING GRADE 
Figure 9-5 Section A-A 1 (Morton Street) 
NOT TO SCALE 
EXISTING STORMWATER 
OUTFALL 
FLOOD PATHWAY 
FLOOD PATHWAY 
FLOOD PATHWAY

READ ST
WALDEN ST
EDWARD ST 
2030 FLOOD AREA SIZE Approximately 106 acres (10% of Winthrop) 
CRITICAL 
INFRASTRUCTURE 
WITHIN FLOOD AREA 
Main Street (evacuation and Deer Island trucking route) 
2030 1% CHANCE 
STORM FLOOD DEPTH 2'-3” (at Morton Street) 
REVIEWED 
ADAPTATION 
A planted berm along Morton Street may reduce the identified flood path, 
and reduce the flood depth along Main Street. 
MODELED 
EFFECTIVENESS 
Relatively ineffective. The berm protects a few homes, but generally the flood 
water will still enter the area west of the Morton Street installation. 
ADAPTATION 
LIMITATIONS 
The berm cannot protect Main Street on its own. 
Barriers offer protection to only a certain elevation, so overtopping is possible. 
POTENTIAL 
SUPPORTING 
MEASURES 
Upsize stormwater pipes, installing flapper valves on all outfalls. 
Discuss potential adaptations with private property owners between the Belle 
Isle Bridge and Morton Street (e.g. repair/modify existing shoreline structures 
and/or install green infrastructure). 
MORTON STREET 
Figure 9-6 Potential Morton Street Flood Levels

9-12 STRATEGIZE: Shoreline Adaptation Measures 
View toward Boston from Donovan's Beach 
Southbound view along Pleasant Street 
(Donovan's Beach on right) 
As discussed in Chapter 5 , Ingleside Park was 
swamp land until it was filled in 1936 (Clark, 
1952). The flood pathway to Ingleside Park is 
at Donovan’s Beach, assumed to be the same 
location where a tidal stream once entered the 
swamp. Coastal flooding on Pleasant Street 
could be 8-inches deep by 2030, making this 
roadway impassible during a major storm 
( Figure 9-9 ). 
INGLESIDE PARK FLOOD AREA 
Public Infrastructure Adaptation 
Recommendations 
The modeled 1% chance water surface 
elevation in 2030 shows water overtopping 
the existing 3-foot high seawall at Donovan’s 
Beach. Shoreline improvements could include 
a hybrid wall, as shown on Figure 9-10 , to

9-13 STRATEGIZE: Shoreline Adaptation Measures 
Inundation Depth 
Figure 9-7 Ingleside Park Coastal Flood Modeling for Projected 2030 1% Chance Storm 
increase the height of the barrier, infiltrate 
stormwater, and provide erosion control at 
the beach, habitat for wildlife, and seating to 
beach users. 
From the results of the BH-FRM, the PMT 
considered a 1.5-foot high wall installation 
all along the Donovan’s Beach property line. 
WHG modeling of this installation shows it to 
be an effective adaptation measure to prevent 
storm surge from entering a large area under 
2030 conditions. 
However, Ingleside Park does drain a 
considerable amount of stormwater from 
development on the west side of Winthrop. 
To effectively adapt to future climate change 
conditions, other supporting measures must 
be studied to consider stormwater runoff 
and increased ground water levels due to 
sea-level rise. These measures may include 
enlarging drainage pipes to hold more water 
during a storm event, installing flapper valves 
to prevent coastal water from entering the 
stormwater system, and installing green 
infrastructure along roadways and in open 
spaces to promote stormwater infiltration 
and reduce flood depths. Depending on 
future effects of sea-level rise and increased 
precipitation at the park, the feasibility of 
restoring the 19 th century stream may also be 
considered. 
Natural Resource 
Recommendations 
Office of Geographic Information (MassGIS) 
wetlands data, mapped by the Massachusetts 
Department of Environmental Protection 
(DEP), identifies a strip of salt marsh 
extending from just south of the Loring Road 
Boat Ramp to just north of Donovan’s Beach. 
Although living shorelines are beneficial in 
some coastal areas, it is not recommended 
here. Construction along the beach could cause 
sediments to adversely impact the existing salt 
marsh system. The proposed hybrid wall will 
still provide some level of ecological benefits, 
as well as other public amenities. 
Shoreline Adaptation

A A 1 
ATS
SALT MARSH 
Court
Park 
Donovan
Beach 
PLEASANT ST
PLEASANT ST
CIRCUIT RD
BIRCH RD
OURT RD
EMERSON RD
LOWELL RD
EDGEHILL RD
INGLESIDE AVE
ENFIELD RD
LINCOLN ST
BROOKFIELD RD
PALMYRA RD
WHEELOCK ST
INGLESIDE
PARK
Former Middle
School
Larson R
200’ 400’
N
0 
AREA 
Figure 9-8 Pleasant Street Concept Plan 
2030 FLOOD AREA SIZE Approximately 38 acres (4% of Winthrop) 
CRITICAL INFRASTRUCTURE 
WITHIN FLOOD AREA Pleasant Street (Evacuation Route) 
2030 1% CHANCE STORM 
FLOOD DEPTH 8” 
REVIEWED ADAPTATION 
Replacement of existing seawall with taller, adaptable flood barrier and 
planted seat walls. The green infrastructure on the beach-side of the barrier 
will provide ecological and recreational community benefits. 
MODELED EFFECTIVENESS Effective as a coastal flood adaptation 
ADAPTATION LIMITATIONS 
Ingleside Park drains nearly 100 acres in town & this adaptation does not 
consider inland precipitation. 
Flood barriers offer protection to only a certain elevation, so over-topping is 
possible. 
POTENTIAL SUPPORTING 
MEASURES 
Upsize stormwater pipes, installcheck valves at all outfalls 
Repair and/or modification of adjacent existing shoreline structures 
Install green infrastructure in town to promote stormwater infiltration & 
reduce runoff 
Stream restoration feasibility study 
F l o o d A r e a : I n g l e s i d e P a r k 
BOSTON 
HARBOR 
POTENTIAL BARRIER / 
GREEN INFRASTRUCTURE 
INSTALLATION 
2030 FLOOD LIMIT 
2030 FLOOD LIMIT 
EXISTING 
STORMWATER 
OUTFALL 
EXISTING 
SALT 
MARSH 
FLOOD PATHWAYS 
OPPORTUNITY 
FOR ADDITIONAL 
ADAPTATION 
MEASURES 
Figure 9-9 Potential Pleasant Street Fl 
2070 P 
2030 P 
Figur 
NOT T

ood Levels 
FORMER WETLAND SYSTEM AT INGLESIDE PARK. 
1817 MAP OF BOSTON HARBOR, SURVEYED BY 
ALEXANDER WADSWORTH 
WATER-SIDE STEPS/PLANTINGS AT CALGARY 
RIVERWALK, CANADA 
PROBABLE FLOOD ELEVATION 
PROBABLE FLOOD ELEVATION 
POTENTIAL ADAPTABLE WALL 
EXISTING BEACH 
PLEASANT STREET 
EXISTING BEACH EXISTING 
CONCRETE WALL 
EXISTING SIDEWALK 
AND SEATING AREA 
POTENTIAL GREEN 
INFRASTRUCTURE INSTALLATION 
re 9-10 Section A-A 1 (Pleasant Street ) 
O SCALE 
INGLESIDE PARK 
FISHERMEN'S 
BEND 
LEWIS LAKE

9-16 STRATEGIZE: Shoreline Adaptation Measures 
LEWIS LAKE FLOOD AREA 
Where it was once open to the harbor, Lewis 
Lake is now landlocked with a single outfall 
and a tide gate to regulate its holding capacity. 
Prior to the turn of the 20th century, Lewis 
Lake was an extensive wetland system, 
including Fishers Creek, a tidal stream. 
When Winthrop began to grow as a vacation 
destination, a steam train line was constructed 
to deliver tourists from Boston to the town 
center and Winthrop Beach. A railroad bridge 
was built over the wetlands and, several 
years later, another bridge was constructed 
connecting Washington Avenue to Shirley 
Street. Soon after, the Washington Avenue 
bridge connection was filled to create a 
roadway and adjacent parcels. Though the rail 
line was eventually demolished, part of the 
railroad bridge bed, near Washington Avenue, 
remains.

9-17 STRATEGIZE: Shoreline Adaptation Measures 
Today, Lewis Lake collects stormwater 
drainage from approximately half of the town. 
The water table is high, and the identified area 
of coastal flooding also experiences flooding 
from extended amounts of precipitation. 
During the 1% chance flood in 2030, 
Washington Avenue could be under eight 
inches of coastal flood water ( Figure 9-14 ). 
Public Infrastructure Adaptation 
Recommendations 
The path of coastal flooding in the Lewis Lake 
flood area comes from Crystal Cove ( Figure 
9-12 ). This armored shoreline is privately 
owned. Therefore, the PMT considered a flood 
barrier along the Washington Street right- 
of-way in front of these properties. Because 
of this, careful planning would be required 
to keep open access to the Elks Club and 
residential properties of flood emergencies. 
The barrier would be installed at the back of 
the sidewalk, and could be designed to extend 
vertically, adapting to future conditions. 
Consideration of staff availability to respond 
to flood warnings and receive appropriate 
training is important to the success of this type 
of installation. 
When the Lewis Lake flood area is modeled 
with this adaptation installation in place, it is 
fairly effective at obstructing the coastal flood 
water. This assumes that the culvert and tide 
gate system at the south side of Washington 
Avenue work as intended. However, it is still 
likely that there will be significant flooding 
at Lewis Lake, due to precipitation during 
a storm event. Poor drainage will lead to 
flooding in this area even with the coastal 
adaptation in place. 
Discussions of access and protection is 
necessary with the property owners on the 
south side of Washington Avenue. Instead of 
installing a barrier along Washington Avenue, 
a combined effort to install the barrier and 
green infrastructure at the shoreline could also 
expand the protection area to include these 
private assets. Other long-term opportunities 
for exploration include raising Washington 
Avenue or reconstructing a bridge and 
restoring the creek. Creek restoration is further 
discussed in the below paragraphs. 
Inundation Depth 
Figure 9-11 Lewis Lake Coastal Flood Modeling for Projected 2030 1% Chance Storm 
Shoreline Adaptation

9-18 STRATEGIZE: Shoreline Adaptation Measures 
Natural Resource 
Recommendations 
Wetlands at Lewis Lake Park and the Winthrop 
Golf Course primarily include inland open 
water, regularly flooded marsh, and tidal fresh 
marsh resources. The SLAMM maps show 
minor changes by 2030 at the inland fringes 
of these marshes as salt laden water is able to 
further penetrate upstream in the system. Very 
small inland portions of the regularly flooded 
marsh areas begin to convert to tidal fresh 
marsh. By 2070, much of the park and golf 
course shows transition to open estuarine water 
and regularly flooded marsh, and expanded 
regularly flooded marsh, tidal flat and 
transitional scrub shrub areas into available 
upland areas. 
In the long-term, and during storm events, 
more frequent and expanded flooding can be 
expected throughout the Lewis Lake open 
space area, with additional inundation to 
adjacent developed areas due to storm surge. 
Long term choices regarding the future use 
of this open space will need to be considered. 
There is potential to restore the whole complex 
to its natural wetland state by reconnecting 
Lewis Lake to Boston Harbor and removing 
upstream impediments to flow and compliment 
with edge protection for the surrounding 
communities and infrastructure. This approach 
would restore the area to its historic condition 
of an ecologically beneficial salt marsh 
complex. 
Lewis Lake area in 1894 (aerial drawing by AF Poole) 
Wint HR op S H o R e 
d R ive 
S H i R ley St R eet 
l e W i S l ake 
REVERE 
Wa SH ington a venue

9-19 STRATEGIZE: Shoreline Adaptation Measures 
High water table at Winthrop Golf Club property 
Living shoreline solutions along the 
edges of developed areas would protect 
against future storm surge while also 
providing additional habitat resources. 
Restored wetland areas and living shoreline 
installations could also be integrated with 
elevated walkways, kayak/canoe launches, 
and hybrid infrastructure to enhance 
recreational opportunities and waterfront 
interaction throughout this area. As such, 
there is a unique opportunity to create 
a long-term vision of an expanded, but 
different, recreation resource in this area for 
the Town of Winthrop. However, protection 
of this area could also be considered 
through appropriate mitigation efforts at 
Washington Avenue and appropriate tide 
gate control. If the Town opts to try to 
maintain existing recreational uses, this area 
would need to continue to be fortified through 
adaptations along Washington Avenue. Even 
then, eventually fresh water drainage will 
be a significant problem for this area due to 
increased mean water elevations in Crystal 
Cove. As such, increased flooding over the 
mid- to long-term would be expected in this 
area.

F l o o d A r e a : L e w i s L a k e 
TIDAL FLATS 
WASHINGTON AVE AREA
160’ 320’
N
0 
LEWIS LAKE 
WASHINGTON AVE
VETERANS RD
RIVER RD
ELMWOOD AVE
SHIRLEY ST
OCEAN AVE
IRWIN ST
STU
BE 
CRYSTAL COVE 
ELKS CLUB
NORMAN F. DAW
PLAYGROUND
CR 
A
A 1 
Figure 9-12 Washington Avenue Concept Plan 
POTENTIAL ADAPTABLE 
FLOOD BARRIER, WITHIN 
RIGHT-OF- WAY 
2070 PROBABLE FLOOD ELEVATION 
EXISTING PARKING LOT AT ELKS LODGE 
2030 PROBABLE FLOOD ELEVATION 
PRESENT DAY PROBABLE FLOOD ELEVATION 
PRESENT DAY HIGH TIDE 
EXAMPLE FLOOD GATES (SOURCE: FLOODCONTROLINTERNATIONAL.COM) 
POTENTIAL BARRIER 
(WITHIN RIGHT-OF-WAY) 
2030 FLOOD LIMIT 
CRYSTAL COVE 
Figure 9-13 Section A-A 1 (Washington Avenue) 
NOT TO SCALE 
EXISTING 
STORMWATER 
OUTFALL 
OPPORTUNITY 
FOR ADDITIONAL 
ADAPTATION 
MEASURES 
2030 FLOOD LIMIT 
FLOOD GATE 
LOCATIONS 
FLOOD PATHWAY 
FLOOD PATHWAY 
FLOOD PATHWAY 
WAS 
AVE

RGIS ST
UNDERHILL ST
MOORE ST
EACON ST 
YSTAL
COVE 
CAMERA LOCATION ELEVATION: 8.5’
GROUND PLANE 
FLOOD PRESENT (3”) 
FLOOD 2030 (1’6”) FLOOD 2070 (4’3”) 
Figure 9-14 Potential Washington Avenue Flood Levels 
HINGTON 
NUE 
2030 FLOOD AREA SIZE Approximately 153 Acres (15% of Winthrop) 
CRITICAL 
INFRASTRUCTURE 
WITHIN FLOOD AREA 
Washington Avenue evacuation route, Winthrop High School 
2030 1% CHANCE 
STORM FLOOD DEPTH 1'-6” 
REVIEWED ADAPTATION 
Vertical barrier within the Washington Avenue right-of-way, with an option 
working with private property owners to construct the barrier along Crystal 
Cove. 
MODELED 
EFFECTIVENESS Barrier is fairly effective at obstructing coastal flood water. 
ADAPTATION 
LIMITATIONS 
Adaptation effectiveness assumes that the culvert and tide gate system at 
the south side of Washington Avenue work as intended. 
Flood Barriers offer protection to only a certain elevation, so overtopping is 
possible. 
Flood gates require personnel and adequate response time. 
Significant flooding is still anticipated at Lewis Lake, due to precipitation during 
a storm event. Poor drainage will lead to flooding in this area even with the 
coastal adaptation in place. 
POTENTIAL SUPPORTING 
MEASURES 
Upsize stormwater pipes, install check valves at all outfalls 
Repair/modify existing shoreline structures

9-22 STRATEGIZE: Shoreline Adaptation Measures 
POINT SHIRLEY FLOOD AREA 
First settled in the 1600s, Point Shirley has a 
long history of flooding and storm damage. 
(MHC, 1981). The shore has shifted, filled, and 
receded over time from both natural sediment 
movement and development restrictions. 
Public Infrastructure Adapta - 
tion Recommendations 
Because there are multiple coastal factors 
affecting the Point Shirley and Shirley Street 
neighborhoods, maintaining the present 
conditions of these areas cannot be expected 
to endure with climate change. A muti-faceted 
approach will be required over time to adapt to 
increased coastal storms and sea level rise. 
Recent projects that the Town has constructed 
or proposed include: 
• Drainage upgrades along Tafts Avenue, 
including enlarged pipelines to hold 
more stormwater during coastal flood 
events and duckbill valves to block 
water entering the stormwater system 
from Boston Harbor. 
• Annual Sand dune creation 
• Shoreline enhancement at Coughlin 
Park 
The PMT identified Yirrell Beach as the most 
likely location for a Town-installed adaptation 
measure. Beach nourishment/dune creation 
was modeled to see whether this type of 
adaptation could make Shirley Street more 
resilient to climate change. The Point Shirley 
flood area will still get overtopped with the 
adaptations in place but the overtopping is 
much less significant, and may be reduced 
drastically for the full range of storms. The 
dune and beach nourishment also shows 
reduction of probability and depth levels in 
the area. A beach and dune system needs to be 
properly engineered where, being designed and

9-23 STRATEGIZE: Shoreline Adaptation Measures 
installed correctly, it could provide even more 
resiliency than indicated in this assessment. 
For example, the correct slope and width of the 
beach berm and dune elevation combination 
can make a big difference. 
Additional steps to help the Point Shirley flood 
area become more resilient to coastal flooding 
include: 
• Fund a study for beach nourishment 
and/or dune creation along Yirrell 
Beach. 
• Continue to update the drainage system 
with larger pipes and check valves at 
all outfalls. 
• Coordinate with property owners 
along the western shoreline of Point 
Shirley to create a consistent sea wall/ 
bulkhead. Today’s varying heights 
and gaps in the barrier make it easier 
for higher tides to infiltrate the 
neighborhood. 
• Coordinate with property owners 
within The Basin to consider salt marsh 
restoration from Coughlin Park to 
Winthrop Town Landing 
• Provide educational, floodproofing, 
and/or home raising programs 
Natural Resource 
Recommendations 
Irregularly flooded marsh and tidal flat 
resources currently exist along the Coughlin 
Park shoreline. By 2070, a large portion of the 
upland area of Coughlin Park could convert 
to beach and tidal flat without intervention. 
It is our understanding that there are ongoing 
projects to bolster the shoreline at Coughlin 
Park, which are not discussed in this document 
to avoid redundancy. 
Inundation Depth 
Figure 9-15 Point Shirley Coastal Flood Modeling for Projected 2030 1% Chance Storm 
Shoreline Adaptation

A
A 1 
BROAD SOUND 
BAY VIEW AVE
UNDINE AVE
SIREN ST
TRITON ST
BILLOWS ST
SHIRELY ST
PEBBLE AVE
HALE AVE
SHIRLEY ST
OTIS ST
TOWNSEND ST
MARYLAND AVE
TAFTS AVE
SHIRELY ST
SHIRELY ST
TERRACE AVE
HARBOR VIEW ROAD
GREEN HILL PATH
FAUNBAR AVE
WHITTIER ST
DEEPWATER ST
FOAM ST
GRAND VIEW
Coughlin
Park
Town
Landing 
THE BASIN
BOSTON HARBOR 
BREWSTER AVE
THE STRAND 
INT SHIRLEY AREA 
Cottage Hill
Point Shirley
DEER
ISLAND 
375’ 750’
N
0 
TIDAL
FLAT
AL
AT
TIDAL
FLAT 
F l o o d A r e a : P o i n t S h i r l e y 
Figure 9-16 Point Shirley Concept Plan 
SHIRLEY 
STREET 
POTENTIAL DUNE 
CREATION AT YIRRELL 
BEACH. OTHER ‘NATURAL’ 
OPTIONS, SUCH AS 
BEACH NOURISHMENT, 
SHOULD ALSO BE FURTHER 
INVESTIGATED 
EXISTING SALT 
MARSH 
EXISTING 
SALT 
MARSH 
PROPOSED LIVING 
SHORELINE FOR 
BANK STABILIZATION 
OPPORTUNITY TO EXTEND SALT 
MARSH AROUD THE BASIN 
CHECK VALVES MAY BE 
INSTALLED AT EXISTING 
STORMWATER OUTFALLS 
UNDERGROUND STORMWATER 
PIPES MAY BE ENLARGED TO 
ACCEPT MORE RUNOFF 
EXISTING SEA WALLS AND OTHER 
SHORELINE STRUCTURES MAY BE 
REPAIRED OR MODIFIED 
EXISTING PRIVATELY-OWNED 
SHORELINE STRUCTURE 
EXISTING 
STORMWATER 
OUTFALL 
EXISTING 
PUBLICLY-OWNED 
SHORELINE 
STRUCTURE 
EXISTING STORMWATER 
OUTFALL EXISTING PRIVATELY- 
OWNED SHORELINE 
STRUCTURE 
EXISTING PUBLICLY- 
OWNED SHORELINE 
STRUCTURE 
2030 FLOOD LIMIT 
NOT TO SCALE 
EXISTING SALT 
MARSH 
YIRRELL 
BEACH 
YIRRELL 
BEACH 
SHIRLEY STREET 
TAFTS AVENUE 
BAYVIEW AVENUE 
2030 FLO 
CRITICAL INFRA 
FLOO 
2030 1% CHAN 
D 
REVIEWED 
MODELED 
ADAPTATIO 
POTENTIA 
ME 
STORMWATER COLLE 
UPSIZED & TIDE GATE 
INSTALLED AT OUTFAL 
Figure 9-17 Sec 
TAFTS A

Potential Dune 
Potential Adaptation Strategies 
OD AREA SIZE Approximately 88 acres (9% of Winthrop) 
STRUCTURE WITHIN 
OD AREA Shirley Street/Tafts Avenue (Evacuation & Deer Island Trucking Route) 
CE STORM FLOOD 
EPTH 6” to 12” plus wave run-up and overtopping 
ADAPTATION Beach nourish-ment / dune crea-tion at Yirrell Beach (pending design study) 
EFFECTIVENESS Effective in reducing wave overtopping & flood depth levels if properly engineered. 
N LIMITATIONS 
No installation can be designed to eliminate wave run-up and overtopping. 
Natural installations (i.e. dune and salt marsh creation, beach nourishment) need space to grow over 
time. 
L SUPPORTING 
ASURES 
Coughlin Park shoreline stabilization project. 
Continue stormwater improvements to increase the capacity of pipes and install check valves 
were installed at the outfalls. 
Repair/modification of existing shoreline structures. 
Explore living shorelines at additional locations in the area. 
POTENTIAL SEA 
WALL EXTENSION 
POTENTIAL DUNE CREATION 
PROBABLE FLOOD ELEVATION 2070 
PROBABLE FLOOD ELEVATION 2030 
EXISTING BEACH EXISTING BEACH EXISTING 
SEA WALL 
CTION PIPES HAVE BEEN 
CHECK VALVES HAVE BEEN 
LS ALONG TAFTS AVENUE. 
BEACHGRASS PLANTED TO STABILIZE AN ERODED 
DUNE, SOURCE: MA CZM, STORMSMART PROPERTIES 
FACT SHEET 3 . 
LIVING SHORELINE INSTALLATION, BEAUFORT, NC, 
SOURCE: NOAA.GOV 
POTENTIAL WAVE HEIGHT 2030 
tion A-A 1 (Yirrell Beach) 
VENUE

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10-1 STRATEGIZE: Regulation and Policy 
10 STRATEGIZE: Regulation and 
Policy 
The coastal flooding and sea level rise, 
discussed throughout this report, will require 
collective actions across both public and 
private properties. When considering policy 
and regulatory changes, the Town will 
need to reach out to local groups, boards, 
commissions, and residents to educate them 
on the topics of coastal storms, local drainage 
systems, and predicted sea level rise. This 
can foster discussions on how the community 
might adapt to coastal flooding related to 
climate change. Discussions could address 
questions such as: 
What can the local government and individual 
property owners do to adapt to projected 
coastal flooding and other impacts of climate 
change? 
• What steps should be taken to further 
defend against rising flood waters? 
• How, and at what point, should the 
community consider a managed retreat 
from the shoreline? 
• Where should funds be directed first? 
What are the priorities? 
With community involvement, these questions 
can be addressed and decisions can be made 
on how Winthrop can look toward a resilient 
future. This may include the development of 
local regulations and policies overseen by the 
local government. 
Sunset view from Donovan's Beach, Source: Winthrop town website

10-2 STRATEGIZE: Regulation and Policy 
Municipal Regulations 
Winthrop’s current regulations can be 
adapted to prepare for projected water levels. 
Existing town ordinances should be reviewed 
and updated to increase the resiliency of 
Winthrop’s built environment. Regulatory 
modifications may be required to facilitate 
retrofits of existing buildings and ensure new 
developments are constructed to consider the 
flood challenges Winthrop faces, along with 
changes that can be made to reduce the Town’s 
contributions to climate change: 
Site-specific adaptations: 
• Site Plan Review should be updated to 
reflect sea level rise and the projected 
flood areas. 
• Resiliency review check-lists for each 
board/commission in town should 
be developed to consider the ability 
of buildings and land to withstand, 
endure, and recover from severe 
weather events and flooding. 
• A special permit process could allow 
existing homes in flood areas to be 
raised above local building height 
limitations. 
Area-wide adaptations: 
• Update Winthrop’s Wetlands 
Protection bylaws to restrict 
vegetation clearing in flood zones 
along coastal areas. 
• Continue to enforce the Town’s 
Floodplain Zoning District and 
associated building regulations for 
floodplain areas. Update this district 
to remain consistent with FEMA 
guidelines and floodplain mapping. 
• Consider creating a new flood zone 
overlay district to regulate new 
construction within 1% chance flood 
areas. 
Town of Winthrop Entrance Sign

10-3 STRATEGIZE: Regulation and Policy 
Policy and Planning 
Climate adaptation presents Winthrop 
with opportunities for carefully managed 
growth and investment that ensure existing 
neighborhoods can thrive, new neighborhoods 
are ready for the changing climate, and 
jobs are created and expertise developed 
for long-term growth and protection. The 
following policies are recommended for Town 
implementation to further prepare for coastal 
flooding and sea level rise in the future. 
• In conjunction with the goals of the 
Open Space and Recreation Plan: 
» Identify coastal lands to be 
protected and pursue acquisition of 
those parcels; 
» Acquire vacant properties in 
identified probable areas of 
flooding 
» Revegetate eroded areas where 
needed with conservation planting 
programs to protect sensitive areas 
as well as enhance the aesthetics of 
the beach areas. 
• A section on Climate Change 
Preparedness could be included in the 
update of the Town’s master plan, to 
develop policy principles and actions 
for climate change preparedness. 
Development of best management 
practices (BMPs) should be considered 
and implemented to encourage 
developers and home owners to follows 
guidance and standards for properties 
in projected flood areas. 
• Town-funded projects could be 
required to incorporate sustainable 
practices to address the probable 
impacts of future coastal storms and 
sea level rise. 
• Site-specific review of community 
facilities in projected flood zones 
should be considered for adaptation 
measures and resilience plans, as 
illustrated in Chapters 8 & 9 . 
• Recent Center Business District (CBD) 
Master Plan could re-evaluate certain 
policies considering probable coastal 
flooding and sea level rise. (e.g. height 
requirements, densities, CBD footprint, 
stormwater/green infrastructure/ 
renewable energy requirements, etc.) 
• Winthrop’s emergency response plan 
should be reviewed, considering 
information provided in this study, to 
prepare for and minimize flood damage 
from coastal storms and sea level 
rise. This would include facility- and/ 
or site-specific instructions (pre-and 
post-storm actions/maintenance), and 
relocating important equipment outside 
of the flood areas. 
• Town should identify groups and 
agencies with special interests in 
Winthrop, and create a special task 
force to identify flood issues and shared 
goals, and work together to achieve 
them. The group could include: 
» Department of Conservation and 
Recreation 
» Massachusetts Water Resources 
Authority 
» Massachusetts Port Authority 
» Community leaders / groups 
» Private land-owners

10-4 STRATEGIZE: Regulation and Policy 
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11-1 STRATEGIZE: Implementation 
11 STRATEGIZE: Implementation 
Every project needs a budget, to meet special 
requirements, and to have funding mechanisms 
in place. The adaptation measures explored 
in Chapters 8 and 9 are reviewed in this 
chapter for cost, permitting, and funding 
to assist Winthrop in moving forward with 
implementation. 
Range of Costs 
Costs for site retrofits have been estimated 
in Table 11-1 . The estimate includes initial 
materials and labor, but not the cost of design, 
permitting, and maintenance. These costs 
can vary depending on the size and location 
of the adaptation measures and should be 
investigated if a specific adaptation measure is 
being considered. 
Table 11-1 Range of costs for Pump Station adaptations 
ADAPTATION TYPE COST ESTIMATE* 
Stop Logs $4,000 - $6,000 each 
Watertight Exhaust Ducts $10,000 - $15,000 each 
Watertight Floor Hatches $10,000 - $15,000 each 
Repoint Building Façade 5-feet above grade $20 - $30 per square foot 
Waterproof Building Façade 5-feet above grade $5 - $10 per square foot 
Raise Outdoor Equipment Pads $500 – $1,000 each 
Raise Electrical Equipment Supports $10 - $20 each 
Work Platforms for Raised Electrical Equipment $50 - $100 each 
5-ft Concrete Perimeter Wall $300 - $500 per linear foot 
* Estimates include approximate cost of materials and labor for installation. Estimates do not include design, permitting, right-of- 
way acquisition, construction mobilization and demobilization, operations, or maintenance. 
Key to Estimated Range of Costs: $ = <$100,000 ; $$ = $100,000 to $500,000 ; $$$ = $500,000 to $3,000,000 ; $$$$ = 
$3,000,000 to $10,000,000 ; $$$$$ = > $10,000,000

11-2 STRATEGIZE: Implementation 
Table 11-2 Range of costs for shoreline / area adaptation 
FLOOD 
AREA 
APPROX. 
2030 
FLOOD 
AREA 
(ACRES) 
CRITICAL PUBLIC 
INFRASTRUCTURE 
1% CHANCE 
FLOOD DEPTH 
(FEET) RECOMMENDED 
ADAPTATION 
CONCEPT 
POTENTIAL 
HEIGHT OF 
INSTALLATION 
(LINEAR FEET) 
POTENTIAL 
LENGTH OF 
INSTALLATION 
(LINEAR FEET) 
MODELED 
EFFECTIVENESS FOR 
FLOOD PROTECTION 
UNDER 1% CHANCE 
FLOOD DEPTH (2030) 
2030 COST OF 
CONSTRUCTION* 
2070 
ADDITIONAL 
COST* 
2030 2070 
Belle Isle 
Marsh 106 
Main Street 
(Evacuation Route 
& Deer Island 
Trucking Route) 
2'-25'' 6' 
Planted berm / elevated 
sidewalk with knee wall 
along Morton Street 
right-of-way. 
1-3" 625 
Relatively ineffective 
solely along Morton 
Street. Needs to extend 
further west & south 
along the inlet. 
$$$ $$$-Engineered 
flood barrier 
Ingleside 
Park 38 Pleasant Street 
(Evacuation Route) 8'' 3'-5'' 
Hybrid seawall, with 
seating & planting 
adjacent to Donovan’s 
Beach. 
1-9" 325 Effective as a coastal 
flood adaptation. $$$ $$-Engineered 
flood barrier 
Lewis 
Lake 153 
Washington Avenue 
(Evacuation Route, 
Winthrop High 
School) 
1'-5'' 4'25'' Flood barrier at 
Washington Avenue. 2-6" 900 
Effective as a coastal 
flood adaptation, if 
culvert & tide gate 
system at Crystal Cove 
work as intended. 
$$$ $$ 
Point 
Shirley 88 
Shirley Street/ 
Tafts Avenue 
(Evacuation & Deer 
Island Trucking 
Route) 
12'' 4' 
Beach nourishment / 
dune creation at Yirrell 
Beach (pending design 
study). Pending design 
study 3,850 
Effective in reducing 
wave overtopping & 
flood depth levels if 
properly engineered. 
$ $$$$$ 
Dune creation at Yirrell 
Beach (pending design 
study). 
$$$$ to $$$$$ $$$$$ 
*Estimates include approximate cost of materials and labor for installation. Estimates do not include design, permitting, right-of-way acquisition, construction mobilization and 
demobilization, operations, or maintenance. Key to Estimated Range of Costs: $ = <$100,000 ; $$ = $100,000 to $500,000 ; $$$ = $500,000 to $3,000,000 ; $$$$ = $3,000,000 
to $10,000,000 ; $$$$$ = > $10,000,000

11-3 STRATEGIZE: Implementation 
Environmental Permitting 
Environmental permitting requirements are 
an important consideration for every project 
and especially for coastal projects proximate 
to natural, cultural, and recreational resources 
along the shoreline. Each adaptation concept 
recommended in this Assessment will require 
some level of environmental permitting under 
public laws. 
Determining the required permitting begins 
with an understanding of environmental 
resources at each adaptation site. The next step 
is to identify location-specific design strategies 
to avoid/minimize construction impacts to 
those resources. The extent of anticipated 
impacts informs the need for specific permits 
which in turn impacts the overall project 
schedule. Each permit has a related agency 
review time frame and some approvals are pre- 
requisites to others. Often the environmental 
permits are on the critical path to advertise a 
project for construction, which emphasizes 
the importance of carefully managing the 
environmental permitting process. 
Table 11-3 outlines potential permits or 
clearances often needed for shoreline 
construction. Early coordination with 
local officials and regulatory agencies is 
recommended to obtain a comprehensive list of 
all required permits at the start of each project. 
In addition to the identified permits, additional 
technical studies may be needed. For example, 
in the Belle Isle Marsh Flood Area, sites south 
of Main Street have a history of oil and hazard 
material releases. Soil testing is recommended 
in this area, and state approvals identifying 
appropriate disposal methods and locations 
may be required. Likewise, in the Point Shirley 
Flood Area, recently released Natural Heritage 
and Endangered Species Program (NHESP) 
mapping shows potential habitat for protected 
species such as the Grasshopper Sparrow, 
Upland Sandpiper, Piping Plover, Common 
Tern, and Lest Tern. Potential species and 
habitat field assessments may be needed to 
verify the absence/presence of these species in 
each project area. 
When the Town is applying for funding 
for these projects, the timelines associated 
with each permit should be factored into the 
proposed project schedule. This includes the 
agency review time frames for each permit/ 
approval and any Time of Year restrictions 
placed on the project which may impact the 
construction schedule. Depending on the 
funding program, it may be necessary to 
phase the project over a few funding cycles 
to account for the permitting time frames. 
For example, propose preliminary design 
and some permitting in year one, final design 
and permitting in year two, and construction 
starting in year three. The phasing strategy will 
vary depending upon the funding cycles and 
required period of performance. 
Flagging salt marsh boundaries at Coughlin Park, Summer 2016, Source: Woods Hole Group

11-4 STRATEGIZE: Im 
ENVIRONMENTAL PERMIT OR APPROVAL (AGENCY) 
FLOOD AREA 
Recommended Adaptation Measure/Location & Environment 
Belle Isle Marsh 
Planted Berm with Sidewalk 
Along Morton Street 
Ingleside Park 
Hybrid sea wall, with seating 
and planting adjacent to 
Donovan’s Beach 
Lewis Lake 
Flood barrier 
at Washington 
Avenue 
LOCAL 
Notice of Intent (NOI) / Order of Conditions (OOC) 
Massachusetts, M.G.L. c.131, §40 and the Winthrop Wetlands 
Protection Ordinance 
(Winthrop Conservation Commission and MassDEP) 
• • • 
STATE 
Massachusetts Environmental Policy Act (MEPA) – Environmental 
Notification Form (ENF) 
M.G.L. c. 30, §61-62H 
(MA Executive Office of Energy and Environmental Affairs) • 
Massachusetts Endangered Species Act (MESA) - Project Review 
M.G.L c.131A 
(Natural Heritage and Endangered Species Program of the 
MA Department of Fish & Wildlife) 
• 
Section 106 / Chapter 254 Historic Review - Project Notification Form 
(PNF) 
S ection 106 of the National Historic Preservation Act of 1966 / 
M.G.L. c. 9, §§ 26-27C as amended by St. 1988, c. 254 
(Massachusetts Historical Commission) 
• • • 
Section 401 Water Quality Certification (WQC) 
Federal Water Pollution Control Act, 33 U.S.C. 1341 et seq., 
§401 / Massachusetts Clean Water Act, M.G.L. c. 21, §26-53 
(MassDEP) 
If impacts to wetland resources 
/ Mean High Water exceed 
thresholds 
If impacts to wetland resources 
/ Mean High Water exceed 
thresholds 
If impacts 
to wetland 
resources / Mean 
High Water exceed 
thresholds 
Chapter 91 Water Dependent License or Permit 
Public Waterfront Act, M.G.L. c. 91 
(MassDEP) 
• • 
FEDERAL 
Coastal Zone Management (CZM) Federal Consistency Review 
Federal Coastal Zone Management Act, 16 U.S.C. §1451 et 
seq./ Massachusetts Coastal Zone Management Act, M.G.L. 
c. 21A, §2, 4 
(MA Office of CZM) 
Section 404 Massachusetts General Permits (GP) from U.S. Army Corps 
of Engineers (USACE) – Preconstruction Notification (PCN) 
Federal Clean Water Act, 33 U.S.C. c. 1344 §404 et seq. / 
Rivers and Harbors Act, 33 U.S.C. c.403 §10 
(US Army Corps of Engineers, New England District) 
If impacts below 
Mean High Water 
If impacts below 
Mean High Water 
If impacts below 
Mean High Water 
Table 11-3 Potential Permits Needed for Shoreline Construction

11-5 plementation 
al Resources 
ACTION PROCESS 
Point Shirley 
Beach Nourishment / dune 
creation along Yirrell Beach 
• Temporary or permanent alteration of wetland resource 
areas and/or work in a regulated buffer to these areas. 
Submit NOI application to local Conservation 
Commission. Copy mailed to MassDEP Northeast 
Region Office. Requires abutter mailings, legal 
notice, site visit, and public hearing. 
• 
Exceed MEPA review thresholds and require a permit from a 
State agency /department / board / commission / authority 
or utilize state funds. Potential thresholds include work within 
an Area of Critical Environmental Concern (Rumney Marsh) 
and alteration of barrier beach (Yirrell Beach) or salt marsh 
(Donovan’s Beach), for example. 
Submit ENF to EEA. Copies mailed to MEPA directed 
distribution list. Notice published in Environmental 
Monitor and local newspaper. A site visit is typically 
held. 
• 
Work within mapped areas of priority and estimated habitat 
(14th Edition Natural Heritage Atlas, draft). 
Submit Project Review Form or file for Streamlined 
NOI/MESA review to show the project does not result 
in “Take” of habitat, or provides mitigation for habitat 
impacts. 
• 
Requires funding, licenses, or permits from any state or federal 
governmental agency. 
Submit PNF to MHC. Copies mailed to MA Bureau of 
Underwater Archeological Resources, Tribal Historic 
Preservation Officer, and local historic commission 
(as appropriate). 
If impacts to wetland resources 
/ Mean High Water exceed 
thresholds 
If a project impacts more than 5,000 square feet of wetlands, 
or requires more than 100 cubic yards of dredging, MA DEP 
must review its compliance with state water quality standards. 
Submit WQC application to MassDEP with sediment 
analysis (for dredging). Public Notice published in 
local newspaper. A complete application includes 
Tthe following approvals: OOC, MEPA Certificate (as 
appropriate). 
• 
Licenses required for any project located in, on, over, or 
under tidal waters (flowed tidelands) or filled tidelands. 
Permits are required for dredging. 
Submit new or amended Chapter 91 license or 
permit application to MassDEP. Public Notices mailed 
to abutters and state agencies, and published in 
local newspaper. A complete application includes 
the following approvals: OOC, WQC, and MEPA 
Certificate. 
If impacts below 
Mean High Water 
Project within a coastal zone requires funding, licenses, 
or permits from any federal governmental agency. CZM 
Consistency Review ensures compliance with standards of 
the MA CZM plans . 
Complete a federal consistency application to 
describe how the project is consistent with relevant 
CZM program policies. Requires public notice & 
decisions on all applicable state licenses /permits 
If impacts below 
Mean High Water 
Fill/excavation in wetlands and waterways (Section 404). 
Project must meet a detailed set of criteria for each type of 
construction activity in, on, or over aquatic environments to 
receive the GP. 
Submit PCN to Corps New England District. Corps 
publishes a Public Notice. A complete application 
includes the following approvals: MHC sSection 106, 
MESA, OOC, WQC, Ch.91.

11-6 STRATEGIZE: Implementation 
Potential Funding Sources 
The adaptation strategies discussed in 
this assessment vary in terms of probable 
construction costs and implementation 
timeline. They include combination of green 
and gray elements, and depending on the 
location, will help protect specific sites, areas 
of Town, and/or broader regional priorities. 
As these strategies vary, so will the approach 
to funding. The Town should set aside some 
funds in the capital budget to help advance 
some of the smaller scale strategies and/or 
serve as a match to other grant programs. The 
ability to leverage funds for the recommended 
adaptation strategies will depend on the 
availability of funding, and the ability to 
phase each strategy to meet identified funding 
targets. 
Potential programs and project partners 
could include a combination of federal and 
state agencies, financial institutions, property 
owners, and non-profit foundations. 
Federal and state agencies release various 
funding opportunities. The availability and 
focus of these funding programs vary from 
year to year based on administration priorities 
and budgets. These programs have been, 
and will continue to be, highly competitive. 
Winthrop has been fortunate in prior years 
to have received grants for various types of 
infrastructure improvement projects. Some of 
these grants have been specifically focused 
on infrastructure resilience such as the Point 
Shirley Drainage Improvements and Coughlin 
Park Green Infrastructure Study, as well as 
the completion of this assessment. In addition, 
state agencies and quasi-state agencies such as 
DCR and MWRA are funding infrastructure 
improvements to upgrade their facilities 
located within the Town. 
Potential federal and state partners and 
programs include: 
• FEMA Hazard Mitigation Assistance 
Program 
• NOAA Sea Grant Program and Coastal 
Ecosystem Resiliency grants 
• U.S. Fish & Wildlife Service Coastal 
Resilience Program grants 
• Massachusetts Coastal Resilience 
grants 
• Massachusetts Dam and Seawall 
Repair and Removal Fund 
• Massachusetts Seaport Economic 
Council grants 
• MassWorks Infrastructure Program 
Funding assistance from financial institu - 
tions can take on various forms. MassDevel - 
opment (a quasi-state real estate financing 
agency) has state-wide authority to create and 
fund Property Assessed Clean Energy (PACE) 
finance programs, making it easier for mu - 
nicipalities to structure C-PACE financing for 
properties in their town and allow renewable 
energies to grow in Massachusetts. In the fu - 
ture, the Massachusetts PACE program could 
be broadened from a renewables focus to 
also include resilience investments similar to 
what Connecticut is doing. The Connecticut 
commercial and residential PACE programs, 
C-PACE and R-PACE respectively, provide 
access to private financing for qualifying re - 
siliency investments—including hurricane and 
flood-proofing.

11-7 STRATEGIZE: Implementation 
At the local level, Massachusetts 
municipalities also sell bonds to financial 
institutions to borrow money needed to 
pay for improvements to various municipal 
assets ranging from buildings and facilities to 
roadway infrastructure to emergency response 
equipment. In addition to Massachusetts 
Municipal Bonds (‘munis’), there are also 
topic focused bonds such as green bonds, that 
fund a specific project or type of project. The 
Town could consider bonding the design and 
construction of a specific adaptation as part of 
a future bond program. 
The Town should also be proactive in its 
efforts to work with property owners to 
integrate resilient design elements into future 
development and redevelopment projects. 
These property owners include private 
residential and commercial owners, as well 
as public agencies such as the DCR and 
MWRA. The probability of coastal flood 
mapping ( Appendix D ) and site adaption types 
(Chapter 8 ) will help these owners make more 
informed decisions about the desired level 
of protection. A particular group of owners 
in one part of Town may also be interested 
in pooling together their financial resources 
to help protect their properties. Some of the 
funding programs available to the Town, such 
as FEMA’s Hazard Mitigation Assistance 
Program. can also help fund adaptation 
strategies at a property scale. The Town should 
make property owners aware of funding 
opportunities as they become available. 
Non-profit foundations may also be interested 
in supporting the Town’s resilience efforts. 
Entities such as the Kresge Foundation, Barr 
Foundation, and Rockefeller Foundation are 
funding climate-resilience planning and design 
efforts with local and non-profit partners in the 
metro-Boston area. These foundations support 
projects that take an integrated approach to 
building community resilience. The strategies 
and grantmaking priorities of each foundation 
change in response to internal interest areas 
and national trends. 
If the municipal budget can’t support the 
required level of investment and bonding 
is not an option, the Town could consider 
implementing District Improvement 
Financing (DIF, geographic focused) or 
a Stormwater Utility (topic focused). 
Essentially these financing mechanisms 
impose a supplemental benefit assessment on 
the owner’s property tax for a specific purpose. 
Each of these mechanisms are allowable 
under Massachusetts law and often involve 
complementary zoning updates. 
The major takeaway – the Town will need 
to be creative in its approach to funding 
adaptation strategies. Infrastructure adaptation 
at a Town-wide level is expensive and will 
need to be phased over time as new projects 
or upgrades are proposed, or as standalone 
projects as funding allows. Public-private 
partnerships may prove beneficial to advancing 
these strategies in the near term.

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12-1 STRATEGIZE: Next Steps 
Sunrise from Winthrop Beach 
This assessment lays the framework for 
Winthrop’s efforts to build community 
resilience. The Town has systematically 
identified, prioritized, and strategized areas 
of Town and critical infrastructure most at 
risk of coastal flooding under present day and 
future climate conditions. The next step is to 
advance the assessment recommendations and 
expand the resilience discussion to include 
consideration of other climate-related hazards 
and community assets. 
12 STRATEGIZE: Next Steps 
The next steps to advance the assessment 
recommendations include: 
• Remain active in the Boston Metro 
Mayors Coalition Climate Preparedness 
Task Force 
• Review the Boston Harbor Flood 
Barrier Study being led by UMass 
Boston working for the Barr 
Foundation 
• Educate residents and business owners 
on how they can prepare for coastal 
flooding now and in the future 
• Be proactive in integrating resilient 
design elements into future public 
and private development and 
redevelopment projects

12-2 STRATEGIZE: Next Steps 
workshop process will identify key climate- 
related hazards, vulnerabilities and strengths, 
develop adaptation actions, and prioritize next 
steps. Results of the workshop and planning 
efforts will be used to inform existing local 
plans, grant applications, budgets, and policies. 
The Town-wide mapping and evaluation of 
coastal flooding completed as part of this 
assessment will be beneficial to the workshop 
process. 
Again, the takeaway is that the Town does not 
need to do this alone or all at once. While the 
impacts of climate change are already being 
felt locally, the Town’s ability to respond to 
increased coastal flooding and other climate- 
related hazards will take time and funding. 
Most importantly, improving community 
resilience will require a commitment from the 
Town, its residents and business owners, and 
agency partners to advance a multilayered 
resilience strategy. 
• Set aside funds in the Town’s capital 
budget for the recommended adaptation 
measures 
• Phase adaptation measures based 
on synergies with other capital 
improvement projects and funding 
availability 
• Pursue grants and other funding 
opportunities to leverage town funds 
In addition, in Fall 2017, the Town will begin 
a community resilience building workshop 
process as part of the Commonwealth’s 
Municipal Vulnerability Preparedness 
(MVP) Program . This Program expands the 
focus from just coastal flooding to include 
consideration of other climate-related hazards 
such as increased precipitation and heat, for 
example. It will also expand the discussion 
to include a comprehensive assessment of 
infrastructural, societal, environmental, and 
economic components of the Town. The 
workshop process will follow a similar 
identify-prioritize-strategize framework. The

A-1 
Appendix A - Glossary of Terms 
and Abbreviations 
Terms 
1% CHANCE FLOOD DEPTH The depth of flooding relative to sea level and storm surge during a 
100 year storm event. 
1% CHANCE WATER LEVEL/ 
SURFACE ELEVATION 
The probable water elevation from a storm event that occurs ever 
100 years. 
ADAPTATION Adjustment or modification to a particular situation or circumstance. 
DRY FLOODPROOFING 
Protecting a building from floodwaters by creating an impermeable 
barrier on the outside. (ex. Flood doors, watertight access hatches, 
and wall and floor sealants) 
EXECUTIVE ORDER 569 
Executive Order signed by Governor Baker, which lays out an 
approach to further reduced greenhouse gas emissions, safeguard 
residents, municipalities and business from the impacts of climate 
change, and build a more resilient Commonwealth. 
COASTAL GREEN 
INFRASTRUCTURE 
Built ecological systems and processes intended to absorb wave 
energy, reduce erosion, and improve water quality. Coastal 
examples include constructed wetlands, urban forests, green roofs, 
green streets, living shorelines, and rain gardens. 
COASTAL GRAY INFRASTRUCTURE Engineered coastal structures, including seawalls, bulkheads, and 
stone revetments. 
COASTAL HYBRID 
INFRASTRUCTURE 
A combination of green and gray infrastructure. Coastal examples 
include coastal wetland plantings and berms with engineered walls. 
HYDRODYNAMIC MODELING 
Modeling based on mathematical representations of the processes 
that affect coastal water levels such as riverine flows, tides, waves, 
winds, storm surge, sea level rise, and wave set-up, at a fine 
enough resolution to identify site specific locations that may require 
adaptation alternatives. 
INUNDATION The flooding of low-lying coastal land caused by severe weather. 
KING TIDE 
The highest predicted high tide of the year at a coastal location. It 
is above the highest water level reached at high tide on an average 
day. 
PERIMETER BARRIER Permanent or temporary vertical structure that surrounds a particular 
asset to deter waters. 
RESILIENCE 
The capability to anticipate risk, limit impact, and bounce back 
rapidly through survival, adaptability, evolution, and growth in the 
face of ... change. (Definitions of Community Resilience: An Analysis - 
A CARRI REPORT)

A-2 
RISK SCORE 
(Consequence of Failure x Probability of Flooding) - Score to prioritize 
infrastructure assets/facilities. Rated through a five-tier qualitative 
rating system (Severe to None). 
STORM SURGE An abnormal rise of water generated by a storm, over and above 
the normal tide ranges. 
VULNERABILITY 
Structures, systems, populations or other community assets as defined 
by the community that are susceptible to damage and loss from 
hazard events. (FEMA Local Mitigation Plan Review Guide 2011) 
WET FLOODPROOFING 
Allows an asset to withstand flooding, and recover more quickly after 
the water has receded (ex. Building with flood resistant materials and 
anchoring equipment. 
Abbreviations 
ADCIRC Advanced Circulation 
AUL Activity and Use Limitation 
BH-FRM Boston Harbor-Flood Risk Model 
BMPS Best Management Practices 
CBD Center Business District 
CIP Capital Improvement Program 
CZM Massachusetts Office of Coastal Zone Management 
DCR Department of Conservation and Recreation 
DIRP Disaster Infrastructure Resiliency Plan 
DPW Department of Public Works 
ENF Environmental Notification Form 
EEA Executive Office of Energy and Environmental Affairs 
FEMA Federal Emergency Management Agency 
FHWA Federal Highway Administration 
FIRM Flood Insurance Rate Map 
GIS Geographic Information Systems 
LIDAR Light Detection and Ranging 
MA CZM Massachusetts Office of Coastal Zone Management 
MASSDOT Massachusetts Department of Transportation 
MASSGIS Massachusetts Office of Geographic Information 
MASSPORT Massachusetts Port Authority 
MBTA Massachusetts Bay Transportation Authority 
MEPA Massachusetts Environmental Policy Act 
MESA Massachusetts Endangered Species Act

A-3 
MORIS Massachusetts Ocean Resource Information System 
MVP Municipal Vulnerability Preparedness 
MWRA Massachusetts Water Resources Authority 
NHESP Natural Heritage and Endangered Species Program 
NOAA National Oceanic and Atmospheric Administration 
NOI Notice of Intent 
OOC Order of Conditions 
PCN Preconstruction Notification 
PMT Winthrop Project Management Team 
PRV Pressure Reducing Valve Station 
SCADA Supervisory Control and Data Acquisition 
SLAMM Sea Level Affecting Marshes Model 
SLR Sea Level Rise 
SWAN Simulating Waves Nearshore 
USACE U.S. Army Corps of Engineers 
WHG Woods Hole Group 
WQC Water Quality Certification

A-4 
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A-5 
Appendix B - References 
Amtrak. Amtrak NEC Climate Change Adaptation Plan – Phase III Pilot Study . March 2017. 
AxisGIS. “ Winthrop Assessment Data .” CAI AxisGIS, https://www.axisgis.com/winthropma/ . 
Baldwin, Sandy. “ Boston Harbor Pipe Dreams Come True! USGS Visits the Deer Island Sewage 
Treatment Plant and a Cleaner Harbor. ” Sound Waves , USGS, Apr. 2006. Web. 15 Mar. 2017. 
https://soundwaves.usgs.gov/2006/04/staff.html 
Bourne Consulting Engineering, with Childs Engineering Corporation. Massachusetts Coastal 
Infrastructure Inventory and Assessment Project ; Massachusetts Department of Conservation and 
Recreation (DCR) Office of Waterways. 6 Jun 2009. 
Cecil Group. Winthrop Harbor Assessment and Plan . April 2005. 
City of Boston. Climate Ready Boston, Final Report . December 2016. 
Clark, William H. The History of Winthrop Massachusetts 1630-1952 . http://www. 
winthropmemorials.org/civic/pages/history-of-winthrop-clark.html 
Culhane, Kerri, Jordan Fink, and Tabitha Kaigle; Conway School of Landscape Design. 
Walk Winthrop: A Plan for a More Walkable Community . 31 Mar 2010. https://issuu.com/ 
conwaydesign/docs/walkwinthrop_2010 
DeCosta-Klipa, Nik. “ What’s a King Tide and Why Are They Flooding Boston’s Waterfront? ” n.d.: 
n. pag. Boston.com. The Boston Globe, 18 Oct. 2016. Web. 13 Mar. 2017. 
Domelowicz, Joseph. “ National Grid Is in the Final Stages of Substation Upgrade. “Winthrop 
Transcript. Wordpress, 14 Jan. 2011. Web. 15 Mar. 2017. http://www.winthroptranscript. 
com/2011/01/14/national-grid-is-in-the-final-stages-of-substation-upgrade/ 
Executive Office of Energy and Environmental Affairs (EOEA) and the Adaptation Advisory 
Committee. Massachusetts Climate Change Adaptation Report , September 2011. 
Federal Emergency Management Agency. “ Hazard Mitigation Planning .” 6 Feb 2017. 
Form + Place, Inc. Town of Winthrop Centre Business District Master Plan . March 2017. 
Friends of Winthrop Beach. “ Winthrop Beach History. ” http://winthropbeach.org/winthrop- 
beach-project-history/

A-6 
Lynds, John. “ Belle Isle Bridge Officially Complete. ” East Boston Times Free Press. Wordpress, 
28 Aug. 2013. Web. 15 Mar. 2017. 
Massachusetts Bay Transportation Authority (MBTA). Ridership and Service Statistics. 
Fourteenth Edition, 2014 . http://www.mbta.com/uploadedfiles/About_the_T/Panel/ 
MBTARidershipandServiceStatistics2014.pdf 
Massachusetts Department of Conservation and Recreation (DCR). “ Winthrop Beach 
Renourishment / Rumney Marsh Restoration. ” http://www.mass.gov/eea/agencies/dcr/ 
conservation/planning-and-resource-protection/projects/winthrop-beach-renourishment-project. 
html 
M.G.L. ch.90 §61 https://malegislature.gov/Laws/GeneralLaws/PartI/TitleXIV/Chapter90/ 
Section61 
Massachusetts Historical Commission (MHC). MHC Reconnaissance Survey Report: Winthrop. 
Boston, Massachusetts, 1981. 
Massachusetts Office of Coastal Zone Management (CZM). “ Massachusetts StormSmart 
Coasts. ” http://www.mass.gov/eea/agencies/czm/program-areas/stormsmart-coasts/ 
Massachusetts Office of Geographic Information (MassGIS). “ 2010 U.S. Census – 
Environmental Justice Populations. ” December 2012. http://www.mass.gov/anf/research-and- 
tech/it-serv-and-support/application-serv/office-of-geographic-information-massgis/datalayers/ 
cen2010ej.html 
Massachusetts Water Resources Authority (MWRA). “ Drinking Water Test Results for 2012. ” 
June 2013. http://www.mwra.state.ma.us/annual/waterreport/2012results/metro.htm 
Massachusetts Port Authority. “ Massport Board Approves Funding to Begin Boston Harbor 
Dredging Project .” 24 Mar. 2016. http://www.massport.com/massport/media/newsroom/ 
massport-board-approves-funding-to-begin-boston-harbor-dredging-project/ 
Massachusetts Water Resources Authority (MWRA). “ Sewer Sections 4, 5, 6 and 186 Study - 
Scope of Services, Contract No. 7423 ”. 22 Sept. 2016. 
Massachusetts Water Resources Authority (MWRA). “ The Deer Island Sewage Treatment 
Plant. ” 2 Sept. 2009. http://www.mwra.state.ma.us/03sewer/html/sewditp.htm 
McGregor & Associates, P.C. T own of Winthrop Open Space and Recreation Plan 2005-2010 . 
January 2005. http://www.town.winthrop.ma.us/sites/winthropma/files/uploads/osrpfinaldraft.pdf 
Metropolitan Area Planning Council (MAPC). Town of Winthrop Hazard Mitigation Plan 2014 
Update . 7 April 2015. 
Metropolitan Area Planning Council (MAPC). “ Metro Mayors Coalition. ” http://www.mapc.org/ 
metro-mayors-coalition

A-7 
Metropolitan Area Planning Council (MAPC). Walk Winthrop: A Greenway Action Plan. 21 Nov. 
2011. 
Metropolitan Area Planning Council (MAPC) and the Central Transportation Planning Staff. 
Winthrop Community Development Plan, May 2004 . 
National Flood Insurance Program. “ Coastal Flooding: Maps & Changes. ” Coastal Flood Maps. 
27 Sept. 2016. Web. 13 Mar. 2017. 
National Science and Technology Council. Ecosystem-Service Assessment: Research Needs for 
Coastal Green Infrastructure . August 2015. 
Schworm, Peter and Martin Finucane, Globe Staff. “ Hurricane Sandy Slams East Coast. ” 
10.29.12 | 11:19 PM, http://archive.boston.com/ accessed 3/6/2017 
Town of Winthrop. “ Town Landing Complex. ” n.d. Web. 15 Mar. 2017. https://www.town. 
winthrop.ma.us/harbormaster-department/pages/town-landing-complex-0 . 
Town of Winthrop. “ Winthrop Air Pollution, Noise, and Airport Hazards Committee. ” n.d. 
Web. 15 Mar. 2017. http://www.town.winthrop.ma.us/winthrop-air-pollution-noise-and-airport- 
hazards-committee 
Town of Winthrop. “ Town of Winthrop Ferry News & Announcements. ” https://www.town. 
winthrop.ma.us/node/20703/news 
Tnmec Company Incorporated. “ Winthrop Standpipe. ” https://www.tnemec.com/resources/ 
project/429/Winthrop_Standpipe.pdf 
U.S. Census Bureau. “ QuickFacts; Winthrop, Massachusetts. ” https://www.census.gov/ 
quickfacts/table/AGE295215/2581005 
U.S. Environmental Protection Agency (EPA). “ King Tides and Climate Change. ” https://www. 
epa.gov/cre/king-tides-and-climate-change

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A-9 
Appendix C - Inundation 
Modeling 
Overview 
In order for the Town of Winthrop to effectively evaluate the risks of climate change, and specifically 
sea level rise and storm surge, to their coastal community and public assets, a scientifically 
accurate, dynamic, robust, and probability based analysis of potential flooding is a key element of 
a vulnerability assessment. This allows for the Town to identify and prioritize potential impacted 
areas and assets, and then determine potential adaptation options to build overall resilience for 
the community. Using established techniques and previously generated model data from work 
with Massachusetts DOT, probabilistic flood information forms the basis for the vulnerability 
assessment in the Town of Winthrop. 
The Boston Harbor Flood Risk Model 
Although there are various options for modeling sea level rise and storm surge, the most accurate 
approach for assessing combined storm surge risk and sea level rise conditions is through the 
implementation of hydrodynamic models that include the physical processes that are associated 
with storm climatology and propagation. The model, called the Boston Harbor Flood Risk Model 
(BH-FRM) is the model used to provide the results for the Town of Winthrop. Data from the 
Boston Harbor Flood Risk Model (BH-FRM) has been successfully applied and used in Boston, 
MA and the Boston Harbor Area for assessing potential vulnerabilities in the Central Artery tunnel 
system. 
The BH-FRM was a joint collaboration between MassDOT, Woods Hole Group, and UMass 
Boston under a FHWA grant that aimed to assess the vulnerability of the Central Artery/Tunnel 
Project (CA/T) to climate change (specifically SLR and storm surge). As one of the most valuable 
components of Massachusetts’ transportation infrastructure, its maintenance, protection and 
enhancement were a priority for the Commonwealth. The importance of modeling potential effects 
of sea level rise and storm surge for the CA/T was especially evident after Hurricane Sandy hit the 
New York Coastline, which had devastating impacts to vital transportation and city infrastructure. 
Concern about potential impacts to the City of Boston from future storms drove the creation of 
the BH-FRM – a model with the best representation of the physical processes, as well as accurate 
and higher resolution predictions of inundation due to the combination of sea level rise and storm 
surge. The hydrodynamic modeling utilized for the BH-FRM was geared towards a physics-based 
approach to determine the water level increases and flooding, and provided results to identify 
specific locations that may require adaptation alternatives.

A-10 
BH-FRM Components 
BH-FRM is a comprehensive flood risk model that can accurately assess flooding risk under present 
day and future climate change conditions. The modeling system is comprised of the Advanced 
CIRCulation model (ADCIRC), a two-dimensional, depth-integrated, long wave, hydrodynamic 
model for coastal areas, inlets, rivers and floodplains that in this application is used to predict 
storm surge flooding; and the unstructured grid version of Simulating Waves Nearshore model 
(UNSWAN), a wave generation and transformation model. The ADCIRC model is tightly coupled 
with UNSWAN, dynamically exchanging physical processes information during each time step, 
to provide an complete and accurate representation of water surface elevations, winds, waves, 
velocities, and flooding along the coastline and upland areas. 
The model explicitly and quantitatively incorporates climate change influences on sea level 
rise, tides, waves, storm track, and storm intensity. The model computations use a site-specific 
model grid that covers the coast line and open water of the Boston Harbor but also propagated 
overland. This grid was developed by interlacing multiple meshes with varying grid resolution 
(coarse, intermediate and fine) and resulted in a mesh that could capture all critical topographic 
and bathymetric features that influence flow dynamics within the system. The resulting mesh 
has a resolution of 10 meters or less (as low as 2-3 meters in the CA/T study area), and was 
developed using topographic and bathymetric data from the Boston Harbor area. A variety of 
boundary conditions were set before modeling could begin and included (but were not limited 
to) tidal constituents, freshwater input, bottom friction, direction wind reduction, and even the 
understanding dam operations in the area influence flood control. 
Model Calibration and Validation 
While the models used in the BH-FRM pilot project are rooted in sound science and utilized 
standard governing equations of water motion, the propagation of water through a unique geographic 
setting results in site-specific variations that may require adjustment of model parameters to more 
accurately represent the real-world system. For example, in an urban landscape, an area consisting 
of numerous buildings will influence flow differently than a marsh, which will influence flow 
differently than a parking area, which will influence flow differently than a sub-tidal estuary. For 
these types of cases, it is reasonable to adjust parameters, such as frictional factors within accepted 
bounds to better represent the water propagation. As such, the BH-FRM model was calibrated 
using both normal tidal conditions and representative storm events for the northeast (Blizzard of 
1978). The calibrated model was then validated to another storm event (Perfect Storm) to ensure 
accuracy.

A-11 
Sea Level Rise and Storm Climatology 
Sea level rise modeling scenarios in BH-FRM include 2030 and 2070 time horizons. The SLR 
scenarios bracket ranges that span multiple time horizons consistent with scenarios from the United 
States National Climate Assessment (Parris et al, 2012). The final SLR values were adjusted for 
local subsidence following Kirshen et al. (2008). Local subsidence is approximately 1.1 mm/year 
or approximately 0.4 feet per 100 years. The SLR projections used for 2030 and 2070 in the BH- 
FRM were 0.62 feet (19 cm) and 3.2 feet (30 cm) respectively. 
The BH-FRM also models a statistically-robust sample of storms, including tropical (hurricanes) 
and extra-tropical (nor’easters) and is based on the region’s existing and evolving climatology. 
Tropical storms were specifically selected based on a screening process that evaluated storm tracks 
capable of entering the northeast area, thereby potentially impacting the Boston Harbor region. 
However, tropical storms are less common in the Northeast, therefore, it was critical to develop a 
series of extra tropical storms for simulation in BH-FRM. Existing and historical meteorological 
and water level data was used to pair storm surge events with individual storms to identify specific 
extra-tropical storms that were or could be typical for the Boston Harbor area. 
The probabilistic modeling approach simulates a statistically robust set of storms (both tropical 
and extra-tropical) for each climate change and/or Sea Level Rise (SLR) scenario through a 
Monte Carlo statistical approach. Results of the Monte Carlo simulations are used to generate 
Cumulative Probability Distribution Functions (CDFs) of the storm surge water levels at a high 
degree of spatial precision. In particular, an accurate and precise assessment of the exceedence 
probability of combined SLR and storm surge, provided at high spatial resolution help decision 
makers identify areas of existing vulnerability requiring immediate action, as well as, areas that 
benefit from present planning for future preparedness. Results of the Monte Carlo approach also 
produce a statistically robust, spatially variable map of risk for each given SLR scenario that can 
be used to determine the potential need for adaptation, and the timing for potential adaptation, at 
each facility and for each infrastructure asset. 
For more information regarding the specific inputs and computational capabilities of the BH-FRM, 
refer to the MassDOT-FHWA Pilot Project Report .

A-12 
BH-FRM Outputs 
Flood exceedance probability is defined as the probability of flood water encroaching on the land 
surface at a particular location for a given climate time frame. Maps show flood exceedance 
probabilities across Winthrop for near future climatic conditions (represented by the 2030 scenario) 
and late 21 st century conditions (represented by the 2070 scenario). Exceedance probabilities 
shown on these maps range from 0.1% (0.001, otherwise known as the 1000-year flood level) 
to 100% (the annual storm water surface elevation level). These maps can be used to identify 
locations, structures, assets, etc. that lie within different risk levels within the area. For example, 
a building that lies within the 2% flooding exceedance probability zone would have a 2% chance 
of flooding in that year (under the assumed climatology). In other words, in each year there is a 
2% percent chance that this location will get wet. Stakeholders can then determine if that level of 
risk is acceptable, or if some action may be required to improve resiliency, engineer an adaption, 
consider relocation, or implement an operational plan. 
By comparing the 2030 flood probability map to the 2070 flood probability map, individual 
structures, assets, and areas can be assessed to determine how flooding is changing as a function 
of time and the overall influence of climate change projections can also be evaluated. These maps 
can also be used to assess flood entry points and pathways and thereby identify potential regional 
adaptations. 
The probability of flooding maps provide stakeholders the ability to determine if areas, buildings, 
etc. are expected to be flooded and at what probability flooding is expected to be initiated. This 
is important for weighing the tolerance for risk and evaluating when adaptation options may need 
to be considered. Perhaps equally as important is the magnitude, or depth, of flooding expected. 
Therefore, depth of flooding map can be created for any given flooding probability level. For the 
Town of Winthrop, 1% (100-yr) and 0.1% (1000-yr) depth maps have been created showing flood 
depths (at 0.5 ft increments). As such, the depth of flooding can also be evaluated when assessing 
the risk to a system.

A-13 
Appendix D - Boston Harbor Flood 
Risk Model (BH-FRM) Mapping

A-14 
Areas of Probable Flooding (2013) 
River Road 
Washington Avenue (Route 145) 
Shirley Street 
Main Street 
Veterans Road 
Revere Street 
Winthrop Shore Drive 
Tafts Avenue 
Court Road 
Winthrop Street 
Pauline Street 
Cross Street 
Shirley Street 
Broad Sound 
Crystal Cove 
Belle Isle 
Inlet 
Boston Harbor 
Belle Isle Marsh 
Broad 
Sound 
Pleasant Street

A-15 
Areas of Probable Flooding (2030) 
River Road 
Washington Avenue (Route 145) 
Shirley Street 
Main Street 
Veterans Road 
Revere Street 
Winthrop Shore Drive 
Tafts Avenue 
Court Road 
Winthrop Street 
Pauline Street 
Cross Street 
Shirley Street 
Broad Sound 
Crystal Cove 
Belle Isle 
Inlet 
Boston Harbor 
Belle Isle Marsh 
Areas of Probable Flooding (2030) 
Pleasant Street

A-16 
Areas of Probable Flooding (2070) 
River Road 
Washington Avenue (Route 145) 
Shirley Street 
Main Street 
Veterans Road 
Revere Street 
Winthrop Shore Drive 
Tafts Avenue 
Court Road 
Winthrop Street 
Pauline Street 
Cross Street 
Shirley Street 
Broad Sound 
Crystal Cove 
Belle Isle 
Inlet 
Boston Harbor 
Belle Isle Marsh 
Areas of Probable Flooding (2070) 
Pleasant Street

A-17 
Depth of Flooding (2013) 
River Road 
Washington Avenue (Route 145) 
Shirley Street 
Main Street 
Veterans Road 
Revere Street 
Winthrop Shore Drive 
Tafts Avenue 
Court Road 
Winthrop Street 
Pauline Street 
Cross Street 
Shirley Street 
Broad Sound 
Crystal Cove 
Belle Isle 
Inlet 
Boston Harbor 
Belle Isle Marsh 
Depth of Flooding - 1% Chance Water Level (2013) 
Pleasant Street

A-18 
Depth of Flooding (2030) 
River Road 
Washington Avenue (Route 145) 
Shirley Street 
Main Street 
Veterans Road 
Revere Street 
Winthrop Shore Drive 
Tafts Avenue 
Court Road 
Winthrop Street 
Pauline Street 
Cross Street 
Shirley Street 
Broad Sound 
Crystal Cove 
Belle Isle 
Inlet 
Boston Harbor 
Belle Isle Marsh 
Depth of Flooding - 1% Chance Water Level (2030) 
Pleasant Street

A-19 
Depth of Flooding (2070) 
River Road 
Washington Avenue (Route 145) 
Shirley Street 
Main Street 
Veterans Road 
Revere Street 
Winthrop Shore Drive 
Tafts Avenue 
Court Road 
Winthrop Street 
Pauline Street 
Cross Street 
Shirley Street 
Broad Sound 
Crystal Cove 
Belle Isle 
Inlet 
Boston Harbor 
Belle Isle Marsh 
Depth of Flooding - 1% Chance Water Level (2070) 
Pleasant Street

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A-21 
Appendix E - Probability of 
Exceedance Curve Data 
BEACH FIRE STATION 
APPROX. CRITICAL 
ELEVATION (FT) 7.12 
2013 2030 2070 
EXCEEDANCE PROBABILITY 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH 
(FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
0.1 wet <0.5 wet 1.0-1.5 wet 4.0-4.5 
0.2 wet < 0.5 wet 1.0-1.5 wet 3.5-4.0 
0.5 wet < 0.5 wet 1.0-1.5 wet 3.5-4.0 
1 wet < 0.5 wet 0.5-1.0 wet 3.0-3.5 
2 dry dry wet 0.5-1.0 wet 3.0-3.5 
5 dry dry wet < 0.5 wet 2.5-3.0 
10 dry dry dry dry wet 2.0-2.5 
20 dry dry dry dry wet 1.5-2.0 
25 dry dry dry dry wet 1.5-2.0 
30 dry dry dry dry wet 1.5-2.0 
50 dry dry dry dry wet 1.0-1.5 
100 dry dry dry dry wet 0.5-1.0 
* All elevation in NAVD-88

A-22 
BELLE ISLE BRIDGE 
APPROX. CRITICAL 
ELEVATION (FT) 12.26 
2013 2030 2070 
EXCEEDANCE PROBABILITY 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH 
(FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
0.1 dry dry 10.80 -1.46 14.1 1.84 
0.2 dry dry 10.50 -1.76 14.0 1.74 
0.5 dry dry 10.20 -2.06 13.5 1.24 
1 dry dry 10.10 -2.16 12.8 0.54 
2 dry dry dry dry 12.5 0.24 
5 dry dry dry dry 12.2 -0.06 
10 dry dry dry dry 11.6 -0.66 
25 dry dry dry dry 10.8 -1.46 
30 dry dry dry dry 10.7 -1.56 
50 dry dry dry dry 10.4 -1.86 
100 dry dry dry dry dry dry 
LORING RD BOAT RAMP 
APPROX. CRITICAL 
ELEVATION (FT) 12.56 
2013 2030 2070 
EXCEEDANCE PROBABILITY 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH 
(FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
0.1 9.70 -2.86 10.5 -2.06 14.1 1.54 
0.2 9.60 -2.96 10.20 -2.36 14.0 1.44 
0.5 9.00 -3.56 10.10 -2.46 13.5 0.94 
1 8.30 -4.26 9.90 -2.66 12.8 0.24 
2 8.10 -4.46 9.70 -2.86 12.5 -0.06 
5 7.80 -4.76 9.20 -3.36 12.2 -0.36 
10 7.20 -5.36 8.90 -3.66 11.6 -0.96 
20 7.10 -5.46 8.30 -4.26 11.0 -1.56 
25 7.00 -5.56 8.20 -4.36 10.8 -1.76 
30 6.90 -5.66 8.10 -4.46 10.7 -1.86 
50 6.70 -5.86 7.90 -4.66 10.4 -2.16 
100 6.28 -6.28 7.28 -5.28 9.8 -2.76 
* All elevation in NAVD-88

A-23 
MAIN STREET 
APPROX. CRITICAL 
ELEVATION (FT) 9.00 
2013 2030 2070 
EXCEEDANCE PROBABILITY 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
0.1 9.8 0.8 10.8 1.8 14.1 5.1 
0.2 9.7 0.7 10.5 1.5 14.0 5.0 
0.5 9.1 0.1 10.2 1.2 13.5 4.5 
1 8.8 -0.2 10.1 1.1 12.8 3.8 
2 8.30 -0.7 9.9 0.9 12.5 3.5 
5 dry dry 9.10 0.1 12.2 3.2 
10 dry dry 8.80 -0.2 11.6 2.6 
20 dry dry 8.50 -0.5 11.0 2.0 
25 dry dry 8.10 -0.9 10.8 1.8 
30 dry dry dry dry 10.7 1.7 
50 dry dry dry dry 10.4 1.4 
100 dry dry dry dry 9.80 0.8 
PICO SEWER PUMP STATION 
APPROX. CRITICAL 
ELEVATION (FT) 8.50 
2013 2030 2070 
EXCEEDANCE PROBABILITY 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
WATER 
SURFACE 
ELEVATION 
(FT) 
WATER 
DEPTH (FT) 
WATER 
SURFACE 
ELEVATION 
(FT)

The text goes on. The rest is in the file.