HomeMy Public PortalAboutWatertown_MA_Draft_Plan_Update 2019-01-07 h
TOWN OF WATERTOWN
DRAFT HAZARD MITIGATION PLAN
2019 UPDATE
k - WATERG N- MBA
-
.a,
L I 'raw
. � t
ti r :.
IKMAPC 50YLARS
METROPOLITAN AREA PLANNING COUNCIL
SMART 6RIOWTH AND RE610NAL COLIA90RAlrON
DRAFT
January 7, 2019
[This page intentionally left blank]
ACKNOWLEDGEMENTS
This plan was prepared for the Town of Watertown by the Metropolitan Area Planning Council (MAPC)
under the direction of the Massachusetts Emergency Management Agency (MEMA) and the Massachusetts
Department of Conservation and Recreation (DCR). The plan was funded by the Federal Emergency
Management Agency's (FEMA) Pre-Disaster Mitigation (PDM) Grant Program.
MAPC Officers
President, Keith Bergman, Town of Littleton
Vice President, Erin Wortman, Town of Stoneham
Secretary, Sandra Hackman, Town of Bedford
Treasurer, Taber Keally, Town of Milton
Executive Director, Marc Draisen, MAPC
Credits
Project Manager: Martin Pillsbury
Mapping/GIS Services: Caitlin Spence,
Massachusetts Emergency Management Agency
Director: Kurt Schwartz
Department of Conservation and Recreation
Commissioner: Leo Roy
Watertown Local Hazard Mitigation Planning Team
Robert Quinn Fire Department
Gerald Mee Public Works Department
Matthew Shuman Public Works Department
Steven Magoon Community Development and Planning
CITY OF WATERTOWN- DRAFT HAZARD MITIGATION PLAN- 2019 UPDATE
[This page intentionally left blank]
MAP ,_. CITY OF WATERTOWN- DRAFT HAZARD MITIGATION PLAN-2019 UPDATE II
TABLE OF CONTENTS MEMN'
ACKNOWLEDGEMENTS & CREDITS..................................................................I
LIST OF TABLES AND FIGURES ..................................................................... IV
SECTION 1 : EXECUTIVE SUMMARY ................................................................1
SECTION 2: INTRODUCTION...........................................................................5
SECTION 3: PLANNING PROCESS & PUBLIC PARTICIPATION .....................1 1
SECTION 4: RISK ASSESSMENT.....................................................................17
SECTION 5: HAZARD MITIGATION GOALS ..................................................65
SECTION 6: EXISTING MITIGATION MEASURES ...........................................67
SECTON 7: STAOFTUS MITIGATION MEASURES FROM 2012 PLAN.............75
SECTION 8: HAZARD MITIGATION STRATEGY.............................................79
SECTION 9: PLAN ADOPTION AND MAINTENANCE............................89
SECTION 10: LIST OF REFERENCES..................................................91
APPENDIX A: LOCAL HAZARD MITIGATION TEAM MEETINGS................93
APPENDIX B: HAZARD MAPPING...................................................97
APPENDIX C: PUBLIC MEETINGS...................................................107
APPENDIX D: DOCUMENTATION OF PLAN ADOPTION.......................1 13
APPENDIX E: DOCUMENTATION OF PLAN APPROVAL.......................1 15
CITY OF WATERTOWN—HAZARD MITIGATION PLAN—2019 UPDATE iii of 12A
LIST OF TABLES & FIGURES
TABLES
Table 1: Plan Review and Update Process...................................................................................................................3
Table 2: Previous Federal/State Disaster Declarations.............................................................................................5
Table 3: FEMA-Funded Mitigation Projects...................................................................................................................7
Table 4: Watertown Characteristics..............................................................................................................................8
Table5: Watertown Public Meetings......................................................................................................................... 13
Table 6: Hazard Risk Summary.........................................................................................17
Table 7: Middlesex County Flood Events, 1996 to 2017....................................................................................... 19
Table 8: Locally Identified Areas of Flooding ..........................................................................................................23
Table 9: Inventory of Dams in and Upstream of Watertown.................................................................................26
Table 10: Hurricane Records for Massachusetts, 1938 to 2012...........................................................................26
Table1 1: Enhanced Fujita Scale..................................................................................................................................28
Table 1 2: Tornado Records for Middlesex County..................................................................................................28
Table 1 3: Nor'easter Events for Massachusetts, 1978 to 2015............................................................................29
Table 14: Middlesex County Thunderstorm Events, 2006 to 2017......................................................................30
Table15: NESIS Categories.........................................................................................................................................33
Table 1 6: Severe Winter Storm Records for Massachusetts..................................................................................34
Table 17: Heavy Snow Events and Impacts in Middlesex County, 2000 to 2017............................................34
Table1 8: Hail Size Comparisons ................................................................................................................................36
Table 19: Middlesex County Ice Storm Events, 2000-2017..................................................................................36
Table20: Richter Scale and Effects............................................................................................................................38
Table 21: Historical Earthquakes in Massachusetts or Surrounding Area............................................................38
Table 22: Landslide Volume and Velocity.................................................................................................................41
Table 23: Middlesex County Extreme Cold and Wind Chill Occurrences...........................................................44
Table 24: Middlesex County Extreme Heat Occurrences.......................................................................................45
Table 25: Chronology of Major Droughts in Massachusetts...................................................................................47
Table 26: Town of Watertown, MA 2005 Land Use...............................................................................................52
Table 27: Summary of Watertown Developments, 2008-2017...........................................................................54
Table 28: Future Development Sites in Hazard Areas............................................................................................55
Table 29: Critical Facilities and Relationship to Hazard Areas.............................................................................57
Table 30: Estimated Damages from Hurricanes.......................................................................................................61
Table 31: Estimated Damages from Earthquakes....................................................................................................62
Table 32: Estimated Damages from Flooding...........................................................................................................63
Table 33: Existing Hazard Mitigation Measures in Watertown............................................................................71
Table 34: Status of Mitigation Measures from the 2012 Plan..............................................................................75
Table 35: Prioritization of Mitigation Measures.......................................................................................................82
Table 36: Recommended Hazard Mitigation Measures..........................................................................................84
CITY OF WATERTOWN —HAZARD MITIGATION PLAN—2019 UPDATE iv of 124
FIGURES
Figure 1: Six-Step Planning Process............................................................................................................................ 1 1
Figure 2: USGS Flow Gage Data for the Assabet River, March 2010................................................................21
Figure 3: Aerial View of the Watertown Dam..........................................................................................................25
Figure 4: State of Massachusetts Earthquake Probability Map ............................................................................40
Figure 5: Massachusetts Wildfires, 2001 to 2009...................................................................................................43
Figure 6: Wind Chill Temperature Index and Frostbit Risk.....................................................................................44
Figure7: Heat Index Chart...........................................................................................................................................45
Figure 8: Statewide Drought Levels using SPI Thresholds, 1850 to 2012...........................................................47
Figure 9: Massachusetts Drought Status, December 2016............................................................49
Figure 10: Changes in Frequency of Extreme Downpours, 1948 — 201 1 .........................................51
Figure 1 1: Extreme Heat Scenarios.....................................................................................51
Figure 1 2: Watertown Magnitude 7 Earthquake Losses by Occupancy Type...................................62
Figure 13: Watertown 500-Year Flood Losses by Occupancy Type..............................................63
CITY OF WATERTOWN—HAZARD MITIGATION PLAN—2019 UPDATE v of 124
[This page intentionally left blank]
�j CITY OF WATERTOWN—HAZARD MITIGATION PLAN—2019 UPDATE vi of 124
SECTION 1 : EXECUTIVE SUMMARY
Hazard Mitigation planning is a proactive effort to identify actions that can be taken to reduce the
dangers to life and property from natural hazard events. In the communities of the Boston region of
Massachusetts, hazard mitigation planning tends to focus most on flooding, the most likely natural hazard
to impact these communities. The Federal Disaster Mitigation Act of 2000 requires all municipalities that
wish to be eligible to receive FEMA funding for hazard mitigation grants, to adopt a local multi-hazard
mitigation plan and update this plan in five year intervals.
PLANNING PROCESS
Planning for the Hazard Mitigation Plan update was led by the Watertown Local Hazard Mitigation
Planning Team, composed of staff from a number of different Town Departments. This team met on March
6, 2018, August 10, 2018, and December 18, 2018 and discussed where the impacts of natural hazards
most affect the town, goals for addressing these impacts, updates to the Town's existing mitigation
measures, and new or revised hazard mitigation measures that would benefit the town.
Public participation in this planning process is important for improving awareness of the potential impacts
of natural hazards and to build support for the actions the Town takes to mitigate them. The Town's Local
Hazard Mitigation Planning Team held two public meetings, the first hosted by the Joint Committees on
Public Works and Public Safety on December 4, 2018 and the second hosted by the Town Council on
January 8 2019, and the draft plan update was posted on the Town's website for public review. Key town
stakeholders and neighboring communities were notified of the public meeting and invited to review the
draft plan and submit comments.
RISK ASSESSMENT
The Watertown Hazard Mitigation Plan assesses the potential impacts to the Town from flooding, high
winds, winter storms, brush fire, geologic hazards, extreme temperatures, and drought. These are shown in
the map series in Appendix B.
The Watertown Local Hazard Mitigation Planning Team identified 82 Critical Facilities. These are also
shown on the map series and listed in Table 29, identifying which facilities are located within the mapped
hazard zones.
A HAZUS-MH analysis provided estimates of property damages from Hurricanes of 100-year and 500-
year frequency ($24.8 million to $1 12.5 million) as well as earthquakes of magnitudes 5 and 7 ($891
million to $5.0 billion) and flood damage ranging from ($45.6 million to $69.1 million).
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
P�11 INTRODUCTION 1 of 124
HAZARD MITIGATION GOALS
The Watertown Local Multiple Hazard Community Planning Team reviewed and discussed the set of goals
for the Town of Watertown. The Team endorsed the eight goals included in the previous plan, and added
an additional goal relating to climate change. The following goals were endorsed by the team for the
Watertown Hazard Mitigation Plan 2018 Update:
1. Prevent and reduce the loss of life, injury, public health impacts and property damages resulting
from all major natural hazards.
2. Identify and seek funding for measures to mitigate or eliminate each known significant flood
hazard area.
3. Integrate hazard mitigation planning as an integral factor in all relevant municipal departments,
committees and boards.
4. Prevent and reduce the damage to public infrastructure resulting from all hazards.
5. Encourage the business community, major institutions and non-profits to work with the Town to
develop, review and implement the hazard mitigation plan.
6. Work with surrounding communities, state, regional and federal agencies to ensure regional
cooperation and solutions for hazards affecting multiple communities.
7. Ensure that future development meets federal, state and local standards for preventing and
reducing the impacts of natural hazards.
8. Take maximum advantage of resources from FEMA and MEMA to educate Town staff and the
public about hazard mitigation.
9. Consider the impacts of climate change and incorporate climate sustainability and resiliency into
hazard mitigation and other Town plans and policies.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
I'�1�4 INTRODUCTION 2 of 124
HAZARD MITIGATION STRATEGY
The Watertown Local Hazard Mitigation Planning Team identified a number of mitigation measures that
would serve to reduce the Town's vulnerability to natural hazard events. Overall, the hazard mitigation
strategy recognizes that mitigating hazards for Watertown will be an ongoing process as our
understanding of natural hazards and the steps that can be taken to mitigate their damages changes over
time. Global climate change and a variety of other factors impact the Town's vulnerability and in the
future, and local officials will need to work together across municipal lines and with state and federal
agencies in order to understand and address these changes. The Hazard Mitigation Strategy will be
incorporated into the Town's other related plans and policies.
PLAN REVIEW & UPDATE PROCESS
The process for developing Watertown's Hazard Mitigation Plan 2019 Update is summarized in Table 1.
Table 1: Plan Review and Update Process
Section Reviews and Updates
The Local Hazard Mitigation Planning Team placed an emphasis on public
participation for the update of the Hazard Mitigation Plan, discussing strategies
Section 3: Public to enhance participation opportunities at the first local committee meeting.
Participation During plan development, the plan was discussed at two public meetings hosted
by the Watertown Board of Selectmen. The plan was also available on the
Town's website for public commentbbb.
MAPC gathered the most recently available hazard and land use data and met
Section 4: Risk with Town staff to identify changes in local hazard areas and development
Assessment trends. Town staff reviewed critical infrastructure with MAPC staff in order to
create an up-to-date list. MAPC also used the most recently available version of
HAZUS and assessed the potential impacts of flooding using the latest data.
Section 5: Goals The Hazard Mitigation Goals were reviewed and endorsed by the Watertown
Local Hazard Mitigation Planning Team.
Section b: Existing The list of existing mitigation measures was updated to reflect current mitigation
Mitigation Measures activities in the town.
Mitigation measures from the 2012 plan were reviewed and assessed as to
whether they were completed, in progress, or deferred. The Local Hazard
Sections 7 and 8: Mitigation Planning Team determined whether to carry forward measures into
Hazard Mitigation the 2019 Plan Update or modify or delete them. The Plan Updates hazard
Strategy mitigation strategy reflects both new measures and measures carried forward
from the 2012 plan. The Local Hazard Mitigation Team prioritized all of these
measures based on current conditions.
Section 9: Plan This section of the plan was updated with a new on-going plan implementation
Adoption & review and five year update process that will assist the Town in incorporating
Maintenance hazard mitigation issues into other Town planning and regulatory review
processes and better prepare the Town for the next comprehensive plan update.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
P�1�4 INTRODUCTION 3 of 124
As indicated in Table 34, Watertown made progress implementing mitigation measures identified in the
2012 Hazard Mitigation Plan. The town completed several mitigation measures include. Adoption of a
Stormwater Ordinance, installation of a fixed generator in Town Hall, initiation of a test program to assist
homeowners with installing pumps, increased capacity for sediment removal in drainage facilities,
acquisition of hand-held GPS units and upgrade of GIS equipment.
Several projects that were not completed will be continued into this plan update. These include installing
backup generators in several schools, implementing the Rutland Street project for pump installations,
increasing capacity for tree maintenance, coordinating dam management with state agencies, and
upgrading the emergency communications system for inter-operability between Fire, Police, and Public
Works. .
Moving forward into the next five year plan implementation period there will be many more opportunities
to incorporate hazard mitigation into the Town's decision making processes.
Though not formally done in the 2012 Plan, the Town will document any actions taken within this iteration
of the Hazard Mitigation Plan on challenges met and actions successfully adopted as part of the ongoing
plan maintenance to be conducted by the Watertown Hazard Mitigation Implementation Team, as
described in Section 9 Plan Adoption and Maintenance.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
I'�11 INTRODUCTION 4 of 124
SECTION 2 : INTRODUCTION
PLANNING REQUIREMENTS UNDER THE FEDERAL DISASTER MITIGATION ACT
The Federal Disaster Mitigation Act, passed in 2000, requires that after November 1, 2004, all
municipalities that wish to continue to be eligible to receive FEMA funding for hazard mitigation grants,
must adopt a local multi-hazard mitigation plan and update this plan in five year intervals. This planning
requirement does not affect disaster assistance funding.
Federal hazard mitigation planning and grant programs are administered by the Federal Emergency
Management Agency (FEMA) in collaboration with the states. These programs are administered in
Massachusetts by the Massachusetts Emergency Management Agency (MEMA) in partnership with the
Department of Conservation and Recreation (DCR).
Massachusetts has taken a regional approach and has encouraged the regional planning agencies to
apply for grants to prepare plans for groups of their member communities. The Metropolitan Area
Planning Council (MAPC) received a grant from the Federal Emergency Management Agency (FEMA)
under the Pre-Disaster Mitigation (PDM) Program, to assist the Town of Watertown to update its local
Hazard Mitigation Plan, which was first adopted in 2012.
WHAT IS A HAZARD MITIGATION PLAN?
Natural hazard mitigation planning is the process of determining how to systematically reduce or eliminate
the loss of life and property damage resulting from natural hazards such as floods, earthquakes, and
hurricanes. Hazard mitigation means to permanently reduce or alleviate the losses of life, injuries, and
property resulting from natural hazards through long-term strategies. These long-term strategies include
planning, policy changes, programs, projects, and other activities.
PREVIOUS FEDERAL/STATE DISASTERS
The Town of Watertown has experienced 20 natural hazards that triggered federal or state disaster
declarations since 1991. These are listed in Table 2 below. The majority of these events involved flooding,
while five were due to hurricanes or nor'easters, and four were due to severe winter weather.
Table 2: Previous Federal/State Disaster Declarations
Disaster Name (Date Type of Assistance Declared Areas
of Event)
FEMA Public Assistance Counties of Barnstable, Bristol, Dukes, Essex,
Project Grants Hampden, Middlesex, Plymouth, Nantucket,
Hurricane Bob Norfolk, Suffolk
(August 1991) Counties of Barnstable, Bristol, Dukes, Essex,
Hazard Mitigation Grant Hampden, Middlesex, Plymouth, Nantucket,
Program Norfolk, Suffolk (16 projects)
lK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
P APC INTRODUCTION 5 of 124
Disaster Name (Date Type of Assistance Declared Areas
of Event)
FEMA Public Assistance Counties of Barnstable, Bristol, Dukes, Essex,
Project Grants Middlesex, Plymouth, Nantucket, Norfolk
No-Name Storm FEMA Individual Counties of Barnstable, Bristol, Dukes, Essex,
(October 1991) Household Program Middlesex, Plymouth, Nantucket, Norfolk
Hazard Mitigation Grant Counties of Barnstable, Bristol, Dukes, Essex,
Program Middlesex, Plymouth, Nantucket, Norfolk,
Suffolk (10 projects)
March Blizzard FEMA Public Assistance All 14 Counties
(March 1993) Project Grants
January Blizzard FEMA Public Assistance All 14 Counties
(January 1996) Project Grants
May Windstorm State Public Assistance
Counties of Plymouth, Norfolk, Bristol
(May 1996) Project Grants
FEMA Public Assistance Counties of Essex, Middlesex, Norfolk,
Project Grants Plymouth, Suffolk
October Flood FEMA Individual Counties of Essex, Middlesex, Norfolk,
(October 1996) Household Program Plymouth, Suffolk
Hazard Mitigation Grant Counties of Essex, Middlesex, Norfolk,
Program Plymouth, Suffolk (36 projects)
1997 Community Development Counties of Essex, Middlesex, Norfolk,
Block Grant-HUD Plymouth, Suffolk
FEMA Individual Counties of Bristol, Essex, Middlesex, Norfolk,
Household Program Suffolk, Plymouth, Worcester
June Flood 1998
Hazard Mitigation Grant Counties of Bristol, Essex, Middlesex, Norfolk,
Program Suffolk, Plymouth, Worcester (19 projects)
1998 Community Development Counties of Bristol, Essex, Middlesex, Norfolk,
Block Grant-HUD Suffolk, Plymouth, Worcester
FEMA Individual Counties of Bristol, Essex, Middlesex, Norfolk,
Household Program Suffolk, Plymouth, Worcester
March Flood 2001
Hazard Mitigation Grant Counties of Bristol, Essex, Middlesex, Norfolk,
Program Suffolk, Plymouth, Worcester (16 projects)
February Snowstorm FEMA Public Assistance All 14 Counties
(Feb 17-18, 2003) Project Grants
January Blizzard FEMA Public Assistance
(January 22-23, Project Grants All 14 Counties
2005)
Hurricane Katrina FEMA Public Assistance
All 14 Counties
(August 29, 2005) Project Grants
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC INTRODUCTION 6 of 124
Disaster Name (Date Type of Assistance Declared Areas
of Event)
May Rainstorm/ Flood Hazard Mitigation Grant
Statewide
May 12-23, 2006 Program
April Nor'easter Hazard Mitigation Grant Statewide
April 15-27, 2007 Program
FEMA Public Assistance
FEMA Individuals and Bristol, Essex, Middlesex, Suffolk, Norfolk,
Flooding Households Program Plymouth, Worcester
March, 2010 SBA Loan
Hazard Mitigation Grant Statewide
Program
Tropical Storm Irene FEMA Public Assistance Statewide
August 27-28, 201 1
Hurricane Sandy FEMA Public Assistance Statewide
October 27-30, 2012
Severe snowstorm and FEMA Public Assistance;
Flooding February 8- Hazard Mitigation Grant Statewide
9, 201 3 Program
Blizzard of 2015 FEMA Public Assistance;
January 26-28, 2015 Hazard Mitigation Grant Statewide
Program
Winter Storm Riley
Hazard Mitigation Grant
and Flooding March Statewide
3-6, 2018 Program
Source: Database provided by MEMA
FEMA FUNDED MITIGATION PROJECTS
The Town of Watertown has not received funding from FEMA for mitigation projects, but MAPC received
funding to prepare the Town's first Hazard Mitigation Plan and the Town received a grant for this 2018
plan update. These grants are summarized in Table 3 below.
Table 3: FEMA-Funded Mitigation Plans
Grant Grantee/ Scope of Work Total Cost Federal Local
Project Title Funding Funding
MAPC/ Development of first
PDMC Hazard hazard mitigation plan
07-01 Mitigation (17 municipalities $217,000 $162,000 $54,000
Planning including Watertown)
Watertown/
PDM16- Hazard Update of first hazard
$20,000 $15,000 $5,000
Wat Mitigation mitigation plan
Planning
Source:MEMA Grants Database
JK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC INTRODUCTION 7 of 124
COMMUNITY PROFILE
Founded in 1630, Watertown was the first inland settlement in Massachusetts and initially encompassed
the present communities of Weston, Waltham and large sections of Lincoln, Belmont, and Cambridge, thus
becoming one of the largest American settlements of its time. Settled by Englishmen who had set sail on
the Arbella, and were led by Sir Richard Saltonstall, Watertown quickly grew to be an important center
for trade, commerce, and industry. Over the years this community has played an important role in
Massachusetts history, once serving as the temporary seat of government during the Revolutionary War.
Located along the banks of the Charles River, today Watertown is a dense community on the immediate
outskirts of Boston. With only 4.1 square miles and a population of 35,756 people, This diverse suburb
provides its residents with a close-knit community and prime access to economic, medical, and education
centers in the Boston metropolitan area.
Today Watertown is rich in ethnic diversity and culture, boasts a high level of citizen involvement and many
amenities such as shopping malls, swimming pools, country and tennis clubs, skating rinks, eleven fine parks,
and public transportation providing easy access to Boston and surrounding communities.
(Narrative supplied by the community and taken from the Community Profile on the website maintained by
the Department of Housing and Community Development and the Watertown Open Space and Recreation
Plan)
The Town is governed by a nine-member Town Council with a Town Manager acting as the Town's Chief
Administrative Officer. The town maintains a website at http://www.ci.watertown.ma.us/-
According to the US Census 2017 American Community Survey, the population was 35,756 people and
there were 16,046 housing units.
Table 4: Watertown Characteristics
Population = 35,756,
• 6.7% are under age 5
• 15.7% are under age 18
• 15.4% are over age 65
10% have a disability
• 28.9% speak English-less than very well
Number of Housing Units = 16,046
• 50% are renter-occupied housing units
• 42.6% of housing units were built before 1940
Sources: US Census, 2017 American Community Survey
Important characteristics of Watertown to keep in mind include:
• Watertown serves as a regional hub that draws people from nearby communities due to the retail
services and restaurants, particularly in Watertown Square and the former Arsenal site.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
P�11 INTRODUCTION 8 of 124
• Watertown's location on the Charles River provides important open space, some of which is owned by
the Massachusetts Department of Conservation and Recreation, which serves as a regional resource.
• Watertown is continuously growing and continues to face development, both residential and
commercial.
• Watertown on the Massachusetts Water Resources Authority for both drinking water and wastewater
services, providing the town with reliable infrastructure services.
JK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC INTRODUCTION 9 of 124
[This page intentionally left blank]
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
INTRODUCTION 10 of 124
IMP
MAPC employs a six step planning process based on FEMA's hazard mitigation planning guidance focusing
on local needs and priorities but maintaining a regional perspective matched to the scale and nature of
natural hazard events. Public participation is a central component of this process, providing critical
information about the local occurrence of hazards while also serving as a means to build a base of support
for hazard mitigation activities. MAPC supports participation by the general public and other plan
stakeholders through a Local Hazard Mitigation Planning Teams two public meetings hosted by the local
Hazard Mitigation Team, posting of the plan to the Town's website, and invitations sent to neighboring
communities, Town boards and commissions, and other local or regional entities to review the plan and
provide comment.
PLANNING PROCESS SUMMARY
The six-step planning process outlined below is based on the guidance provided by FEMA's Local Multi-
Hazard Mitigation Planning Guidance. Public participation is a central element of this process, which
attempts to focus on local problem areas and identify needed mitigation measures based on where gaps
occur in the existing mitigation efforts of the municipality. By working on municipal hazard mitigation plans
in groups of neighboring cities and towns, MAPC is able to identify regional opportunities for collaboration
and facilitate communication between communities. In plan updates, the process described below allows
staff to bring the most recent hazard information into the plan, including new hazard occurrence data,
changes to a municipality's existing mitigation measures, and progress made on actions identified in
previous plans.
Figure 1: Six-Step Planning Process
T
&lap the Hazards
Implement & Update Assess the Risks
the Plan � Potential Damages
PFTBLI INPUT
Plan Approval Review Existing
Adoption Mitigation
Develop lWitigation
Strategies
IC CITY OF WATERTOWN—HAZARD MITIGATION PLAN—2019 UPDATE
MAPC PLANNING PROCESS & PUBLIC PARTICIPATION 11 of 124
1. Map the Hazards —MAPC relies on data from a number of different federal, state, and local
sources in order to map the areas with the potential to experience natural hazards. This mapping
represents a multi-hazard assessment of the municipality and is used as a set of base maps for the
remainder of the planning process. A particularly important source of information is the knowledge
drawn from local municipal staff on where natural hazard impacts have occurred. These maps can
be found in Appendix B.
2. Assess the Risks & Potential Damages —Working with local staff, critical facilities, infrastructure,
vulnerable populations, and other features are mapped and contrasted with the hazard data from
the first step to identify those that might represent particular vulnerabilities to these hazards. Land
use data and development trends are also incorporated into this analysis. In addition, MAPC
develops estimates of the potential impacts of certain hazard events on the community. MAPC drew
on the following resources to complete the plan:
• Town of Watertown, Zoning Ordinance
• Town of Watertown, Stormwater Ordinance
• Town of Watertown, Wetlands Ordinance
• Town of Watertown Open Space and Recreation Plan, 2015
• FEMA, Local Mitigation Plan Review Guide, October 2011
• FEMA, Flood Insurance Rate Maps for Middlesex County, MA, 2010
• Massachusetts State Hazard Mitigation Plan
• Metropolitan Area Planning Council, GIS Lab, Regional Plans and Data.
• New England Seismic Network, Boston College Weston Observatory
• NOAA National Center for Environmental Information
• Northeast States Emergency Consortium
• USGS, National Water Information System
• US Census, 2010 and American Community Survey, 2017
3. Review Existing Mitigation — Municipalities in the Boston Metropolitan Region have an active
history in hazard mitigation as most have adopted flood plain zoning districts, wetlands protection
programs, and other measures as well as enforcing the State building code, which has strong
provisions related to hazard resistant building requirements. All current municipal mitigation
measures must be documented.
4. Develop Mitigation Strategies — MAPC works with the local municipal staff to identify new
mitigation measures, utilizing information gathered from the hazard identification, vulnerability
assessments, and the community's existing mitigation efforts to determine where additional work is
necessary to reduce the potential damages from hazard events. Additional information on the
development of hazard mitigation strategies can be found in Section 7.
5. Plan Approval & Adoption — Once a final draft of the plan is complete it is sent to MEMA for the
state level review and, following that, to FEMA for approval. Typically, once FEMA has approved
the plan the agency issues a conditional approval (Approval Pending Adoption), with the condition
being adoption of the plan by the municipality. More information on plan adoption can be found in
Section 9 and documentation of plan adoption can be found in Appendix D.
6. Implement & Update the Plan — Implementation is the final and most important part of any
planning process. Hazard Mitigation Plans must also be updated on a five year basis making
JK CITY OF WATERTOWN—HAZARD MITIGATION PLAN—2019 UPDATE
MAPC PLANNING PROCESS & PUBLIC PARTICIPATION 12 of 124
preparation for the next plan update an important on-going activity. Section 9 includes more
detailed information on plan implementation.
2012 PLAN IMPLEMENTATION & MAINTENANCE
The 2012 Town of Watertown Hazard Mitigation Plan contained a risk assessment of identified hazards
for the town and mitigation measures to address the risk and vulnerability from these hazards. Since
approval of the plan by FEMA and local adoption, progress has been made on implementation of the
measures. The Town has advanced a number of projects, including adoption of a stormwater ordinance,
stormwater drainage projects, purchase of mobile generators, and upgraded GIS.
THE LOCAL MULTIPLE HAZARD COMMUNITY PLANNING TEAM
MAPC worked with the local community representatives to organize a Local Hazard Mitigation Planning
Team for Watertown. MAPC briefed the local representatives as to the desired composition of that team
as well as the need for public participation in the local planning process.
The Local Hazard Mitigation Planning Team is central to the planning process as it is the primary body
tasked with developing a mitigation strategy for the community. The local team was tasked with working
with MAPC to set plan goals, provide information on the hazards that impact the town, existing mitigation
measures, and helping to develop new mitigation measures for this plan update. The Local Hazard
Mitigation Planning Team membership are listed in Table 5 below.
able 5: Watertown Local Hazard Mitigation Team
Robert Quinn Fire Department
Gerald Mee Public Works Department
Matthew Shuman Public Works Department
Steven Magoon Community Development and Planning
The Watertown Planning Board and the Watertown Conservation Commission are the primary entities
responsible for regulating development in town. Feedback from the Planning Board and the Conservation
Commission was assured through the participation of the Director of Community Development and Planning,
which includes staff to both the Planning Board and Conservation Commisson. In addition, MAPC, the
State-designated regional planning authority for Watertown, works with all agencies that regulate
development in the region, including the listed municipal entities and state agencies, such as the MassDOT
(MassHighway and MBTA), the Department of Conservation and Recreation (open space and dams), and
the Massachusetts Water Resources Authority (water supply and wastewater).
The Local Hazard Mitigation Planning Team met on the following dates: March 6, 2018, August 10, 201 8;
and December 18, 2018. The purpose of the meetings was to introduce the Hazard Mitigation planning
program, review and update hazard mitigation goals, and to gather information on local hazard
mitigation issues and sites or areas related to these. Later meetings focused on verifying information
gathered by MAPC staff and discussion of existing mitigation practices, the status of mitigation measures
identified in the 2012 hazard mitigation plan, and potential new or revised mitigation measures. The
agendas for these meetings are included in Appendix A.
CITY OF WATERTOWN—HAZARD MITIGATION PLAN—2019 UPDATE
MAPC PLANNING PROCESS & PUBLIC PARTICIPATION 13 of 124
PUBLIC MEETINGS
Public participation in the hazard mitigation planning process is important, both for plan development and
for later implementation of the plan. Residents, business owners, and other community members are an
excellent source for information on the historic and potential impacts of natural hazard events and
particular vulnerabilities the community may face from these hazards. Their participation in this planning
process also builds understanding of the concept of hazard mitigation, potentially creating support for
mitigation actions taken in the future to implement the plan. To gather this information and educate
residents on hazard mitigation, the Town hosted two public meetings, one during the planning process and
one after a complete draft plan is available for review.
Natural hazard mitigation plans unfortunately rarely attract much public involvement in the Boston region,
unless there has been a recent hazard event. One of the best strategies for overcoming this challenge is to
include discussion of the hazard mitigation plan on the agenda of an existing board or commission. With
this strategy, the meeting receives widespread advertising and a guaranteed audience of the board or
commission members plus those members of the public who attend the meeting. These board and
commission members represent an engaged audience that is informed and up to date on many of the issues
that relate to hazard mitigation planning in the locality and will likely be involved in plan implementation,
making them an important audience with which to build support for hazard mitigation measures. In
addition, these meetings frequently receive press coverage, expanding the audience that has the
opportunity to hear the presentation and provide comment.
The public had an opportunity to provide input to the Watertown hazard mitigation planning process
during a meeting of the Joint Committees on Public Works and Public Safety on December 3, 2018 held in
at Watertown Town Hall. The draft plan update was presented at a Town Council meeting on January 8,
2019 at Watertown Town Hall. Both meetings were publicized in accordance with the Massachusetts
Public Meeting Law (see public meeting notices in Appendix C). Both meetings were broadcast on
Watertown Local Access Cable Television.
LOCAL STAKEHOLDER INVOLVEMENT
The local Hazard Mitigation Planning Team was encouraged to reach out to local stakeholders that might
have an interest in the Hazard Mitigation Plan including neighboring communities, agencies, businesses,
nonprofits, and other interested parties. Notice was sent to the following organizations and neighboring
municipalities inviting them to review the Hazard Mitigation Plan and submit comments to the Town:
• Armenian Museum of America • Watertown Health Center
• Athena Health • Watertown Mall Merchants
• Historical Society of Watertown • Town of Belmont
• Oakley Country Club • City of Waltham
• Perkins School for the Blind • City of Cambridge
• Rotary Club of Watertown • City of Boston
• Watertown Community Foundation • City of h
• Watertown Early Childhood Services
• Watertown Free Public Library
JK CITY OF WATERTOWN—HAZARD MITIGATION PLAN—2019 UPDATE
MAIPC PLANNING PROCESS & PUBLIC PARTICIPATION 14 of 124
The draft Watertown Hazard Mitigation Plan 2019 Update was posted on the Town's website for the
second public meeting. Members of the public could access the draft document and submit comments or
questions to the Town.
CONTINUING PUBLIC PARTICIPATION
Following the adoption of the plan update, the planning team will continue to provide residents, businesses,
and other stakeholders the opportunity to learn about the hazard mitigation planning process and to
contribute information that will update the town's understanding of local hazards. As updates and a review
of the plan are conducted by the Hazard Mitigation Implementation Team, these will be placed on the
Town's web site, and any meetings of the Hazard Mitigation Implementation Team will be publicly noticed
in accordance with town and state open meeting laws.
PLANNING TIMELINE
March 3, 2018 Meeting of the Watertown Local Hazard Mitigation Planning Team
August 10, 2018 Meeting of the Watertown Local Hazard Mitigation Planning Team
December 4, 2018 First Public Meeting with Joint Committees on Public Works and Public Safety
December 18, 2018 Meeting of the Watertown Local Hazard Mitigation Planning Team
January 8, 2019 Second Public Meeting with Watertown Town Council
TBD Draft Plan Update submitted to MEMA
1 CITY OF WATERTOWN—HAZARD MITIGATION PLAN—2019 UPDATE
MAIPC PLANNING PROCESS & PUBLIC PARTICIPATION 15 of 124
[This page intentionally left blank]
CITY OF WATERTOWN —HAZARD MITIGATION PLAN—201 9 UPDATE
P'1 PLANNING PROCESS & PUBLIC PARTICIPATION 16 of 124
SECTION 4: RISK ASSESSMENT
The risk assessment analyzes the potential natural hazards that could occur within the Town of Watertown
as well as the relationship between those hazards and current land uses, potential future development, and
critical infrastructure. This section also includes a vulnerability assessment that estimates the potential
damages that could result from certain large scale natural hazard events.
In order to update Watertown's risk assessment, MAPC gathered the most recently available hazard and
land use data and met with Town staff to identify changes in local hazard areas and development trends.
MAPC also used FEMA's damage estimation software, HAZUS.
OVERVIEW OF HAZARDS AND IMPACTS
The Massachusetts Hazard Mitigation Plan provides an in-depth overview of natural hazards in
Massachusetts. Previous state and federal disaster declarations since 1991 are summarized in Table 2.
Table 6 below summarizes the hazard risks for Watertown. This evaluation takes into account the
frequency of the hazard, historical records, and variations in land use. This analysis is based on the
vulnerability assessment in the Massachusetts State Hazard Mitigation Plan. The statewide assessment was
modified to reflect local conditions in Watertown using the definitions for hazard frequency and severity
listed below. Based on this, the Town set an overall priority for each hazard.
Table 6: Hazard Risks Summary
Hazard Frequency Severity
Massachusetts Watertown Massachusetts Watertown
Flooding High Medium Serious to Serious
extensive
Dam failures Low Low Extensive Extensive
Coastal Hazards High N/A Serious N/A
Tsumani Very Low N/A Extensive N/A
Hurricane/Tropical Storm Medium Medium Serious Serious
Tornadoes Medium Low Serious Minor
Thunderstorms High High Minor Minor
Nor'easter High High Minor Minor
Winter-Blizzard/Snow High High Minor Minor
Winter-Ice Storms Medium Medium Minor Minor
Winter Ice Jams Low N/A Serous N/A
Earthquakes Very Low Very Low Serious Serious
Landslides Low Low Minor Minor
Brush fires Medium Low Minor Minor
Major Urban Fires Low N/A Minor N?A
Extreme Temperatures Medium Medium Minor Minor
Drought Low Low Minor Minor
Source:Massachusetts State Hazard Mitigation Plan, 2013, modified for Watertown
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IBC RISK ASSESSMENT 17 of 124
Definitions Used in the Commonwealth of Massachusetts State Hazard Mitigation Plan
Frequencx
• Very low frequency: events that occur less frequently than once in 100 years (less than 1% per year).
• Low frequency: events that occur from once in 50 years to once in 100 years (1%to 2% per year).
• Medium frequency: events that occur from once in 5 years to once in 50 years (2%to 20% per year).
• High frequency: events that occur more frequently than once in 5 years (Greater than 20% per year).
Severity
• Minor: Limited and scattered property damage; limited damage to public infrastructure and essential
services not interrupted; limited injuries or fatalities.
• Serious: Scattered major property damage; some minor infrastructure damage; essential services are
briefly interrupted; some injuries and/or fatalities.
• Extensive: Widespread major property damage; major public infrastructure damage (up to several
days for repairs); essential services are interrupted from several hours to several days; many injuries
and/or fatalities.
• Catastrophic: Property and public infrastructure destroyed; essential services stopped; numerous
injuries and fatalities.
It should be noted that several of the hazards listed in the Massachusetts State Hazard Mitigation plan are
not applicable to the Town of Watertown. Due to its inland location away from the coast, coastal hazards
including Tsunamis and Storm Surge are not applicable to Watertown. Due to the low incidence of wildfires
in proximity to developed areas in Watertown, Major Urban Fires are also not applicable to this town. In
addition, ice jams are not a hazard for the town. The US Army Corps Ice Jam Database shows no record of
ice jams in Watertown.
FLOOD-RELATED HAZARDS
Flooding was the most prevalent serious natural hazard identified by local officials in Watertown. Flooding
is generally caused by hurricanes, nor'easters, severe rainstorms, and thunderstorms. Global climate
change has the potential to exacerbate these issues over time with the potential for changing rainfall
patterns leading to heavier storms.
REGIONALLY SIGNIFICANT FLOODS
There have been a number of major floods that have affected the Metro Boston region over the last sixty
years. Significant flood events that have impacted Watertown include:
August 1954
March 1968
January 1979
April 1987
October 1996
June 1998
March 2001
April 2004
May 2006
April 2007
March 2010
1 CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 18 of 124
Local data for previous flooding occurrences are not collected by the Town of Watertown. The best
available local data is for Middlesex County through the National Environmental Information Center (see
Table 7). Middlesex County, which includes the Town of Watertown, experienced 60 flood events from
1996 —2017. No deaths or injuries were reported and the total reported property damage in the county
was $41.9 million dollars. Of that total, $35.2 million is attributed to the two major events of March 2010.
Table 7: Middlesex County Flood Events, 1996 to 2018
Date Deaths Injuries Property Damage
1/29/1996 0 0 0
4/17/1996 0 0 0
9/18/1996 0 0 0
10/21/1996 0 0 0
10/22/1996 0 0 0
3/10/1998 0 0 0
3/11/1998 0 0 0
5/12/1998 0 0 0
6/14/1998 0 0 0
6/15/1998 0 0 0
6/17/1998 0 0 0
4/22/2000 0 0 0
4/23/2000 0 0 0
3/22/2001 0 0 0
3/23/2001 0 0 0
3/31/2001 0 0 0
4/1/2001 0 0 0
4/2/2004 0 0 0
4/15/2004 0 0 0
3/29/2005 0 0 0
10/15/2005 0 0 100,000
10/15/2005 0 0 100,000
10/15/2005 0 0 125,000
5/13/2006 0 0 5,000,000
7/1 1/2006 0 0 2,000
10/28/2006 0 0 5,000
4/16/2007 0 0 25,000
2/13/2008 0 0 0
5/27/2008 0 0 3,000
6/24/2008 0 0 10,000
6/29/2008 0 0 5,000
8/10/2008 0 0 15,000
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
APC RISK ASSESSMENT 19 of 124
Date Deaths Injuries Property Damage
8/10/2008 0 0 40,000
9/6/2008 0 0 15,000
12/12/2008 0 0 20,000
3/14/2010 0 0 26,430,000
3/29/2010 0 0 8,810,000
4/l/2010 0 0 0
8/28/201 1 0 0 5,000
10/14/2011 0 0 0
6/8/2012 0 0 0
6/23/2012 0 0 15,000
7/18/2012 0 0 5,000
10/29/2012 0 0 0
6/7/2013 0 0 0
7/l/2013 0 0 0
7/23/2013 0 0 0
9/l/2013 0 0 10,000
3/30/201A 0 0 35,000
7/27/201A 0 0 0
8/31/201A 0 0 0
10/22/2014 0 0 20,000
10/23/2014 0 0 0
12/9/2014 0 0 5,000
12/9/2014 0 0 30,000
5/31/2015 0 0 0
8/4/2015 0 0 0
8/15/2015 0 0 50,000
8/15/2015 0 0 75,000
9/30/2015 0 0 0
4/6/2017 0 0 0
6/27/2017 0 0 1,000
7/12/2017 0 0 1,000,000
7/18/17 0 0 0
8/2/2017 0 0 5,000
10/25/17 0 0 0
10/30/2017 0 0 0
1/12/2018 0 0 0
1/13/2018 0 0 0
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
RISK ASSESSMENT 20 of 124
Date Deaths Injuries Property Damage
A/16/2018 0 0 0
6/25/2018 0 0 15,000
Source: NOAA, National Environmental Information Center
The most severe flooding since the previous plan occurred during March 2010, when a total of 14.83
inches of rainfall accumulation was recorded by the National Weather Service (NWS). The weather
pattern that consisted of early springtime prevailing westerly winds that moved three successive storms,
combined with tropical moisture from the Gulf of Mexico, across New England. Torrential rainfall caused
March 2010 to be the wettest month on record.
One indication of the extent of flooding is the gage height at the nearest USGS streamflow gauging
station, which is on the Charles River in nearby Waltham. The USGS gage height, shown in Figure 2,
reached 7.5 feet on March 16, 2010 and over 6 feet on March 31, 2010. Average gage height in April
is about 4 feet.
Figure 2 USGS Flow Gage Data for Charles River, March 2010
USGS 01104500 CHARLES RIVER AT WALTHAM, MR
8.0
7.0
4J
6.0
S
5.0
.P�
L
4.0
+4
r7
3.0
2.0
Map Nap liar liar Apr Rpr
06 13 20 27 03 10
2010 2010 2010 2010 2010 2010
— Gage height Measured gage height
Period of approved data
Graph courtesy of the U.S. Geological Survey
Source: United States Geological Survey
JK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
PC RISK ASSESSMENT 21 of 12A
OVERVIEW OF TOWN-WIDE FLOODING
The Charles River is the predominant source of potential flood waters in Watertown. Flood zones line the
riverbanks, though they are generally constricted to the area immediately adjacent to the waterway. Most
actual flooding occurs upstream of the Watertown Dam. Groundwater sourced flooding of basements is
also relatively common across many different parts of the Town.
Information on flood hazard areas was taken from two sources. The first was the National Flood Insurance
Rate Maps. The FIRM flood zones are shown on Map 3 in Appendix B. The second was the Watertown
Hazard Mitigation Team. The locally identified areas of flooding described below were identified by
Town staff as areas where flooding occurs outside of the FIRM flood zones.
POTENTIAL FLOOD HAZARD AREAS
Information on potential flood hazard areas was taken from two sources. The first was the National Flood
Insurance Rate Maps. The FIRM flood zones are shown on Map 3 in Appendix B and their definitions are
listed below. Most of the FIRM flood zones in Watertown are located along the Charles River.
Flood Insurance Rate Map Zone Definitions
Zone A (1% annual chance): Zone A is the flood insurance rate zone that corresponds to the 100-year
floodplains that are determined in the Flood Insurance Study (FIS) by approximate methods. Because
detailed hydraulic analyses are not performed for such areas, no BFEs (base flood elevations) or depths
are shown within this zone. Mandatory flood insurance purchase requirements apply.
Zone AE and Al-A30 (1% annual chance): Zones AE and Al-A30 are the flood insurance rate zones that
correspond to the 100-year floodplains that are determined in the FIS by detailed methods. In most
instances, BFEs derived from the detailed hydraulic analyses are shown at selected intervals within this
zone. Mandatory flood insurance purchase requirements apply.
Zone X (0.2% annual chance): Zone X500 is the flood insurance rate zone that corresponds to the 500-
year floodplains that are determined in the Flood Insurance Study (FIS) by approximate methods. Because
detailed hydraulic analyses are not performed for such areas, no BFEs (base flood elevations) or depths
are shown within this zone.
LOCALLY IDENTIFIED AREAS OF FLOODING
In addition to the FIRM flood zones, information on other areas subject to flooding was provided by the
Watertown Local Hazard Mitigation Team. These "Locally Identified Areas of Flooding" are shown in
Table 8. These areas do not necessarily coincide with the flood zones from the FIRM maps. Some may be
areas that flood due to inadequate drainage systems or other local conditions rather than location within a
flood zone. The numbers in Table 8 correspond to the numbers on Map 8, "Local Hazard Areas."
JK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IBC RISK ASSESSMENT 22 of 124
Table 8: Locally Identified Areas of Flooding
Map ID Name Description
1 Charles River During severe storms flooding can occur directly along the shore on
this stretch of the Charles River, above the dam.
Cunniff Elementary
2 Basement flooding from groundwater.
School
Watertown High
3 Basement flooding from groundwater.
School
New Police
4 Basement flooding from groundwater.
Headquarters
7 Rutland Street Basement flooding of homes from groundwater.
Arlington Street and
8 Flooding was caused after a series of three storms
Keith Street
REPETITIVE LOSS STRUCTURES
There are no repetitive loss structures in Watertown. As defined by the Community Rating System (CRS) of
the National Flood Insurance Program (NFIP), a repetitive loss property is any property which the NFIP has
paid two or more flood claims of $1,000 or more in any given 10-year period since 1978. For more
information on repetitive losses see httD://www.fema.aov/business/nfiD/reDIDs.shtm.
Potential flooding damages to Watertown have been estimated using HAZUS-MH. Total losses are
estimated at $45.6 million for a 100-year flood event and $69.1 million for a 500-year flood event.
Other potential impacts are detailed in Table 32.
Based on the record of previous occurrences flooding events in Watertown are a medium frequency event
as defined by the Massachusetts State Hazard Mitigation Plan. This hazard may occur from once in 5
years to once in 50 years (2% to 20% per year) in Watertown.
DAMS AND DAM FAILURE
Dam failure can arise from two types of situations. Dams can fail because of structural problems
independent of any storm event. Dam failure can follow an earthquake by causing structural damage.
Dams can fail structurally because of flooding arising from a storm or they can overspill due to flooding.
In the event of a dam failure, the energy of the water stored behind even a small dam can cause loss of
life and property damage if there are people or buildings downstream. The number of fatalities from a
dam failure depends on the amount of warning provided to the population and the number of people in
the area in the path of the dam's floodwaters. An issue for dams in Massachusetts is that many were built
in the 19T" century without the benefits of modern engineering or construction oversight.
Dam failure is a highly infrequent occurrence but a severe incident could result in loss of lives and
significant property damage. According to the Association of State Dam Safety Officials, three dams have
failed in Massachusetts since 1984, one of which resulted in a death. There has not been a dam failure
incident in Watertown.
jK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 23 of 124
According to data provided by the Massachusetts Department of Conservation and Recreation (DCR) and
the town, there is one dam located in Watertown, the Watertown Dam on the Charles River, owned by the
MA Department of Conservation and Recreation (see Figure 3). The Town coordinates with DCR at this dam
and others up and downstream on the Charles River to maintain an appropriate level of flow during storm
events to manage flooding to the extent possible.
In addition to the Watertown Dam, there are also several upstream dams on tributaries of the Charles that
could have an impact on Watertown should they fail. These include two dams owned by the City of
Cambridge Water Department in Weston and Waltham, the Norumbega Reservoir Dams, Schenck's Pond
Dam, and Weston Reservoir Dam in Weston, operated by the Massachusetts Water Resources Authority.
The Watertown Dam and upstream dams are summarized in Table 9 according to river or stream,
ownership, and hazard potential. DCR defines dam hazard potential classifications as follows:
DCR Dam Hazard Classification
High: Dams located where failure or mis-operation will likely cause loss of life and serious damage to
homes(s), industrial or commercial facilities, important public utilities, main highways(s) or railroad(s).
Significant: Dams located where failure or mis-operation may cause loss of life and damage home(s),
industrial or commercial facilities, secondary highway(s) or railroad(s)
Low: Dams located where failure or mis-operation may cause minimal property damage to others. Loss of
life is not expected.
Table 9 Inventory of Dams in and Upstream of Watertown
Dam Name River/Stream Owner/Operator Owner Type Hazard Potential
Classification
Cambridge Reservoir Hobbs Brok City of Cambridge Municipal Significant Hazard
Norumbega Dam#1 Seaverns Brook DCR/MWRA State High Hazard
Norumbega Dam#2 Seaverns Brook DCR/MWRA State Significant Hazard
Norumbega Dam#3 Seaverns Brook DCR/MWRA State Significant Hazard
Norumbega Dam#4 Seaverns Brook DCR/MWRA State High Hazard
Norumbega East Dike Seaverns Brook DCR/MWRA State High Hazard
Schencks Pond Dam Seaverns Brook DCR/MWRA State High Hazard
Stony Brook Reservoir Stony Brook City of Cambridge Municipal High Hazard
Watertown Dam Charles River DCR State Significant Hazard
Weston Reservoir Pine Brook DCR/MWRA State High Hazard
There are no records of dam failures in Watertown or upstream communities. Based on the record of
previous occurrences, dam failure in Watertown is a low frequency event as defined by the Massachusetts
State Hazard Mitigation Plan. This hazard may occur less frequently than once in 50 years to once in 100
years (1% to 2% per year).
JA CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IBC RISK ASSESSMENT 24 of 124
Figure 3 Aerial View of the Watertown Dam
Lath0e:42.36532'N
Llangftd,D:71.1M132"WVF
-
' `..
M ,4-
i`
I
x
i
,.r
r DAM LOCAT11
f
•N
Source: Watertown Dam Emergency Action Plan
WIND-RELATED HAZARDS
Wind-related hazards include hurricanes, tropical storms, and tornadoes, as well as high winds during
nor'easters and thunderstorms. Information on wind related hazards can be found on Map 5 in Appendix
B. The hazard mapping indicates that the 100-year wind speed in Watertown is 1 10 miles per hour. No
tornadoes have been recorded in Watertown.
t CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 25 of 124
Downed trees and limbs can be a problem due to weather conditions such as strong wind or heavy snow
and ice. Tree limbs can down power and communication lines and impact major roadways. The
combination of wind and snow caused significant power line damage during the 2018 Nor'easter.
HURRICANES AND TROPICAL STORMS
A hurricane is a violent wind and rainstorm with wind speeds of 74 to 200 miles per hour. A hurricane is
strongest as it travels over the ocean and is particularly destructive to coastal property as the storm hits
land. Given its location not too distant from the coast, the Town of Watertown's entire area is vulnerable to
hurricanes, which occur between June and November. A tropical storm has similar characteristics, but wind
speeds are below 74 miles per hour. Since 1900, 39 tropical storms have impacted New England (NESEC).
Massachusetts has experienced approximately 32 tropical storms, nine Category 1 hurricanes, five
Category 2 hurricanes and one Category 3 hurricane.
No hurricanes have tracked directly through Watertown. However, as shown in Map 5 in Appendix B, a
tropical storm tracked just west of Watertown through Waltham in 1861, and another tracked just east of
Watertown through Brighton in 1944. A hurricane or storm track is the line that delineates the path of the
eye of a hurricane or tropical storm. The town also experiences the impacts of the wind and rain of
hurricanes and tropical storms regardless of whether the storm track passed through the town.
Table 10: Hurricane Records for Massachusetts, 1938 to 2012
Hurricane Event Date
Great New England Hurricane September 21, 1938
Great Atlantic Hurricane September 14-15, 1944
Hurricane Doug September 1 1-1 2, 1950
Hurricane Carol August 31, 1954
Hurricane Edna* September 11, 1954
Hurricane Diane August 17-19, 1955
Hurricane Donna September 12, 1960
Hurricane Gloria September 27, 1985
Hurricane Bob August 19, 1991
Hurricane Earl September 4, 2010
Tropical Storm Irene August 28, 2011
Hurricane Sandy October 29-30, 2012
Source: National Oceanic and Atmospheric Administration
Hurricane intensity is measured according to the Saffir/Simpson scale, which categorizes hurricane intensity
linearly based upon maximum sustained winds, barometric pressure, and storm surge potential. These are
combined to estimate potential damage. The following gives an overview of the wind speeds, surges, and
range of damage caused by different hurricane categories:
qK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 26 of 124
hh
Scale No. (Category) Winds (mph) Surge (ft) Potential Damage
1 74 — 95 4 - 5 Minimal
2 96 — 1 10 6 - 8 Moderate
3 1 1 1 — 130 9 - 12 Extensive
4 131 — 155 13 - 18 Extreme
5 > 155 >18 Catastrophic
Source: NOAA
Hurricanes typically have regional impacts beyond their immediate tracks. Falling trees and branches are
a significant problem because they can result in power outages when they fall on power lines or block
traffic and emergency routes. Hurricanes are a town-wide hazard in Watertown. Potential hurricane
damages to Watertown have been estimated using HAZUS-MH. Total damages are estimated at $24.8
million for a 100-Year hurricane and $1 12.5 million for a 500-Year hurricane. Other potential impacts
such as debris generation and sheltering needs are detailed in Table 30.
Based on records of previous occurrences, hurricanes in Watertown are a medium frequency event as
defined by the Massachusetts State Hazard Mitigation Plan. This hazard occurs from once in 5 years to
once in 50 years, or a 2% to 20% chance per year.
TORNADOS
A tornado is a violent windstorm characterized by a twisting, funnel-shaped cloud. These events are
spawned by thunderstorms and occasionally by hurricanes, and may occur singularly or in multiples. They
develop when cool air overrides a layer of warm air, causing the warm air to rise rapidly. Most vortices
remain suspended in the atmosphere. Should they touch down, they become a force of destruction. Some
ingredients for tornado formation include:
• Very strong winds in the mid and upper levels of the atmosphere
• Clockwise turning of the wind with height (from southeast at the surface to west aloft)
• Increasing wind speed with altitude in the lowest 10,000 feet of the atmosphere (i.e., 20 mph at
the surface and 50 mph at 7,000 feet)
• Very warm, moist air near the ground with unusually cooler air aloft
• A forcing mechanism such as a cold front or leftover weather boundary from previous shower or
thunderstorm activity
Tornado damage severity is measured by the Fujita Tornado Scale, in which wind speed is not measured
directly but rather estimated from the amount of damage. As of February 1, 2007, the National Weather
Service began rating tornados using the Enhanced Fujita-scale (EF-scale), which allows surveyors to create
more precise assessments of tornado severity. The EF-scale is summarized in Table 1 1 below:
at CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
1APC RISK ASSESSMENT 27 of 124
Table 1 1: Enhanced Fujita Scale
Fujita Scale Derived Operational EF Scale
F Number
Fastest 1/4 3-second EF Number 3-second EF Number 3-second
mile (mph) gust (mph) gust (mph) gust (mph)
0 40 — 72 45 — 78 0 65 — 85 0 65 — 85
1 73 - 112 79 - 117 1 86 - 109 1 86 - 110
2 113 - 157 118 - 161 2 110 - 137 2 111 — 135
3 158 — 207 162 — 209 3 138 — 167 3 136 — 165
4 208 — 260 210 — 261 4 168 — 199 4 166 — 200
5 261— 318 262 — 317 5 200 — 234 5 Over 200
Source: Massachusetts State Hazard Mitigation Plan, 2013
The frequency of tornadoes in eastern Massachusetts is low; on average, there are six tornadoes that
touchdown somewhere in the Northeast region every year. The strongest tornado in Massachusetts history
was the Worcester Tornado in 1953. The most recent tornado events in Massachusetts were in Springfield
in 201 1 and in Revere in 2014. The Springfield tornado caused significant damage and resulted in four
deaths in June of 201 1. The Revere tornado touched down in Chelsea and moved north into Revere's
business district along Broadway, ending near the intersection of Routes 1 and 60. The path was two miles
long and 3/8 mile wide, with wind speeds up to 120 miles per hour. Approximately 65 homes had
substantial damages and 13 homes and businesses were rendered uninhabitable.
There have been no recorded tornadoes in the Town of Watertown. Since 1955 there have been 18
tornadoes in surrounding Middlesex County recorded by the Tornado History Project. Two of these were
F3 tornados, and four were F2. These 18 tornadoes resulted in a total of one fatality and six injuries and
$38.8 million in damages, as summarized in Table 12.
Table 12: Tornado Records for Middlesex Count-
Date Fujita Fatalities Injuries Width Length Damage
10/24/1955 1 0 0 10 0.1 $500-$5000
6/19/1957 1 0 0 100 0.5 $50-$500
7/1 1/1958 2 0 0 17 1.5 $50K-$500K
8/25/1958 2 0 0 50 1 $500-$5000
7/3/1961 0 0 0 10 0.5 $5K-$50K
7/18/1963 1 0 0 50 1 $5K-$50K
8/28/1965 2 0 0 10 2 $50K-$500K
7/1 1/1 970 1 0 0 50 0.1 $5K-$50K
10/3/1970 3 1 0 60 35.4 $50K-$500K
7/1/1971 1 0 1 10 25.2 $5K-$50K
1 1/7/1971 1 0 0 10 0.1 $50-$500
7/21/1972 2 0 4 37 7.6 $500K-$5M
9/29/1974 3 0 1 33 0.1 $50K-$500K
7/18/1983 0 0 0 20 0.4 $50-$500K
9/27/1985 1 0 0 40 0.1 $50-$500K
8/7/1986 1 0 0 73 4 $50K-$500K
8/22/2016 1 0 0 400 .85 $1OK
Source: The Tornado History Project
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 28 of 124
Buildings constructed prior to current building codes may be more vulnerable to damages caused by
tornadoes. Evacuation of impacted areas may be required on short notice. Sheltering and mass feeding
efforts may be required along with debris clearance, search and rescue, and emergency fire and medical
services. Key routes may be blocked by downed trees and other debris, and widespread power outages
are also typically associated with tornadoes.
Although tornadoes are a potential town-wide hazard in Watertown, tornado impacts are relatively
localized compared to severe storms and hurricanes. Damages from any tornado in Watertown would
greatly depend on the track of the tornado. The greatest economic damage would likely result from a
tornado striking the town's commercial districts, including Watertown Square and Arsenal Street.
Based on the record of previous occurrences since 1956, Tornado events in Watertown are a low
frequency event as defined by the 2013 Massachusetts State Hazard Mitigation Plan. This hazard may
occur from once in 50 years to once in 100 years (1% to 2% per year).
NOR'EASTERS
A northeast coastal storm, known as a nor'easter, is typically a large counter-clockwise wind circulation
around a low-pressure center. Featuring strong northeasterly winds blowing in from the ocean over coastal
areas, nor'easters are relatively common in the winter months in New England occurring one to two times a
year. The storm radius of a nor'easter can be as much as 1,000 miles and these storms feature sustained
winds of 10 to 40 mph with gusts of up to 70 mph. These storms are accompanied by heavy rain or snow,
depending on temperatures. Previous occurrences of nor'easters include the following, which are listed in
the Massachusetts State Hazard Mitigation Plan, or have occurred since:
Table 13: Nor'easter Events for Massachusetts, 1978 to 2015
Nor'easter Event Date
Blizzard of 1978 February 1978
Severe Coastal Storm ("Perfect Storm") October 1991
Great Nor'easter of 1992 December 1992
Blizzard/Nor'easter January 2005
Coastal Storm/Nor'easter October 2005
Severe Storms, Inland & Coastal Flooding/Nor'easter April 2007
Winter Storm/Nor'easter January 2011
Severe Storm/Nor'easter October 201 1
Blizzard of 2013 February 2013
Blizzard of 2015 January 2015
March 2015 Nor'easters March 2015
Many of the historic flood events identified in the previous section were precipitated by nor'easters,
including the "Perfect Storm" event in 1991. More recently, blizzards in December 2010, October 2011,
and February 2013, January 2015 were large nor'easters that caused significant snowfall amounts. March
2015 saw four nor'easters which brought significant snowfall to Watertown.
IK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
P APC RISK ASSESSMENT 29 of 124
Watertown is vulnerable to both the wind and precipitation that accompany nor'easters. High winds can
cause damage to structures, fallen trees, and downed power lines leading to power outages. Intense
rainfall can overwhelm drainage systems causing localized flooding of rivers and streams as well as urban
stormwater ponding and localized flooding. Fallen tree limbs as well as heavy snow accumulation and
intense rainfall can impede local transportation corridors, and block access for emergency vehicles.
The entire Town of Watertown could be at risk from the wind, rain, or snow impacts from a nor'easter,
depending on the track and radius of the storm. Due to its inland location, the town would not be subject to
coastal hazards.
Based on the record of previous occurrences, nor'easters in Watertown are high frequency events as
defined by the 2013 Massachusetts State Hazard Mitigation Plan. This hazard may occur more frequently
than once in 5 years (greater than 20% per year).
SEVERE THUNDERSTORMS
While less severe than the other types of storms discussed, thunderstorms can lead to localized damage
and represent a hazard risk for communities. A thunderstorm typically features lightning, strong winds, rain,
and/or hail. Thunderstorms sometime give rise to tornados. On average, these storms are only around 15
miles in diameter and last for about 30 minutes. A severe thunderstorm can include winds of close to 60
mph and rain sufficient to produce flooding. The town's entire area is potentially subject to severe
thunderstorms.
The best available data on previous occurrences of thunderstorms in Watertown is for Middlesex County
through the National Environmental Information Center ('). Between the years 2006 and 2017 NEIC
records show 72 thunderstorm events in Middlesex County (Table 14). These storms resulted in a total of
$1,631,000 in property damages. There were no injuries or deaths reported.
Table 14: Middlesex County Thunderstorm Events, 2006 to 2018
Date Type Magnitude Deaths Injuries Damage
4/1/2006 Thunderstorm Wind 50 0 0 8000
5/21/2006 Thunderstorm Wind 61 0 0 95000
6/23/2006 Thunderstorm Wind 50 0 0 30000
7/1 1/2006 Thunderstorm Wind 50 0 0 10000
7/21/2006 Thunderstorm Wind 50 0 0 35000
7/28/2006 Thunderstorm Wind 50 0 0 15000
8/2/2006 Thunderstorm Wind 50 0 0 15000
5/16/2007 Thunderstorm Wind 50 0 0 0
6/27/2007 Thunderstorm Wind 50 0 0 0
7/6/2007 Thunderstorm Wind 50 0 0 0
7/9/2007 Thunderstorm Wind 50 0 0 0
7/15/2007 Thunderstorm Wind 50 0 0 0
7/28/2007 Thunderstorm Wind 50 0 0 0
7/29/2007 Thunderstorm Wind 50 0 0 0
8/17/2007 Thunderstorm Wind 50 0 0 0
9/8/2007 Thunderstorm Wind 50 0 0 25000
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
PC RISK ASSESSMENT 30 of 124
Date Type Magnitude Deaths Injuries Damage
5/27/2008 Thunderstorm Wind 50 0 0 8000
6/10/2008 Thunderstorm Wind 50 0 0 20000
6/23/2008 Thunderstorm Wind 50 0 0 5000
6/24/2008 Thunderstorm Wind 50 0 0 5000
6/27/2008 Thunderstorm Wind 50 0 0 5000
6/29/2008 Thunderstorm Wind 50 0 0 10000
7/1/2008 Thunderstorm Wind 50 0 0 20000
7/2/2008 Thunderstorm Wind 50 0 0 5000
7/3/2008 Thunderstorm Wind 50 0 0 15000
7/19/2008 Thunderstorm Wind 50 0 0 8000
7/20/2008 Thunderstorm Wind 50 0 0 5000
7/27/2008 Thunderstorm Wind 50 0 0 5000
8/3/2008 Thunderstorm Wind 50 0 0 5000
8/7/2008 Thunderstorm Wind 50 0 0 5000
9/9/2008 Thunderstorm Wind 50 0 0 8000
5/9/2009 Thunderstorm Wind 50 0 0 2000
5/24/2009 Thunderstorm Wind 50 0 0 15000
7/7/2009 Thunderstorm Wind 50 0 0 1000
7/8/2009 Thunderstorm Wind 50 0 0 20000
7/26/2009 Thunderstorm Wind 50 0 0 15000
7/31/2009 Thunderstorm Wind 50 0 0 30000
5/4/2010 Thunderstorm Wind 50 0 0 30000
6/1/2010 Thunderstorm Wind 50 0 0 5000
6/3/2010 Thunderstorm Wind 50 0 0 20000
6/5/2010 Thunderstorm Wind 50 0 0 40000
6/6/2010 Thunderstorm Wind 50 0 0 100000
6/24/2010 Thunderstorm Wind 50 0 0 30000
7/12/2010 Thunderstorm Wind 50 0 0 50000
7/19/2010 Thunderstorm Wind 50 0 0 25000
6/1/201 1 Thunderstorm Wind 50 0 0 5000
6/9/201 1 Thunderstorm Wind 50 0 0 15000
8/2/201 1 Thunderstorm Wind 50 0 0 1000
8/19/201 1 Thunderstorm Wind 50 0 0 15000
6/8/2012 Thunderstorm Wind 50 0 0 25000
6/23/2012 Thunderstorm Wind 45 0 0 5000
7/4/2012 Thunderstorm Wind 50 0 0 10000
7/18/2012 Thunderstorm Wind 70 0 0 350000
9/7/2012 Thunderstorm Wind 50 0 0 10000
9/8/2012 Thunderstorm Wind 40 0 0 3000
6/17/2013 Thunderstorm Wind 50 0 0 25000
6/18/2013 Thunderstorm Wind 45 0 0 10000
6/24/201 3 Thunderstorm Wind 45 0 0 3000
7/23/2013 Thunderstorm Wind 50 0 0 20000
7/29/2013 Thunderstorm Wind 50 0 0 5000
CITY OF WATERTOWN —DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAP RISK ASSESSMENT 31 of 124
Date Type Magnitude Deaths Injuries Damage
7/3/201 A Thunderstorm Wind 50 0 0 75000
7/7/201 A Thunderstorm Wind 87 0 0 100000
7/15/201 A Thunderstorm Wind 50 0 0 25000
7/28/201 A Thunderstorm Wind 50 0 0 50000
9/6/201 A Thunderstorm Wind 50 0 0 15000
5/28/2015 Thunderstorm Wind 45 0 0 5000
8/4/2015 Thunderstorm Wind 50 0 0 40000
8/15/2015 Thunderstorm Wind 50 0 0 25000
2/25/2016 Thunderstorm Wind 50 0 0 30000
3/17/2016 Thunderstorm Wind 45 0 0 5000
7/22/2016 Thunderstorm Wind 50 0 0 14,000
7/23/2016 Thunderstorm Wind 50 0 0 0
8/22/2016 Thunderstorm Wind 50 0 0 0
9/1 1/2016 Thunderstorm Wind 50 0 0 10,000
5/1 8/2017 Thunderstorm Wind 50 0 0 0
6/13/2017 Thunderstorm Wind 52 0 0 0
6/23/2017 Thunderstorm Wind 52 0 0 1,000
6/27/2017 Thunderstorm Wind 50 0 0 0
7/12/2017 Thunderstorm Wind 50 0 0 0
8/2/2017 Thunderstorm Wind 50 0 0 0
9/6/2017 Thunderstorm Wind 50 0 0 0
5/15/201 8 Thunderstorm Wind 40 0 0 0
6/18/2018 Thunderstorm Wind 50 0 0 0
6/25/201 8 Thunderstorm Wind 43 0 0 0
*Magnitude refers to maximum wind speed
Source: NOAA, National Environmental Information Center
Severe thunderstorms are a town-wide hazard for Watertown. The town's vulnerability to severe
thunderstorms is similar to that of nor'easters. High winds can cause falling trees and power outages, as
well as obstruction of key routes and emergency access. Heavy precipitation may also cause localized
flooding, both riverine and urban drainage related.
Based on the record of previous occurrences, severe thunderstorms in Watertown are high frequency
events as defined by the 2013 Massachusetts State Hazard Mitigation Plan. This hazard may occur more
frequently than once in 5 years (greater than 20% per year).
WINTER STORMS
Winter storms, including heavy snow, blizzards, and ice storms, are the most common and most familiar of
the region's hazards that affect large geographic areas. The majority of blizzards and ice storms in the
region cause more inconvenience than they do serious property damage, injuries, or deaths. However,
periodically, a storm will occur which is a true disaster, and necessitates intense large-scale emergency
response. The impacts of winter storms are often related to the weight of snow and ice, which can cause
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 32 of 124
roof collapses and also causes tree limbs to fall. This in turn can cause property damage and potential
injuries. Power outages may also result from fallen trees and utility lines.
Winter storms are a potential town-wide hazard in Watertown. The average annual snowfall Watertown
is 48-72 inches (see Map 6 in Appendix B). A number of public safety issues can arise during snow storms.
Impassible streets are a challenge for emergency vehicles and affect residents and employers. Snow-
covered sidewalks force people to walk in streets, which are already less safe due to snow, slush, puddles,
and ice. Large piles of snow can also block sight lines for drivers, particularly at intersections. Not all
residents are able to clear their properties, especially the elderly. Refreezing of melting snow can cause
dangerous roadway conditions. In addition, transit operations may be impacted, as they were in the 2015
blizzard which caused the closure of the MBTA system for one day and limited services on several transit
lines for several weeks.
HEAVY SNOW AND BLIZZARDS
A blizzard is a winter snow storm with sustained or frequent wind gusts to 35 mph or more, accompanied
by falling or blowing snow which reduces visibility to or below 1/4 mile. These conditions must be the
predominant condition over a three hour period. Extremely cold temperatures are often associated with
blizzard conditions, but are not a formal part of the definition. The hazard related to the combination of
snow, wind, and low visibility significantly increases when temperatures drop below 20 degrees.
Winter storms are a combination hazard because they often involve wind, ice, and heavy snow fall. The
National Weather Service defines "heavy snow fall" as an event generating at least four inches of
snowfall within a 12 hour period. Winter Storms are often associated with a Nor'easter event, a large
counter-clockwise wind circulation around a low-pressure center often resulting in heavy snow, high winds,
and rain.
The Northeast Snowfall Impact Scale (NESIS), developed by Paul Kocin of The Weather Channel and Louis
Uccellini of the National Weather Service (Kocin and Uccellini, 2004), characterizes and ranks high impact
northeast snowstorms. These storms have large areas of 10 inch snowfall accumulations and greater. NESIS
has five categories: Extreme, Crippling, Major, Significant, and Notable. NESIS scores are a function of the
area affected by the snowstorm, the amount of snow, and the number of people living in the path of the
storm. The largest NESIS values result from storms producing heavy snowfall over large areas that include
major metropolitan centers. The NESIS categories are summarized in Table 15below:
Table 15: NESIS Categories
Category NESIS Value Description
1 1 — 2.499 Notable
2 2.5 — 3.99 Significant
3 4 — 5.99 Major
4 6 — 9.99 Crippling
5 1 0+ Extreme
Source:Massachusetts State Hazard Mitigation Plan, 2013
JA CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IBC RISK ASSESSMENT 33 of 124
The most significant winter storm in recent history was the "Blizzard of 1978," which resulted in over three
feet of snowfall and multiple day closures of roadways, businesses, and schools. In Watertown, blizzards
and severe winter storms have occurred in the following years, shown in Table 16:
Table 16: Severe Winter Storm Records for Massachusetts
Severe Winter Storm Event Date
Blizzard of 1978 February 1978
Blizzard March 1993
Blizzard January 1996
Severe Snow Storm March 2001
Severe Snow Storm December 2003
Severe Snow Storm January 2004
Severe Snow Storm January 2005
Severe Snow Storm April 2007
Severe Snow Storm December 2010
Severe Snow Storm January 2011
Blizzard of 2013 February 2013
Blizzard of 2015 January 2015
Severe Snow Storm March 2018
Source: National Oceanic and Atmospheric Administration
The Town of Watertown does not keep local records of winter storms. Data for Middlesex County, which
includes Watertown, is the best available data to help understand previous occurrences and impacts of
heavy snow events. According to National Climate Data Center (NEIC) records, from 1996 to 2016,
Middlesex County experienced 75 heavy snowfall events, resulting in no injuries or deaths, and $229,000
in property damage. See Table 17 for and heavy snow events and impacts in Middlesex County.
Table 17: Heavy Snow Events and Impacts in Middlesex County, 2000 to 2018
Date Type Deaths Injuries Property Damage
1/13/2000 Heavy Snow 0 0 0
1/25/2000 Heavy Snow 0 0 0
2/18/2000 Heavy Snow 0 0 0
12/30/2000 Heavy Snow 0 0 0
1/20/2001 Heavy Snow 0 0 0
2/5/2001 Heavy Snow 0 0 0
3/5/2001 Heavy Snow 0 0 0
3/9/2001 Heavy Snow 0 0 0
3/30/2001 Heavy Snow 0 0 0
12/8/2001 Heavy Snow 0 0 0
3/20/2002 Heavy Snow 0 0 0
3/16/2004 Heavy Snow 0 0 0
2/24/2005 Heavy Snow 0 0 0
1 2/1 3/2007 Heavy Snow 0 0 0
1 2/16/2007 Heavy Snow 0 0 0
1 2/19/2007 Heavy Snow 0 0 0
1/14/2008 Heavy Snow 0 0 28000
1/14/2008 Heavy Snow 0 0 20000
qK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IpC RISK ASSESSMENT 34 of 124
� 1/14/2008 Heavy Snow 0 0 20000
� 2/22/2008 Heavy Snow 0 0 0
� 3/1/2008 Heavy Snow 0 0 0
� 12/19/2008 Heavy Snow 0 0 0
� 12/20/2008 Heavy Snow 0 0 8000
� 12/21/2008 Heavy Snow 0 0 0
� 12/31/2008 Heavy Snow 0 0 0
� 1/10/2009 Heavy Snow 0 0 0
� 1/11/2009 Heavy Snow 0 0 0
� 1/18/2009 Heavy Snow 0 0 0
� 3/1/2009 Heavy Snow 0 0 0
� 3/2/2009 Heavy Snow 0 0 0
� 12/9/2009 Heavy Snow 0 0 15000
� 12/9/2009 Heavy Snow 0 0 500
� 12/19/2009 Heavy Snow 0 0 0
� 12/20/2009 Heavy Snow 0 0 0
� 1/18/2010 Heavy Snow 0 0 0
� 2/16/2010 Heavy Snow 0 0 15000
� 2/23/2010 Heavy Snow 0 0 8000
1/12/2011 Heavy Snow 0 0 0
� 1/26/2011 Heavy Snow 0 0 0
� 10/29/2011 Heavy Snow 0 0 30000
� 12/29/2012 Heavy Snow 0 0 0
� 2/8/2013 Heavy Snow 0 0 0
� 2/8/2013 Heavy Snow 0 0 0
� 2/23/2013 Heavy Snow 0 0 0
� 3/7/2013 Heavy Snow 0 0 0
� 3/18/2013 Heavy Snow 0 0 0
� 12/14/2013 Heavy Snow 0 0 0
� 12/17/2013 Heavy Snow 0 0 0
� 1/2/2014 Heavy Snow 0 0 0
� 1/18/201A Heavy Snow 0 0 0
� 2/5/2014 Heavy Snow 0 0 0
� 2/13/201A Heavy Snow 0 0 0
� 2/18/201A Heavy Snow 0 0 0
� 11/26/2014 Heavy Snow 0 0 10000
� 1/24/2015 Heavy Snow 0 0 0
� 1/26/2015 Heavy Snow 0 0 0
� 2/2/2015 Heavy Snow 0 0 0
� 2/8/2015 Heavy Snow 0 0 0
� 2/14/2015 Heavy Snow 0 0 0
� 2/5/2016 Heavy Snow 0 0 70000
2/5/2016 Heavy Snow 0 0 5000
� 3/21/2016 Heavy Snow 0 0 0
4/4/2016 Heavy Snow 0 0 0
� 12/29/2016 Heavy Snow 0 0 0
� 3/14/2017 Heavy Snow 0 0 0
Source: NOAA, National Environmental Information Center
Blizzards are considered to be high frequency events based on past occurrences, as defined by the
Massachusetts State Hazard Mitigation Plan, 2013. This hazard occurs more than once in five years, with a
greater than 20% chance of occurring each year.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 35 of 124
ICE STORMS
The ice storm category covers a range of different weather phenomena that collectively involve rain or
snow being converted to ice in the lower atmosphere leading to potentially hazardous conditions on the
ground. Hail size typically refers to the diameter of the hailstones. Warnings and reports may report hail
size through comparisons with real-world objects that correspond to certain diameters, shown in Table 18.
Table 18: Hail Size Comparisons
Description Diameter (inches)
Pea 0.25
Marble or mothball 0.50
Penny or dime 0.75
Nickel 0.88
Quarter 1.00
Half dollar 1.25
Walnut or ping pong ball 1.50
Golf ball 1.75
Hen's egg 2.00
Tennis ball 2.50
Baseball 2.75
Tea cup 3.00
Grapefruit 4.00
Softball 4.50
While ice pellets and sleet are examples of these, the greatest hazard is created by freezing rain
conditions, which is rain that freezes on contact with hard surfaces leading to a layer of ice on roads,
walkways, trees, and other surfaces. The conditions created by freezing rain can make driving particularly
dangerous and emergency response more difficult. The weight of ice on tree branches can also lead to
falling branches damaging electric lines.
Town-specific data for previous ice storm occurrences are not collected by the Town of Watertown. The
best available local data is for Middlesex County through the National Environmental Information Center.
Middlesex County, which includes the Town of Watertown, experienced 46 events from 2000 to 2017 (see
Table 19).
Table 19: Middlesex County Hail Events, 2000-2018
Date Event Magnitude Deaths Injuries Damage
7/18/2000 Hail 1 0 0 0
6/20/2001 Hail 1.75 0 0 0
7/12/2001 Hail 1.5 0 0 0
5/27/2002 Hail 0.75 0 0 0
6/2/2002 Hail 0.75 0 0 0
8/13/2003 Hail 0.75 0 0 0
7/2/2004 Hail 0.75 0 0 0
8/20/2004 Hail 0.88 0 0 75,000
5/21/2006 Hail 0.75 0 0 0
1 CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 36 of 124
7/1 1/2006 Hail 1 0 0 0
7/28/2006 Hail 0.75 0 0 0
6/5/2007 Hail 1.25 0 0 0
6/22/2007 Hail 0.75 0 0 0
7/9/2007 Hail 1 0 0 0
7/28/2007 Hail 0.88 0 0 0
6/23/2008 Hail 0.75 0 0 0
6/24/2008 Hail 0.75 0 0 0
7/1/2008 Hail 0.88 0 0 0
7/2/2008 Hail 0.75 0 0 0
8/3/2008 Hail 0.75 0 0 0
8/7/2008 Hail 1 0 0 0
8/10/2008 Hail 0.75 0 0 0
5/24/2009 Hail 1 0 0 0
6/27/2009 Hail 0.88 0 0 0
7/7/2009 Hail 0.75 0 0 0
7/8/2009 Hail 1.75 0 0 0
5/4/2010 Hail 0.75 0 0 0
5/7/2011 Hail 0.75 0 0 0
6/1/201 1 Hail 0.75 0 0 0
8/2/2011 Hail 0.75 0 0 0
8/19/2011 Hail 0.75 0 0 0
3/13/2012 Hail 1.25 0 0 0
3/14/2012 Hail 1 0 0 0
6/23/2012 Hail 0.75 0 0 0
7/18/2012 Hail 1 0 0 0
10/30/2012 Hail 1 0 0 0
6/17/2013 Hail 0.75 0 0 0
5/25/2014 Hail 0.75 0 0 0
7/3/2014 Hail 1 0 0 0
8/7/2014 Hail 0.75 0 0 0
9/6/2014 Hail 0.88 0 0 0
8/4/2015 Hail 1 0 0 0
8/15/2015 Hail 0.75 0 0 0
7/23/2016 Hail .75 0 0 0
6/27/2017 Hail 1.00 0 0 0
8/2/2017 Hail .75 0 0 0
*Magnitude refers to diameter of hail stones in inches
Source: NOAA, National Environmental Information Center
Ice storms are considered to be medium frequency events based on past occurrences, and as defined by
the Massachusetts State Hazard Mitigation Plan. This hazard occurs once in five years to once in 50 years,
with a 2% to 20% chance of occurring each year.
IK CITY OF WATERTOWN —DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAIPC RISK ASSESSMENT 37 of 124
GEOLOGIC HAZARDS
Geologic hazards include earthquakes, landslides, sinkholes, subsidence, and unstable soils such as fill,
peat, and clay. Town officials did not identify any problems with areas of geologic instability, such as
sinkholes or subsidence. Although new construction under the most recent building codes generally will be
built to seismic standards, there are still many structures in town which pre-date the most recent building
code. Information on geologic hazards in Watertown can be found on Map 4 in Appendix B.
EARTHQUAKES
Damage in an earthquake stems from ground motion, surface faulting, and ground failure in which weak or
unstable soils, such as those composed primarily of saturated sand or silts, liquefy. The effects of an
earthquake are mitigated by distance and ground materials between the epicenter and a given location.
An earthquake in New England affects a much wider area than a similar earthquake in California due to
New England's solid bedrock geology (NESEC).
Seismologists use a magnitude scale known as the Richter scale to express the seismic energy released by
each earthquake. The typical effects of earthquakes in various ranges are summarized in Table 20 below:
Table 20: Richter Scale and Effects
Richter Magnitudes Earthquake Effects
Less than 3.5 Generally not felt, but recorded
3.5- 5.4 Often felt, but rarely causes damage
Under 6.0 At most slight damage to well-designed buildings. Can cause major
damage to poorly constructed buildings over small regions.
6.1-6.9 Can be destructive in areas up to about 100 km. across where people
live.
7.0- 7.9 Major earthquake. Can cause serious damage over larger areas.
8 or greater
Great earthquake. Can cause serious damage in areas several hundred
meters across.
Source: Nevada Seismological Library (NSL),2005
According to the State Hazard Mitigation Plan, New England experiences an average of five earthquakes
per year. From 1 668 to 2007, 355 earthquakes were recorded in Massachusetts (NESEC). Most have
originated from the La Malbaie fault in Quebec or from the Cape Anne fault located off the coast of
Rockport. The region has experienced larger earthquakes in the distant past, including a magnitude 5.0
earthquake in 1727 and a 6.0 earthquake that struck in 1755 off the coast of Cape Anne. More recently,
a pair of damaging earthquakes occurred near Ossipee, NH in 1940. A 4.0 earthquake centered in Hollis,
Maine in October 2012 was felt in the Boston area. Historic records of some of the more significant
earthquakes in the region are shown in Table 21.
Table 21: Historical Earthquakes in Massachusetts or Surrounding Area
Location Date Magnitude
MA - Cape Ann 1 1/10/1727 5
MA - Cape Ann 1 2/29/1727 NA
MA - Cape Ann 2/10/1728 NA
MA - Cape Ann 3/30/1729 NA
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC RISK ASSESSMENT 38 of 124
Location Date Magnitude
MA - Cape Ann 12/9/1729 NA
MA - Cape Ann 2/20/1730 NA
MA - Cape Ann 3/9/1730 NA
MA - Boston 6/24/1741 NA
MA - Cape Ann 6/14/1744 4.7
MA - Salem 7/1/1744 NA
MA - Off Cape Ann 1 1/18/1755 6
MA - Off Cape Cod 1 1/23/1755 NA
MA - Boston 3/1 2/1761 4.6
MA - Off Cape Cod 2/2/1766 NA
MA - Offshore 1/2/1785 5.4
MA 12/25/1800 NA
Wareham/Taunton
MA - Woburn 10/5/1 817 4.3
MA - Marblehead 8/25/1846 4.3
MA - Brewster 8/8/1 847 4.2
MA - Boxford 5/12/1880 NA
MA - Newbury 1 1/7/1907 NA
MA - Wareham 4/25/1 924 NA
MA - Cape Ann 1/7/1925 4
MA - Nantucket 10/25/1965 NA
MA - Boston 12/27/74 2.3
VA - Mineral 8/23/1 1 5.8
MA - Nantucket 4/1 2/1 2 4.5
ME - Hollis 10/17/12 4.0
Source: City of Boston, Hazard Identification and Risk Assessment
One measure of earthquake risk is ground motion, which is measured as maximum peak horizontal
acceleration, expressed as a percentage of gravity (%g). The range of peak ground acceleration in
Massachusetts is from 10 %g to 20 %g, with a 2% probability of exceedance in 50 years (see Figure 4).
Watertown is in the middle part of the range for Massachusetts, at 14 %g to 16 %g, making it a
relatively moderate area of earthquake risk within the state, although the state as a whole is considered to
have a low risk of earthquakes compared to the rest of the country. There has been one earthquake with
an epicenter in Watertown. See Map 4 in Appendix B.
Although New England has not experienced a damaging earthquake since 1755, seismologists state that a
serious earthquake occurrence is possible. There are five seismological faults in Massachusetts, but there is
no discernible pattern of previous earthquakes along these fault lines. Earthquakes occur without warning
and may be followed by aftershocks. The majority of older buildings and infrastructure were constructed
without specific earthquake resistant design features.
1 CITY OF WATERTOWN-DRAFT HAZARD MITIGATION PLAN- 2019 UPDATE
P APC RISK ASSESSMENT 39 of 124
Figure 4: State of Massachusetts Earthquake Probability Map
Ea tVhgrrarlke 1fagrlilndes 166E-199 7.faidl Line Larallem.and
epe-k GraA FFd A reeler adaan f )w0li 1.Prabrrhr{it&•a f Trrredarree in 96
V.-
NY
Mwm
c i
k
i
rF
Lapend PMF Qaurei �_� ••
e.� .+...,.x�+n�+.trr.11�ie[ Fwrw►�.wwwWih.Gwr.-�rr r .
- - 5� • � • wwFrrrrF•w,�S�rtF.Fad.warr..�::r�.�..
eFtirrrsr�Faa� �� � 'i�l
r a • � ..rt Iw.wrtart`.
Source: Massachusetts State Hazard Mitigation Plan
Earthquakes are a hazard with multiple impacts beyond the obvious building collapse. Buildings may suffer
structural damage which may or may not be readily apparent. Earthquakes can cause major damage to
roadways, making emergency response difficult. Water lines and gas lines can break, causing flooding
and fires. Another potential vulnerability is equipment within structures. For example, a hospital may be
structurally engineered to withstand an earthquake, but if the equipment inside the building is not properly
secured, the operations at the hospital could be severely impacted during an earthquake. Earthquakes can
also trigger landslides.
Much of the development in town pre-dates the current building code and could be vulnerable in the event
of a severe earthquake. Potential earthquake damages to Watertown have been estimated using HAZUS-
MH. Total building damages are estimated at $891 million for a 5.0 magnitude earthquake and $5 billion
for a 7.0 magnitude earthquake. Other potential impacts such as debris generation and sheltering needs
are detailed in Table 31.
According to the Boston College Weston Observatory, in most parts of New England, there is a one in ten
chance that a potentially damaging earthquake will occur in a 50 year time period. The Massachusetts
State Hazard Mitigation Plan classifies earthquakes as "very low° frequency events that occur less
frequently than once in 100 years, or a less than 1% chance per year. Earthquakes are a potential town-
wide hazard in Watertown.
1K CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
P APC RISK ASSESSMENT 40 of 124
LANDSLIDES
According to the U.S. Geological Survey, "The term landslide includes a wide range of ground movement,
such as rock falls, deep failure of slopes, and shallow debris flows. Although gravity acting on an over
steepened slope is the primary reason for a landslide, there are other contributing factors." Among the
contributing factors are: erosion by rivers or ocean waves over steepened slopes; rock and soil slopes
weakened through saturation by snowmelt or heavy rains; earthquake created stresses that make weak
slopes fail; excess weight from accumulation of rain or snow; and stockpiling of rock or ore from waste
piles or man-made structures.
Landslides can result from human activities that destabilize an area or can occur as a secondary impact
from another natural hazard, such as flooding. In addition to structural damage to buildings and the
blockage of transportation corridors, landslides can lead to sedimentation of water bodies. Typically, a
landslide occurs when the condition of a slope changes from stable to unstable. Natural precipitation such
as heavy snow accumulation, torrential rain, and run-off may saturate soil, creating instability enough to
contribute to a landslide. A lack of vegetation and root structure that normally stabilize soil can destabilize
hilly terrain.
There is no universally accepted measure of landslide extent, but it has been represented as a measure of
the destructiveness. Table 22 below summarizes the estimated intensity for a range of landslides. Fast
moving rock falls have the highest intensity while slow moving landslides have the lowest intensity.
Table 22: Landslide Volume and Velocity
Estimate Volume (m3) Expected Landslide Velocity
Fast moving (rock fall) Rapid moving (debris flow) Slow moving (slide)
<0.001 Slight intensity -- --
<0.5 Medium intensity -- --
>0.5 High intensity --- --
<500 High intensity Slight intensity --
500-10,000 High intensity Medium intensity Slight intensity
10,000—50,000 Very high intensity High intensity Medium intensity
>500,000 -- Very high intensity High intensity
>>500,000 -- -- Very high intensity
Source:A Geomorphological Approach to the Estimation of Landslide Hazards and Risks in Umbria, Central Italy,
M. Cardinali et al, 2002
Watertown has been classified as having a low risk for landslides (see Map 4, Appendix B). Local officials
did not identify any significant issues related to landslides.
Should a landslide occur in the future, the type and degree of impacts would be highly localized. The
town's vulnerabilities could include damage to structures, damage to transportation and other
infrastructure, and localized road closures. Injuries and casualties, while possible, would be unlikely given
the low extent and impact of landslides in Watertown. Based on past occurrences and the Massachusetts
Hazard Mitigation Plan, landslides are low frequency events that can occur once in 50 to100 years (a 1%
to 2% chance of occurring each year).
JK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
PC RISK ASSESSMENT 41 of 124
FIRE-RELATED HAZARDS
A brush fire is an uncontrolled fire occurring in a forested or grassland area. In the Boston Metro region
these fires rarely grow to the size of a wildfire, as seen more typically in the western U.S. As their name
implies, brush fires typically burn no more than the underbrush of a forested area. There are three
different classes of wildfires:
• Surface fires are the most common type and burn along the floor of a forest, moving slowly and
killing or damaging trees
• Ground fires are usually started by lightning and burn on or below the forest floor
• Crown fires spread rapidly by wind, jumping along the tops of trees
Wildfire season can begin in March and usually ends in late November. The majority of wildfires typically
occur in April and May, when most vegetation is void of any appreciable moisture, making them highly
flammable. Once "green-up" takes place in late May to early June, the fire danger usually is reduced
somewhat.
A wildfire differs greatly from other fires by its extensive size, the speed at which it can spread out from
its original source, its potential to unexpectedly change direction, and its ability to jump gaps such as
roads, rivers, and fire breaks.
These fires can present a hazard where there is the potential for them to spread into developed or
inhabited areas, particularly residential areas where sufficient fuel materials might exist to allow the fire
the spread into homes. Protecting structures from fire poses special problems, and can stretch firefighting
resources to the limit. If heavy rains follow a fire, other natural disasters can occur, including landslides,
mudflows, and floods. If the wild fire destroys the ground cover, then erosion becomes one of several
potential problems.
Potential Brushfire Hazard Areas
According to local officials, brush fires in Watertown are not a significant issue. The town sees several
brush fires annually, but these fires have not caused significant property damage or injuries. The Town
identified only three small areas of potential brush fires, Whitney Hill, the wooded area off of Greenough
Boulevard, and the Bike Path along Arsenal Street and Pleasant Street. These are shown on Map 8 in
Appendix B as sites number 5, 6, and 9respectively.
Wildfires in Massachusetts are measured by the number of fires and acres burned. The most recent data
available for wildfires in Massachusetts, shown in Figure 5h, indicates that the wildfire extent in Watertown
consists of 0.25 to 9 to 26 acres burned, with zero to 20 recordable fires from 2001 to 2009.
at CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 42 of 124
Figure 5: Massachusetts Wildfires, 2001 to 2009
45
011
l op
• • 4V 6
10
� #
,40
•
ti� rr Yi-' i
4
t
Source: Massachusetts State Hazard Mitigation Plan
Based on past occurrences and the Massachusetts Hazard Mitigation Plan 2013, brushfires are of Medium
frequency, events that occur from once in 5 years to once in 50 years (2% to 20% probability per year).
EXTREME TEMPERATURES
Extreme temperatures occur when either high temperature or low temperatures relative to average local
temperatures occur. These can occur for brief periods of time and be acute, or they can occur over long
periods of time where there is a long stretch of excessively hot or cold weather.
Watertown has four well-defined seasons. The seasons have several defining factors, with temperature one
of the most significant. Extreme temperatures can be defined as those that are far outside of the normal
seasonal ranges for Massachusetts. The average temperature for winter (December to February) in
Massachusetts is 31.8°F. The average temperature for summer (June to August) is 71 OF. Extreme
temperatures are a town-wide hazard.
EXTREME COLD
For extreme cold, temperature is typically measured using the Wind Chill Temperature Index, which is
provided by the National Weather Service (NWS). The latest version of the index was implemented in
2001 and is meant to show how cold conditions feel on unexposed skin and can lead to frostbite. The
index is provided in Figure 6.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
APC RISK ASSESSMENT 43 of 124
Figure 6: Wind Chill Temperature Index and Frostbit Risk
Temperature(4)
Calm 1 35 30 25 20 IS 10 S I i I 1 1 -45
36 31 25 19 13 7 1 -5 -11 -1i +
+
37 2 19 13 b 4 -7 l3
+ 30 24 17 11 4 -2 -9 -15
CL
+ 29 22 1 8 1 -5 -12 F
1 21 14 7 Q -7 14
+
2b 14 12 2 9 16 +
2 1 12 4 3 1b i7 .0
+ +
i ' M '
Source: National Weather Service
Extreme cold is a dangerous situation that can result in health emergencies for susceptible people, such as
those without shelter, those who are stranded, or those who live in homes that are poorly insulated or
without heat. The elderly and people with disabilities are often most vulnerable. In Watertown, 15.4 percent
of the population are over 65 and 10 percent of the population has a disability
The Town of Watertown does not collect data for previous occurrences of extreme cold. The best available
local data are for Middlesex County, through the National Environmental Information Center (NEIC). There
are three extreme cold events on record since 2000 for the county, which caused no deaths, no injuries, or
property damage (Table 23).
i able :z3: Middlesex County Extreme Cold and Wind Chill Occurrences
Date Deaths Injuries Damage
2/15/2015 0 0 0
2/16/2015 0 0 0
2/14/2016 0 0 0
Source: NOAA, National Environmental Information Center
EXTREME HEAT
A heat wave in Massachusetts is defined as three or more consecutive days above 90°F. Another measure
used for identifying extreme heat events is through a Heat Advisory from the NWS. These advisories are
issued when the heat index (see Figure 7) is forecasted to exceed 100°F for two or more hours; an
excessive heat advisory is issued if the forecast predicts the temperature to rise above 105°F.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 44 of 124
Figure 7: Heat Index Chart
Temper tm ff)
SO 02 U N N IN S2 94 96 1 99 1 10a 102 1IU V say 110
40 8p 01 C}1 K M 91 94 97 1131 106 109 114 1 t9 1N
4.5 Ap �12 PA 87 99 90 96 1N 11M IM 114 119 124
50 81 83 65 88 91 95 95 15:3 106 113 118 124
55 81 84 ffi 85 93 9? 101 106 112 117 124
fir] 82 M U 91 % 100 1i5 iF0 116 123
96 A2 85 69 93 98 Ip1 1i9 1" 121
70 83 85 T 95 1D 1M 112 M
5__ 84 88 92 97 103 109 116 124
go 84 89 1-4 IM 106 113 121
m 85 90 t02 110 117
60 86 91 % .105 113 122
113 8B 93 100 1UB [it
IN 87 95 103 12 121
Smsme.muscle crap.and'm heal exl;e imbn pinsbk"mt WsxVd
i;xlferne Gaut an X_F-105'F &r&cM.mtxle ararnm.endbr heat exhauVian3 pnnible•pith prolonged
expom uKkrphysul xtivlt .
Ca'lion =:• F-9 `F Fatigue pmb@ trlh progn9ed enpo9ura and ar pbysi al
Extreme heat poses a potentially greater risk to the elderly, children, and people with certain medical
conditions, such as heart disease. In Watertown children under 5 years old make up 6.7 percent of the
population, and 15.4 percent are over 65 years old. However, even young and healthy individuals can
succumb to heat if they participate in strenuous physical activities during hot weather. Hot summer days can
also worsen air pollution. With increased extreme heat, urban areas of the northeast are likely to
experience more days that fail to meet air quality standards.
The Town of Watertown does not collect data on excessive heat occurrences. The best available local data
are for Middlesex County, through the National Environmental Information Center. Since 200, there has
been one excessive heat day, which did not result in injury, death, or property damage (see Table 24).
r able 24: Middlesex County Extreme Hear Occur.
Date Deaths Injuries Damage ($)
7/6/2010 0 0 0
Total 0 0 0
Source: NOAA, National Environmental Information Center
Extreme temperatures are medium frequency events based on past occurrences, and as defined by the
2013 Massachusetts State Hazard Mitigation Plan. Both extreme cold and hot weather events occur
between once in five years to once in 50 years, or a 2% to 20% chance of occurring each year.
DROUGHT
Drought is a temporary irregularity in precipitation and differs from aridity since the latter is restricted to
low rainfall regions and is a permanent feature of climate. Drought is a period characterized by long
1 CITY OF WATERTOWN-DRAFT HAZARD MITIGATION PLAN- 2019 UPDATE
MAPC RISK ASSESSMENT 45 of 124
durations of below normal precipitation. Drought conditions occur in virtually all climatic zones, yet its
characteristics vary significantly from one region to another since it is relative to the normal precipitation in
that region. Drought can affect agriculture, water supply, aquatic ecology, wildlife, and plant life.
In Massachusetts, droughts are caused by the prevalence of dry northern continental air and a decrease in
coastal- and tropical-cyclone activity. During the 1960s, a cool drought occurred because dry air from the
north caused lower temperatures in the springs and summers of 1962 through 1965. The northerly winds
drove frontal systems to sea along the southeast coast and prevented the northeastern states from
receiving moisture (U.S. Geological Survey). This is considered the record drought in Massachusetts modern
history.
Average annual precipitation in Massachusetts is 44 inches per year, with approximately three to four inch
average amounts for each month of the year. Regional monthly precipitation ranges from zero to 17 inches
and statewide annual precipitation ranges from 30 to 61 inches. Thus, in the driest calendar year (1965),
the statewide precipitation total of 30 inches was only 68% of the average total.
Although Massachusetts is relatively small, it has a number of distinct regions that experience significantly
different weather patterns and react differently to the amounts of precipitation they receive. The DCR
precipitation index divides the state into six regions: Western, Central, Connecticut River Valley, Northeast,
Southeast, and Cape and Islands. Watertown is located in the Northeast region. Drought is a potential
town-wide hazard in Watertown.
Five levels of drought have been developed to characterize drought severity: Normal, Advisory, Watch,
Warning, and Emergency. These drought levels are based on the conditions of natural resources and are
intended to provide information on the current status of water resources. The levels provide a basic
framework from which to take actions to assess, communicate, and respond to drought conditions.
The drought levels begin with a normal situation where data are routinely collected and distributed, move
to heightened vigilance with increased data collection during an advisory, and to increased assessment
and proactive education during a watch. Water restrictions might be appropriate at the watch or warning
stage, depending on the capacity of each individual water supply system. A warning level indicates a
severe situation and the possibility that a drought emergency may be necessary. A drought emergency is
one in which mandatory water restrictions or use of emergency supplies become necessary. Drought levels
are used to coordinate both state agency and local response to drought situations.
As dry conditions can have a range of different impacts, a number of drought indices are available to
assess these various impacts. Massachusetts uses a multi-index system that takes advantage of several of
these indices to determine the severity of a given drought or extended period of dry conditions. Drought
level is determined monthly based on the number of indices which have reached a given drought level.
Drought levels are declared on a regional basis for each of the six regions in Massachusetts. County by
county or watershed-specific determinations may also be made. A determination of drought level is based
on seven indices:
1. Standardized Precipitation Index (SPI) reflects soil moisture and precipitation.
2. Crop Moisture Index (CMI) reflects soil moisture conditions for agriculture.
jK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAIPC RISK ASSESSMENT 46 of 124
3. Keetch Byram Drought Index (KBDI) is designed for fire-potential assessment.
4. Precipitation Index is a comparison of measured precipitation amounts to historic normal
precipitation.
5. The Groundwater Level Index is based on the number of consecutive month's groundwater levels
below normal (lowest 25% of period of record).
b. The Stream flow Index is based on the number of consecutive months that stream flow levels are
below normal (lowest 25% of period of record).
7. The Reservoir Index is based on the water levels of small, medium, and large index reservoirs
across the state, relative to normal conditions for each month.
Determinations regarding the end of a drought or reduction of the drought level focus on two key drought
indicators: precipitation and groundwater levels. These two factors have the greatest long-term impact on
stream flow, water supply, reservoir levels, soil moisture, and potential for forest fires.
Watertown does not collect data relative to drought events. Because drought tends to be a regional
natural hazard, this plan references state data as the best available data for drought. The statewide scale
is a composite of the six regions in the state. Regional composite precipitation values are based on monthly
values from six stations, and three stations in the smaller regions (Cape and Islands and West regions).
Figure 8 depicts the incidents of drought levels' occurrence in Massachusetts from 1 850 to 2012 using the
Standardized Precipitation Index (SPI) parameter alone. On a monthly basis, the state would have been in
a Drought Watch to Emergency condition 1 1% of the time between 1 850 and 2012. Table 25 summarizes
the chronology of major droughts since the 1920s.
Figure 8: Statewide Drought Levels using SPI Thresholds, 1850 to 2012
Emergency
'3 — Wa rning
WHtcJ L
}
Advisory
a Normal
Source:Massachusetts State Drought Management Plan 2013
>) CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IBC RISK ASSESSMENT 47 of 124
Table 25: Chronology of Major Droughts in Massachusetts
Date Area Affected Recurrence Remarks
Interval (years)
10 to >50 Water-supply sources altered in 13
communities. Multistate.
1929 to 1932 Statewide
15 to >50 More severe in eastern and extreme
western Massachusetts. Multistate.
1957 to 1959 Statewide 5 to 25 Record low water levels in observation
wells, northeastern Massachusetts.
1961 to 1969 Statewide 35 to >50 Water-supply shortages common.
Record drought. Multistate.
Most severe in Ipswich and Taunton
1980 to 1983 Statewide 10 to 30 River basins; minimal effect in Nashua
River basin. Multistate.
Housatonic Duration and severity unknown.
1958 to 1988 River Basin 25 Streamflow showed mixed trends
elsewhere.
Drought declaration began in June
2016 with a Drought Watch which was
2016-2017 Statewide NSA upgraded to a Drought Warning in
August 2016. The Central and
Northeast regions were the most
severely affected.
Drought emergencies have been reached infrequently, with five events occurring in the period between
1 850 and 201 2: 1883, 1911, 1941, 1957, and 1965 to 1966. The drought period between 1965 and
1966 is viewed as the most severe drought to have occurred in modern times in Massachusetts because of
its long duration. On a monthly basis over the 162-year period of record, there is a 1% chance of being in
a drought emergency.
Drought warning levels not associated with drought emergencies have occurred five times, in 1894, 1 91 5,
1930, 1985, and 2016. As of July 2016, a Drought Warning had been declared for the Northeast region,
which includes the Town of Watertown. November 2016 marked the eighth consecutive month of below
average rainfall, and Drought Warnings were extended to the entire state except the Cape and Islands
(see Figure 9).. Conditions returned to normal by April 2017. On a monthly basis over the 1 62-year
period of record, there is a 2% chance of being in a drought warning.
Drought watches not associated with higher levels of drought generally have occurred in three to four
years per decade between 1 850 and 1950. In the 1980s, there was a lengthy drought watch level of
precipitation between 1980 and 1981, followed by a drought warning in 1985. A frequency of drought
watches at a rate of three years per decade resumed in the 1 990s (1995, 1998, and 1999). In the
2000s, drought watches occurred in 2001 and 2002. The overall frequency of being in a drought watch is
8% on a monthly basis over the 162-year period of record.
at CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
1APC RISK ASSESSMENT 48 of 124
Figure 9: Massachusetts Drought Status, December 2016
ti MASSACHUSETTS DROUGHT STATUS IN,
AAs of December 1,2016
weee�
t
sruurrw
w4sln R.'?_ C*rftwut RrvH Rsp6rr GMrel trepan
Drought Levels
Drought Regions
NOTE The MWRA Servrce Area an mdreraua ! srer system has
rCtag Management Plan
&nm u parli;0V wooded morn bor cammum IKnN
Emergency bra sub�"l to regorTal afaughr status
Warning C+ap�tsawn�
WaIV) ,.'� J.
_
i. 'y
Advisory Normal �► �
GiMtM t.��
f e '.e cm ra nn"..ea
6 ry .. '7�I1 �7 �!•ri'Tti aR P�ea tlYMw Awdecea
Source:MA Department of Conservation and Recreation,Office of Water Resources
Under a severe long term drought the Town of Watertown could be vulnerable to restrictions on water
supply. Potential damages of a severe drought could include losses of landscaped areas if outdoor
watering is restricted and potential loss of business revenues if water supplies were severely restricted for
a prolonged period. As this hazard has never occurred to such a severe degree in Watertown, there are
no data or estimates of potential damages, but under a severe long term drought scenario it would be
reasonable to expect a range of potential damages from several hundred thousand to several millions of
dollars. Another potential vulnerability of droughts could be increased risk of wildfires.
However, given the resilience of the MWRA water system due to its very large amount of storage in the
Quabbin and Wachusett Reservoirs (4 billion gallons, which is equivalent to five years of water demand),
severe impacts on the Town are unlikely. For example, even during the multi-year drought of record in
the1960s, there were no severe limitations of supply from the regional water system.
The state has experienced emergency droughts five times between 1850 and 2012. Even though regional
drought conditions may occur at a different interval than state data indicates, droughts remain primarily
regional and state phenomena in Massachusetts. Emergency drought conditions over the 162 period of
record in Massachusetts are a low frequency natural hazard event that can occur from once in 50 years to
once in 100 years (1% to 2% chance per year) as defined by the Massachusetts State Hazard Mitigation
Plan, 2013.
IK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
P APC RISK ASSESSMENT 49 of 124
Impacts of Climate Change
Many of the natural hazards that Watertown has historically experienced are likely to be exacerbated by
climate change in future years. This is particularly true for flooding caused by extreme precipitation and
extreme heat. These are described in more detail below.
Climate Change Impacts: Extreme Precipitation
Watertown's average annual precipitation is 42 inches. While total annual precipitation has not changed
significantly, according to the 2012 report When It Rains It Pours — Global Warming and the Increase in
Extreme Precipitation from 7948 to 207 1 intense rainstorms and snowstorms have become more frequent
and more severe over the last half century in the northeastern United States. Extreme downpours are now
happening 30 percent more often nationwide than in 1948 (see Figure 10). In other words, large rain or
snow storms that happened once every 12 months, on average, in the middle of the 20th century, now
happen every nine months.
Not only are these intense storm events more frequent, they are also more severe: the largest annual
storms now produce 10 percent more precipitation, on average, than in 1948. In particular, the report
finds that New England has experienced the greatest change with intense rain and snow storms occurring
85 percent more often than in 1948.
Recent temperature trends suggest greater potential impacts to come due to climate change. In the report
"Confronting Climate Change in the U.S. Northeast," (2007), the Union of Concerned Scientists presented
temperature projections to 2099 based on two scenarios, one with lower carbon dioxide emissions, and the
other with high emissions.
Climate Change Impacts: Extreme Heat
Between 1961 and 1990, Boston experienced an average of 1 1 days per year over 90°F. That could
triple to 30 days per year by 2095 under the low emissions scenario, and increase to 60 days per year
under the high emissions scenario. Days over 1 00°F could increase from the current average of one day
per year to 6 days with low emissions or 24 days with high emissions. By 2099, Massachusetts could have
a climate similar to Maryland's under the low emissions scenario, and similar to the Carolinas' with high
emissions (see Figure 1 1). Furthermore, the number of days with poor air quality could quadruple in Boston
by the end of the 21 s, century under higher emissions scenario, or increase by half under the lower
emissions scenario. These extreme temperature trends could have significant impacts on public health,
particularly for those individuals with asthma and other respiratory system conditions, which typically affect
the young and the old more severely.
at CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
APC RISK ASSESSMENT 50 of 124
RISK ASSESSMENT
Figure 10 Changes in Frequency of Extreme Downpours, 1948 — 2011
Decrease In Frequency Increase in Frequency�
100ga 09fs -10�6 Iptl6 `+fir IDB%
# # e •
• ios ; • M ■#
s • i ■ • f•
9 * * • 0 •
Source: When It Rains It Pours—Global Warming and the Increase in Extreme
Precipitation, Environment America Research and Policy Center,July 2012
Figure 11 Mass. Extreme Heat Scenarios
r -
1961 ,
x
2010-2039
2040-2069
2070-2099
2
20 20"
Higher-Emission Scenario
Lower-Emission Scenario
Al
Source: Union of Concerned Scientists
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
RISK ASSESSMENT 51 of 124
LAND USE AND DEVELOPMENT TRENDS
EXISTING LAND USE
The most recent land use statistics available from the state are from aerial photography done in 2005.
Change has certainly occurred in Watertown since then, but this data still provides the most detailed
description of Land Use available. Table 26 shows the acreage and percentage of land use in 17
categories. If the two residential categories are aggregated, residential uses make up 51.5% of the area
of the town (1,360 acres). Commercial and industrial combined make up 21.7% of the town, or 572 acres.
Recreation (parks, playing fields) and golf courses comprise another 7% , orl 84 acres, and several
categories of open space combined (forest, forested wetlands, wetlands, crop land, urban public, urban
open, and water) make up 1 1.4% of the town, or 301 acres.
Fable 26: Town of Watertown, MA 2005 Land Lf-
Land Use Acres % of Town
Crop Land (1) 21.3516 0.81%
Forest (3) 61.3060 2.32%
Wetland (4) 6.4152 0.24%
Participation Recreation (7) 100.8173 3.82%
Multi-Family Residential (10) 857.1564 32.48%
High Density Residential (11) 502.7954 19.05%
Salt Water Wetland (14) 0.0000 0.00%
Commercial (15) 408.7280 15.49%
Industrial (16) 163.9892 6.21%
Urban Open (17) 2.4282 0.09%
Transportation (18) 11.5978 0.44%
Water(20) 78.5200 2.98%
Golf Course (26) 83.6821 3.17%
Marina (29) 5.6353 0.21%
Urban Public (31) 126.5023 4.79%
Cemetery(34) 203.2636 7.70%
Forested Wetland (37) 4.6617 0.18%
TOTAL ACRES 2638.8501 100.00%
For more information on how the land use statistics were developed and the definitions of the categories,
please go to httr)s://docs.diaital.mass.aov/dataset/massais-data-1 and-use-2005.
Economic Elements
Much of the Town's economic activity is concentrated on Arsenal Street, in Watertown Square, and along a
few other commercial corridors. The Arsenal Mall, a 225,000 square foot redevelopment, opened in 1983.
The remainder of the historic Watertown Arsenal buildings were converted to civilian uses in 1995, and is
now a commercial and office complex known as the Arsenal on the Charles. There are several
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
1APC RISK ASSESSMENT 52 of 124
redevelopment projects moving through the permitting process along the Arsenal Street corridor that can
transform the area. Two formerly industrial areas, Pleasant Street and Coolidge Hill, have evolved over
time. Pleasant Street now has a mix of industrial, wholesale, office, research and development, and
multifamily housing developments along its corridor. Coolidge Hill is primarily a residential and
neighborhood retail area, with some manufacturing still located there.
The median household income in Watertown was $74,081 in 2010. This represents a 24% increase from
$59,764 in 2000, after being adjusted for inflation. Watertown's median household income is 14.8%
above the state median income. About 7.5% of families were considered below the poverty line.
Watertown has a labor force of about 20,125. In 2010, Watertown had 1,103 industries. Of these, the
largest employment sectors included "Professional and Business Services" (22.1%) and "Trade,
Transportation and Utilities" (1 8.5%). These two sectors comprised 40.6% of the employment in the Town.
Other proportionately large employment sectors include "Education and Health Services" (15.9%),
"Financial Activities" (10.5%), and "Information" (10.2%). Manufacturing, at one point one of the highest,
hass continually decreased over the years and in 2010 was only the 7th highest employment sector (5.4%).
(Narrative from the Watertown Open Space and Recreation Plan 2075).
NATURAL, CULTURAL, AND HISTORIC RESOURCE AREAS
Founded in 1630, Watertown has been described as the "mother town" as it was one of America's earliest
colonial settlements and served as an entry into the heartland of America for early settlers. These early
arrivals to the "New World" were welcomed by Native Americans of the Pequossette Tribe, who had a
long-established tribal network strategically situated to access the natural bounties of the Charles River.
Early colonial accounts of the area describe the abundance of bass, salmon, and herring making their way
to and from the sea for spawning.
During the past 300 years, the Charles River along its length changed from a bountiful aquatic habitat to a
polluted waterway, damaged by former use as an open sewer for industrial and human wastes. It was
reborn as a "water parkway" in the late 1890's only to decline in the mid-201" century and then be
rediscovered as a regional recreational asset. The river has begun to rebound with aquatic life, improved
water quality, and a significant return of recreational activities. Additionally, the Department of
Conservation and Recreation (DCR) continues to make improvements to the Charles River Reservation land
that enhances open space and recreational opportunities for Watertown's residents and visitors.
Watertown's open space system is closely linked to the larger regional system of open space and natural
areas of its neighboring communities. The Charles River links Watertown ecologically and recreationally
with Cambridge and Boston to the east and with up-stream communities such as Waltham, Newton,
Weston, Wellesley, Needham and beyond. Watertown's open space network is particularly closely
connected with Cambridge where the two communities share another significant regional landmark, the Mt.
Auburn Cemetery as a semi-public open space. Approximately 164 acres of the 175-acre Mt. Auburn
Cemetery are in Watertown, making it the largest contiguous open space in Watertown. Narrative from
the Watertown Open Space and Recreation Plan 2075).
lK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 53 of 124
DEVELOPMENT TRENDS
MAPC's MassBuilds database includes 29 new developments in Watertown since 2008. As the town is built
out, most of these projects are on redevelopment sites. As redevelopment occurs it is subject to the latest
building code requirements and zoning regulations pertaining to floodplains, wind, and earthquakes. The
database (Table 27) includes attributes of the new development, including housing units and commercial
space. The 29 new developments in Watertown include a total of 2,142 housing units and more than 1
million square feet of commercial space.
Table 27: Summary of Watertown Developments, 2008-2017
Name Status Year Housing Commercial Flood Zone
Units Square Feet
175 N. Beacon St.-Perkins School Completed 2011 55000 No
480 Arsenal (Linx) Construction 2017 185595 No
Archstone Apartments Completed 2001 134 No
Arsenal Yards Planning 2019 503 380000 No
Arsenal on the Charles 2018 263000 No
32 Church St Panning 2018 5 No
590 Main Street Completed 2010 14 No
Watertown Mews Completed 2008 179 No
24-26 Arsenal Street Completed 2011 14 No
Bell Tower Place Completed 2009 9 No
First Baptist Completed 2009 14 No
Nally Estates Completed 2010 18 No
Towards Independent Living Completed 2011 7800 No
Grousebeck Center-Perkins School Completed 2011 15200 No
Charlesbank Residences Completed 2012 44 No
Riverbend Completed 2013 135 AE: 1% Annual
Chance; with BFE
Part of Riverbend Completed 2013 35 X: 0.2% Annual
Chance of Flooding
Repton Completed 2013 206 No
Bell Watertown Completed 2013 155 No
9 Winter Street Completed 2011 3 No
River Park Lofts Completed 2015 65 10394 No
192 Pleasant St Completed 2014 7 AE: 1% Annual
Chance; with BFE
The Gables Completed 2015 296 6777 No
33 Mt Auburn Planning 2019 24 2115 No
Union Market Construction 2016 282 10600 No
Central Rock Gym Completed 2012 No
65 Grove Street(Old Ionics Bldg.) Construction 2017 1493 No
CVS Pharmacy Construction 2017 14000 No
Marriott Hotel Completed 2016 105652 No
TOTAL 2,142 1,065,426
SCCITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
M PC RISK ASSESSMENT 54 of 124
In order to characterize any change in the town's vulnerability associated with new developments, a GIS
mapping analysis was conducted which overlaid the development sites with the FEMA Flood Insurance Rate
Map. The analysis shows that two of the 30 developments are partially within an AE zone, 0.1% chance of
flooding (100-year), and one of them is also partially within an X zone, 0.2% Annual Chance of flooding
(500 Year). Typically these are portions of a site that are not built out, and at a minimum comply with the
Town's Floodplain regulations.
With respect to other hazard categories, there is no geographic variation across the Town of Watertown.
All developments are within the zone of low incidence for landslides and the zone of 48 to 72 inches
average annual snowfall. The entire town is in the zone of 100-year wind maximum speed of 110 miles
per hour. Overall, Watertown's new development does not significantly increase the town's vulnerability to
natural hazards.
POTENTIAL FUTURE DEVELOPMENT
MAPC consulted with the Local Hazard Mitigation Planning Team to determine areas that may be
developed in the future, based on the Town's comprehensive planning efforts and current trends and
projects. The Town identified 18 potential new development sites, which are listed in Table 28 and shown
on Map 8 in Appendix B.
In order to characterize any change in the town's vulnerability associated with new developments, a GIS
mapping analysis was conducted which overlaid the development sites with the FEMA Flood Insurance Rate
Map. The analysis shows that four of the sixteen sites are partially located in flood zones, typically a
portion of the site that is not built on.
With respect to landslide risk, all of the development sites are located in the area designated as "Low
Incidence" for landslides. As mentioned above, other hazards such as wind speed and snowfall rates do
not vary across the Town of Watertown. None of the potential development sites coincide with hazard
areas identified by the local team. (See hazard maps in Appendix C). Overall, Watertown's potential
future development would not significantly increasing the town's vulnerability.
Table 28: Relationship of Potential Development to Hazard Areas
Map ID Potential Future Project Flood Zones
A Hartz Mason 78.34% in AE: 1% Annual Chance of Flooding, with BFE , and
16.0% in X: 0.2% Annual Chance of Flooding
B Boston Scientific 55.45% in AE: 1% Annual Chance of Flooding, with BFE , and
16.92% in X: 0.2% Annual Chance of Flooding
C Repton Phase II
D Port Oil / Mount Auburn St
E Perkins School
E Perkins School
�F Gore Property
qK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 55 of 124
G 140 Pleasant St 4.6% in X: 0.2% Annual Chance of Flooding
H Ionics
I Greenhouse
J Athena Campus
K Arsenal Yards
L 330 Pleasant 29.48% in AE: 1% Annual Chance of Flooding, with BFE , and
65.89% in X: 0.2% Annual Chance of Flooding
M 385 Pleasant St.
N Marriott Inn Hotel
O 100 N. Beacon
P Elan, Arsenal St. and Irving St.
Q Howard Bacon
CRITICAL FACILITIES & INFRASTRUCTURE IN HAZARD AREAS
Critical facilities and infrastructure includes facilities that are important for disaster response and
evacuation (such as emergency operations centers, fire stations, water pump stations, etc.) and facilities
where additional assistance might be needed during an emergency (such as nursing homes, elderly housing,
day care centers, etc.). There are 82 facilities identified in Watertown. These are listed in Table 29 and
are shown on the maps in Appendix B.
Explanation of Columns in Table 29
• Column 1:ID #:The first column in Table 29 is an ID number which appears on the maps that are part of this
plan. See Appendix B.
• Column 2:Name: The second column is the name of the site. If no name appears in this column,this information
was not provided to MAPC by the community.
• Column 3: Type: The third column indicates what type of site it is.
• Column 4:FEMA Flood Zone: The fourth column addresses the risk of flooding. A "No" entry in this column
means that the site is not within any of the mapped risk zones on the Flood Insurance Rate Maps (FIRM maps).
If there is an entry in this column, it indicates the type of flood zone. as follows:
Zone AE (1% annual chance) - Zones AE is the flood insurance rate zone that correspond to the 100-year
floodplains that are determined in the FIS by detailed methods. In most instances, BFEs derived from the
detailed hydraulic analyses are shown at selected intervals within this zone. Mandatory flood insurance
purchase requirements apply.
Zone X: Ares of 0.2% annual chance of flood.
Floodway: The channel of a stream plus any adjacent floodplain areas that must be kept free of
encroachment so that the 1% annual chance flood can be carried without substantial increases in flood
heights.
• Column 5:Locally-Identified Area of Flooding: The fifth column indicates the risk of flooding in local hazard
areas. A "No" entry in this column means that the site is not within any of the mapped flood hazard zones. If
there is an entry in this column, it indicates the local hazard area.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IVIAPC RISK ASSESSMENT 56 of 124
Table 29: Critical Facilities and Relationship to Hazard Areas
FEMA Flood Locally-
ID Name Type Zone Identified
Flood Area
1 Watertown Town Hall Municipal No No
2 Watertown Health Department Municipal No No
3 Watertown Police Department Police Station No No
Emergency
4 EOC-Secondary Fire HQ Operations No No
Center
5 Fire Department#2 Fire Station No No
6 Fire Department HQ Fire Station No No
7 Fire Department#3 Fire Station No No
8 Harvard Vanguard Medical Facility Medical Facility No No
Associates
9 Caritas Medical Facility Group at Watertown Medical Facility No No
10 St. Elizabeth's Caritas Clinic Medical Facility No No
11 Dr. Richard J. Kerbel Medical Facility No No
12 Dr. Aida M. Yayshayan Medical Facility No No
13 Milestones Child Care & Preschool Child Care No No
14 Bright Horizons on the Charles Child Care No No
15 Caterpillars to Butterflies Child Care No No
16 First Path Day Care Center Child Care No No
17 Four Seasons Preschool Child Care No No
18 Watertown Integrated Pre-School Child Care No No
19 Russell Cooperative Preschool Child Care No No
20 St. Stephens Armenian Preschool Child Care No No
21 Stepping Stones Child Care Center, Inc. Child Care No No
22 Storyville Preschool Child Care No No
23 Watertown Cooperative Nursery School Child Care No No
24 Watertown Creative Start Child Care No No
25 Watertown Dam Dam AE: 1% Annual No
Chance
26 Watertown High School School No Yes
27 James Russell Lowell Elementary School School No No
28 Cunniff Elementary School School No Yes
29 Hosmer Elementary School School No No
30 Jewish Community Day School School No No
31 Perkins School for the Blind School No No
32 Atrium School School No No
33 St Stephen's Armenian School School No No
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
P APC RISK ASSESSMENT 57 of 124
FEMA Flood Locally-
ID Name Type Identified
Zone Flood Area
34 Beacon High School School No No
35 Watertown Middle School School No No
36 James Russell Lowell School - EDS Emergency No No
Distribution Site
37 St Stephen's Armenian Cultural Center Church No No
38 Brigham House Assisted Living No No
39 Commander's Mansion - Secondary EDS Emergency No No
Distribution Site
40 John A Ryan Arena Place of Assembly No No
41 Watertown Senior Center Senior Center No No
42 Watertown Boys and Girls Club Place of Assembly No No
43 Watertown School Department Offices Municipal No No
Communication
44 Verizon Switching Station No No
Tower
Communication
45 Police-Fire Main Repeaters No No
Tower
46 U.S. Post Office Post Office No No
47 U.S. Post Office Post Office No No
48 U.S. Post Office Post Office No No
49 Marshall Home Assisted Living No No
50 NStar Power Station Power Substation No No
51 NSTar Power Station Power Substation No No
52 MBTA Power Station Power Substation No No
53 MWRA Water Meter#40 MWRA No No
54 Saint John's Methodist Church Church No No
55 MWRA Meter#2 MWRA No No
56 MWRA Water Meter#103 MWRA No No
57 MWRA Water Meter#92 MWRA No No
58 MWRA Water Isolation Valve MWRA No No
59 Watertown Free Public Library Municipal No No
60 Arsenal Apartment Elder Housing Elder Housing No No
61 Watertown Elder Housing Elder Housing No No
62 McSherry Gardens Elder Housing No No
63 100 Warren Street Elder Housing Elder Housing No No
64 Emergency Water Connection Belmont Water Connection No No
65 Emergency Water Connection Belmont Water Connection No No
66 Emergency Water Connection Newton Water Connection No No
67 Emergency Water Connection Waltham Water Connection No No
68 Emergency Water Connection Waltham Water Connection No No
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 58 of 124
FEMA Flood Locally-
ID Name Type Identified
Zone Flood Area
69 Emergency Water Connection Waltham Water Connection No No
70 Emergency Water Connection Waltham Water Connection No No
71 Clinic - Partners Urgent Care Medical Facility No No
72 Watertown Health Center Nursing Home No No
73 Coolidge Hill Radio Antenna Communications No No
74 Coolidge School Apartments Senior Housing No No
75 MBTA Transit Hub Transportation No No
76 Residence Residences No No
77 AFC Urgent Clinic Medical Facility No No
78 Circle of Boston Nursery School Daycare No No
79 Strawberry Childcare Daycare No No
80 First Step Child Care Center Daycare No No
81 Open Wings Child Care Center Daycare No No
82 Early Steps Watertown Pre-school Daycare No No
With respect to the location of Critical Facilities in hazard zones, only one site, the Watertown Dam, is
located within a FEMA Flood zone, AE, 1% Annual Chance of flooding. This would be expected as by
definition any dam is located within the floodplain of a river or stream.
Two of the sites, Watertown High School and Cunniff Elementary School, were identified by the Town as
areas of local concern for flooding due to basement flooding from high groundwater (see Table 8).
All the Towns Critical Facilities are located within an area designated as "low incidence" for landslides,
and average annual snowfall of 48 to 72 inches. All are also within the area of 100-year wind speeds of
1 10 miles per hour, as these hazards are the same across the entire town.
tt CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 59 of 124
VULNERABILITY ASSESSMENT
The purpose of the vulnerability assessment is to estimate the extent of potential damages from natural
hazards of varying types and intensities. A vulnerability assessment and estimation of damages was
performed for hurricanes, earthquakes, and flooding through the HAZUS-MH software.
Introduction to HAZUS-MH
HAZUS- MH (multiple-hazards) is a computer program developed by FEMA to estimate losses due to a
variety of natural hazards. The following overview of HAZUS-MH is taken from the FEMA website. For
more information on the HAZUS-MH software, go to
http://www.fema.aov/plan/prevent/hazus/index.shtm
"HAZUS-MH is a nationally applicable standardized methodology and software program that
contains models for estimating potential losses from earthquakes, floods, and hurricane winds.
HAZUS-MH was developed by the Federal Emergency Management Agency (FEMA) under contract
with the National Institute of Building Sciences (NIBS). Loss estimates produced by HAZUS-MH are
based on current scientific and engineering knowledge of the effects of hurricane winds, floods and
earthquakes. Estimating losses is essential to decision-making at all levels of government, providing
a basis for developing and evaluating mitigation plans and policies as well as emergency
preparedness, response and recovery planning.
HAZUS-MH uses state-of-the-art geographic information system (GIS) software to map and display
hazard data and the results of damage and economic loss estimates for buildings and
infrastructure. It also allows users to estimate the impacts of hurricane winds, floods and
earthquakes on populations."
There are three modules included with the HAZUS-MH software: hurricane wind, flooding, and
earthquakes. There are also three levels at which HAZUS-MH can be run. Level 1 uses national baseline
data and is the quickest way to begin the risk assessment process. The analysis that follows was completed
using Level 1 data. Level 1 relies upon default data on building types, utilities, transportation, etc. from
national databases as well as census data. While the databases include a wealth of information on the
Town of Watertown, it does not capture all relevant information. In fact, the HAZUS training manual notes
that the default data is "subject to a great deal of uncertainty."
However, for the purposes of this plan, the analysis is useful. This plan is attempting to generally indicate
the possible extent of damages due to certain types of natural disasters and to allow for a comparison
between different types of disasters. Therefore, this analysis should be considered to be a starting point
for understanding potential damages from the hazards.
JK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
PC RISK ASSESSMENT 60 of 124
ESTIMATED DAMAGES FROM HURRICANES
The HAZUS software was used to model potential damages to the community from a 100-year and 500-
year hurricane event; storms that are 1% and 0.2% likely to happen in a given year, and roughly
equivalent to a Category 2 and Category 4 hurricane. The damages caused by these hypothetical storms
were modeled as if the storm track passed directly through the town, bringing the strongest winds and
greatest damage potential.
Though there are no recorded instances of a hurricane equivalent to a 500-year storm passing through
Massachusetts, this model was included in order to present a reasonable "worst case scenario" that would
help planners and emergency personnel evaluate the impacts of storms that might be more likely in the
future, as we enter into a period of more intense and frequent storms.
Table 30: Estimated Damages from Hurricanes
100-Year 500-Year
Building Characteristics
Estimated total number of buildings 9,836
Estimated total building replacement value (2014 $) $4,852,000,000
Building Damages
# of buildings sustaining minor damage 321 1,667
# of buildings sustaining moderate damage 39 360
# of buildings sustaining severe damage 2 27
# of buildings destroyed 0 6
Population Needs
# of households displaced 1 63
# of people seeking public shelter 0 6
Debris
Building debris generated (tons) 2,719 11,747
Tree debris generated (tons) 1,136 3,231
# of truckloads of building debris (@25 tons/truck) 109 470
Value of Damages
Property damage (buildings and content) $23,315,020 $101,801,000
Losses due to business interruption $1,456,000 $10,725,000
Total Losses $24,771,020 $112,526,000
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
APC RISK ASSESSMENT 61 of 124
ESTIMATED DAMAGES FROM EARTHQUAKES
The HAZUS earthquake module allows users to define an earthquake magnitude and model the potential
damages caused by that earthquake as if its epicenter had been at the geographic center of the study
area. For the purposes of this plan, two earthquakes were selected: magnitude 5.0 and a magnitude 7.0.
Historically, major earthquakes are rare in New England, though a magnitude 5 event occurred in 1963.
Table 31: Estimated Damages from Earthquakes
Magnitude 5.0 Magnitude 7.0
Building Characteristics
Estimated total number of buildings 9,836
Estimated total building replacement value (2014 $) $4,852,000,000
Building Damages
# of buildings sustaining slight damage 2,752 470
# of buildings sustaining moderate damage 1,781 2,051
# of buildings sustaining extensive damage 640 2,348
# of buildings completely damaged 184 4,410
Population Needs
# of households displaced 1,137 9,876
# of people seeking public shelter 505 2,324
Debris
Building debris generated (tons) 175,000 1,167,000
# of truckloads to clear debris (@ 25 tons/truck) 7,000 46,680
Value of Damages
Property damage $770,490,000 $4,363,566,300
Losses due to business interruption $120,548,400 $629,104,500
Total Losses $891,038,400 $4,992,670,800
Figure 12 Watertown Magnitude 7 Earthquake Losses by Occupancy Type
1BOO
1601) Single
1401) Family
1201) Other
Residential
10OD
801) Gornmercial
1001)
401) —
�.'t'1
2OD — — —
1) — — — —
Source: HAZUS for Watertown.MA. 500-Year Riverine Flood Scenario
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC RISK ASSESSMENT 62 of 124
ESTIMATED DAMAGES FROM FLOODING
The HAZUS flooding module allows users model the potential damages caused by a 100-year flood event
and a 500-year flood event.
Table 32: Estimated Damages from Flooding
100-Year Flood 500-Year Flood
Building Characteristics
Estimated total number of buildings 9,836
Estimated total building replacement value (2014 $) $4,853,000,000
Building Damages
# of buildings sustaining moderate damage 2 5
# of buildings sustaining extensive damage 0 1
# of buildings substantially damaged 0 0
Population Needs
# of households displaced 84 162
# of people seeking public shelter 4 6
Value of Damages
Total property damage $24,690,000 $37,240,000
Total losses due to business interruption $20,960,000 $31,900,000
Total Losses $45,650,000 $69,140,000
Figure 13: Watertown 500-Year Flood Losses by Occupancy Type
� Resldcr�tlal
CCMM cRhl S61
hiziml ill
0aff ii
7aWt 359
Source: HAZUS for Watertown.MA.500-Year Riverine Flood Scenario
14 CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
f APC RISK ASSESSMENT 63 of 124
[This page intentionally left blank]
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
RISK ASSESSMENT 64 of 124
SECTION • , •
GOALS
The Watertown Local Hazard Mitiagation Team reviewed and discussed the of hazard mitigation goals for
the Town of Watertown. The following nine goals were endorsed by the team for this Watertown Hazard
Mitigation Plan 2019 Update:
1. Prevent and reduce the loss of life, injury, public health impacts and property damages resulting
from all major natural hazards.
2. Identify and seek funding for measures to mitigate or eliminate each known significant flood
hazard area.
3. Integrate hazard mitigation planning as an integral factor in all relevant municipal departments,
committees and boards.
4. Prevent and reduce the damage to public infrastructure resulting from all hazards.
5. Encourage the business community, major institutions and non-profits to work with the Town to
develop, review and implement the hazard mitigation plan.
6. Work with surrounding communities, state, regional and federal agencies to ensure regional
cooperation and solutions for hazards affecting multiple communities.
7. Ensure that future development meets federal, state and local standards for preventing and
reducing the impacts of natural hazards.
8. Take maximum advantage of resources from FEMA and MEMA to educate Town staff and the
public about hazard mitigation.
9. Consider the impacts of climate change and incorporate climate sustainability and resiliency into
hazard mitigation and other Town plans and policies.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
ApC HAZARD MITIGATION GOALS 65 of 124
[This page intentionally left blank]
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
HAZARD MITIGATION GOALS 66 of 124
6: EXISTING MITIGATION
L SECTION
MEASURE
The existing protections in the Town of Watertown are a combination of zoning, land use, and
environmental regulations, infrastructure maintenance, and drainage infrastructure improvement projects.
Infrastructure maintenance generally addresses localized drainage clogging problems, while large scale
capacity problems may require pipe replacement or invert elevation modifications. These more expensive
projects are subject to the capital budget process.
The Towns existing mitigation measures, which were in place prior to the original 2012 Plan, are listed by
hazard type here and are summarized in Table 33 below. Many upgrades to existing measures are
noted in the following sections.
EXISTING TOWN-WIDE MITIGATION FOR FLOOD-RELATED HAZARDS
Watertown employs a number of practices to help minimize potential flooding and impacts from flooding,
and to maintain existing drainage infrastructure. Existing town-wide mitigation measures include the
following:
Participation in the National Flood Insurance Program (NFIP) — Watertown participates in the NFIP with 91
policies in force as of the September 30, 2018. FEMA maintains a database on flood insurance policies
and claims. This database can be found on the FEMA website at httDs://www.fema.aov/policy_ -claim-
statistics-flood-insurance
The following information is provided for the Town of Watertown:
Flood insurance policies in force (September 30, 201 8) 91
Coverage amount of flood insurance policies $25,440,100
Premiums paid $51,569
Total losses (all losses submitted regardless of the status) 18
Closed losses (losses that have been paid) 13
Open losses (losses that have not been paid in full) 0
CWOP losses (losses that have been closed without payment) 5
Total payments (total amount paid on losses) $788,689.62
The Town complies with the NFIP by enforcing floodplain regulations, maintaining up-to-date floodplain maps,
and providing information to property owners and builders regarding floodplains and building requirements.
Street sweeping — Every street gets swept at least four times a year with the Town completing on average
16 curb miles a week.
Catch basin cleaning — The town has approximately 3200 catch basins that are cleaned every year on
average. This service is contracted out by the town.
Roadway treatments — The Town uses liquid calcium salt additive.
S, CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 67 of 124
Drainage infrastructure maintenance - The town requires a maintenance agreement in perpetuity on private
drainage facilities. To the extent possible, the Town requires all storm water to be handled on site rather
than directed into the municipal storm drain system.
Zoning Regulations— Zoning is intended to protect the public health and safety through the regulation of
land use. The Watertown Zoning Ordinance includes a Floodplain District (Section 5.06). The purposes of
this district are to:
1. To provide that lands in the Town of Watertown subject to seasonal or periodic flooding as
described hereinafter shall not be used for residence or other purposes in such manner as to
endanger the health or safety of the occupants thereof.
2. To protect, preserve and maintain the water table and water recharge areas within the Town so as
to preserve the present and potential water supplies for the public health and safety of the
residents of the Town of Watertown.
3. To assure the continuation of the natural flow pattern of the water courses within the Town of
Watertown in order to provide adequate and safe floodwater storage capacity to protect persons
and property against the hazards of flood inundation.
The Floodplain District is an overlay district, defined by the 100-year floodplain as designated by FEMA.
Within the District, by-right uses are limited to conservation, outdoor recreation, wildlife preservation,
existing structures, and certain retail uses in the RD — Limited Redevelopment District which meet criteria
established within the Floodplain District and have been issued a final Order of Conditions under the
Massachusetts Wetlands Protection Act. An existing structure may be expanded and other uses, as
allowed in the underlying zoning district, may be allowed by Special Permit, providing that it can be
demonstrated that the proposed construction will not be detrimental to the public health, safety, or
welfare, and the project meets the requirements of all applicable state and local regulations including
those of the Massachusetts State Building Code pertaining to buildings within the floodplain.
Stormwater Ordinance —A storm water ordinance is has been adopted to help the Town comply with the
MS4 Stormwater Permit issued by EPA. The Ordinance requires stormwater retention up to the 100-year
storm for new development
Wetlands Ordinance - The Town of Watertown Wetlands Ordinance (Chapter XV) protects water
resources, wetlands, and their adjoining land areas by controlling activities that might have a significant or
cumulative impact on the recognized values of these resource areas, including their ability to serve as a
flood control and storm damage prevention feature. Any activity that might fill or otherwise alter these
resource areas requires a permit from the Watertown Conservation Commission. The adjoining land area
under the protection of this by-law includes land within 150 feet of a pond or wetland and land within
200 feet of a river or stream as well as any land within a designated floodplain.
Watertown Open Space and Recreation Plan (OSRP) - Watertown's OSRP was updated in 2015 and
identifies a number of open space parcels in identified hazard areas including floodplains and brush fire
areas. For many of these parcels the plan recommends developing use and management plans, including
lands along the Charles River and Whitney Hill. These management plans should include consideration of
hazard issues such as flooding and brush fires.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 68 of 124
EXISTING DAM MITIGATION MEASURES
DCR dam safety regulations — The state has enacted dam safety regulations mandating inspections and
emergency action plans. All new dams are subject to state permitting.
Watertown Dam: An Emergency Action Plan (EAP) was completed in July 2018 by the MA Department of
Conservation and Recreation (DCR), which owns and operates this dam on the Charles River near
Watertown Square. The plan includes emergency notification procedures, a general response flowchart, an
impact summary and mapping, and sections on preparedness, emergency detection, evaluation, and
classification. A section on general responsibilities describes the roles of DCR, MEMA, the State Police, and
the local police and fire departments.
In addition, Emergency Action Plans have been completed for several upstream dams outside of
Watertown that could have an impact on the town if they failed. These include
• Cambridge Reservoir Dam and Stony Brook Reservoir Dam, located in Waltham and Weston, owned
and operated by the City of Cambridge Water Department. These reservoirs on tributaries of the
Charles River are the principal sources of public water supply for the city of Cambridge.
• Norumbega and Schenck's Pond Dams in Weston, both owned and operated by the Massachusetts
Water Resources Authority as part of the MWRA regional water distribution system.
• Weston Reservoir Dam, also owned by the MWRA as part of the regional water distribution system.
In March 2018 the Watertown Fire Department attended Emergency Action Plan training for Weston
Reservoir Dam and Norumbega Reservoir Dams/Schenck's Pond Dam in Weston MA. This training was
conducted by Christine E. Suhonen, P.E. from GZA and administered by the MWRA.
EXISTING TOWN-WIDE MITIGATION FOR WIND-RELATED HAZARDS
Massachusetts State Building Code — The town enforces the Massachusetts State Building Code whose
provisions are generally adequate to protect against most wind damage. The code's provisions are the
most cost-effective mitigation measure against tornados given the extremely low probability of occurrence.
If a tornado were to occur, the potential for severe damages would be extremely high.
Tree-trimming program — The Town conducts its own tree maintenance and also uses its own equipment to
trim and remove trees as needed and grind stumps.
EXISTING TOWN-WIDE MITIGATION FOR WINTER-RELATED HAZARDS
Snow disposal —The town conducts general snow removal operations with its own equipment. There is a
park on grove street that is used a snow disposal site as necessary.
EXISTING TOWN-WIDE MITIGATION FOR FIRE-RELATED HAZARDS
Outdoor Burning Prohibited— Outdoor burning is prohibited in Watertown.
Development Review— The Fire Department is a member of the site plan review committee.
S, CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
i'''}APC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 69 of 124
EXISTING TOWN-WIDE MITIGATION FOR GEOLOGIC HAZARDS
Massachusetts State Building Code — The State Building Code contains a section on designing for
earthquake loads (780 CMR 1612.0). Section 1 61 2.1 states that the purpose of these provisions is "to
minimize the hazard to life to occupants of all buildings and non-building structures, to increase the
expected performance of higher occupancy structures as compared to ordinary structures, and to improve
the capability of essential facilities to function during and after an earthquake". This section goes on to
state that due to the complexity of seismic design, the criteria presented are the minimum considered to be
"prudent and economically justified" for the protection of life safety. The code also states that absolute
safety and prevention of damage, even in an earthquake event with a reasonable probability of
occurrence, cannot be achieved economically for most buildings.
Section 161 2.2.5 sets up seismic hazard exposure groups and assigns all buildings to one of these groups
according to a Table 161 2.2.5. Group II includes buildings which have a substantial public hazard due to
occupancy or use and Group III are those buildings having essential facilities which are required for post-
earthquake recovery, including fire, rescue and police stations, emergency rooms, power-generating
facilities, and communications facilities.
EXISTING MULTI-HAZARD MITIGATION MEASURES
Comprehensive Emergency Management Plan (CEMP) — Every community in Massachusetts is required to
have a Comprehensive Emergency Management Plan. These plans address mitigation, preparedness,
response and recovery from a variety of natural and man-made emergencies. These plans contain
important information regarding flooding, hurricanes, tornadoes, dam failures, earthquakes, and winter
storms. Therefore, the CEMP is a mitigation measure that is relevant to all of the hazards discussed in this
plan.
Communications Equipment — The Town has access to three Incident Command Units, mobile communications
centers available to the town through the MA State Police, the MA Dept. of Fire Services, and MEMA.
Improvements to the communications system are being pursued by the Town (see Section 8).
Emergency Power Generators — Emergency generators are located at the Town Hall, Main Library, Police
Department, Fire Department, Public Works Facility, and Watertown High School. The town is planning to
install additional generators in schools (See Section 8).
Massachusetts State Building Code — The Massachusetts State Building Code contains many detailed
regulations regarding wind loads, earthquake resistant design, flood-proofing, and snow loads.
S, CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
P" APC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 70 of 124
COMPILATION OF EXISTING MITIGATION
Table 33 summarizes the existing natural hazard mitigation measures already in place in Watertown.
Table 33: Existing Natural Hazard Mitigation measures in Waterrown
Type of Existing Mitigation Area Effectiveness/ Improvements/
Measures Covered Enforcement Changes Needed
MULTIPLE HAZARDS
Comprehensive Emergency Town-wide. Emphasis is on Currently up to
Management Plan (CEMP) emergency date. Needs to be
response. periodically update
Communications Equipment Town-wide. Improvements are The Town is
being implemented pursuing upgrades
by the town. for integrated
communications
among Police, Fire,
and Public Works
Massachusetts State Town-wide. Most effective for None.
Building Code new construction.
Participation in the Town-wide. A forum for The Battle Road
Regional Emergency cooperation on Emergency Planning
Planning Committee natural and Comm. disbanded.
(disbanded since the manmade disasters. The Town is
previous plan) considering other
options for this.
Emergency Power Town-wide. Improvements are The Town is
Generators being implemented pursuing generators
by the town. for schools
FLOOD HAZARDS
Participation in the National Areas identified on the FIRM There are 91 Encourage all
Flood Insurance Program maps. policies in force. eligible
(NFIP). The Town actively FIRM map date homeowners to
enforces the floodplain 2010 (not updated obtain insurance.
regulations. since 2012 plan)
Street sweeping Town-wide. Effective. MS4 Permit may
require changes
Catch basin cleaning Town-wide. Effective. MS4 Permit may
require changes
Roadway treatments Town roads. Effective. None.
Drainage infrastructure Town-wide. Effective Ongoing
maintenance maintenance
needed
Zoning — Floodplain District Town-wide. Effective. None
1 CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 71 of 124
Stormwater Ordinance Town-wide. Effective MS4 Permit may
require changes
Wetlands Protection Wetland Resource Areas Effective None
Ordinance
Watertown OSRP Town-wide Effective The OSRP was
updated in 2015
DAM HAZARDS
DCR dam safety regulations State-wide. Somewhat effective Improvements to the
and permitting statewide system
for dam inspections.
Emergency Action Plans Charles River floodplain areas Effective Plans were recently
(EAP) have been prepared completed and are
for the Watertown Dam, up to date
Cambridge Reservoir and
Stony Brook Dams, Weston
Dam, and the Norumbega
and Schenck's Pond Dams
Watertown Fire Dept Charles River floodplain areas Effective None; continue to
attended EAP training for participate in any
Weston Reservoir Dam and future dam trainings
Norumbega Reservoir
Dams/Schenck's Pond Dams
WIND HAZARDS
Comprehensive Emergency Town-wide. Effective primarily CEMP is up to date
Management Plan (CEMP) for emergency
response.
The Massachusetts State Town-wide. Effective for most None.
Building Code situations except
severe storms
Tree trimming program Town-wide. Improvements are More capacity for
being implemented tree trimming
by the town. needed
WINTER HAZARDS
Regular salting and sanding Town-wide Effective None
of the roads and local
plowing.
BRUSH FIRE HAZARDS
Outdoor burning Town-wide. Effective. None.
prohibited.
Development Review Town-wide. Effective. None.
GEOLOGIC HAZARDS
The Massachusetts State Town-wide. Effective for most None.
Building Code situations.
St CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAIPC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 72 of 124
MITIGATION CAPABILITIES AND LOCAL CAPACITY FOR IMPLEMENTATION
Under the Massachusetts system of "Home Rule," the Town of Watertown is authorized to adopt and from
time to time amend a number of local bylaws and regulations that support the town's capabilities to
mitigate natural hazards. These include the Zoning Ordinance, Stormwater Ordinance, Subdivision and Site
Plan Review Regulations, Wetlands Ordinance, Health Regulations, Public Works regulations, and local
enforcement of the State Building Code. Local Ordinances may be amended by the Town Council to
improve the town's capabilities, and changes to most regulations simply require a public hearing and a
vote of the authorized board or commission. The Town of Watertown has recognized several existing
mitigation measures that require implementation or improvements, and has the capacity based on these
Home Rule powers within its local boards and departments to address these.
Several Town departments including Public Works and Community Development and Planning will address
planned infrastructure projects. The Department of Public Works will collaborate with state agencies (DCR,
MWRA) on dam management issues. Finally, efforts to improve emergency communications will be a
collaborative effort among the Fire Department, Police Department, and Public Works Department.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 73 of 124
[This page intentionally left blank]
OwCITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 74 of 124
SECTION OF •
MEASURES VROM JHE 2012 PLAN
IMPLEMENTATION PROGRESS ON THE PREVIOUS PLAN
At a meeting of the Watertown Hazard Mitigation Planning Committee, Town staff reviewed the mitigation
measures identified in the 2012 Watertown Hazard Mitigation Plan and determined whether each
measure had been implemented or deferred. Of those measures that had been deferred, the committee
evaluated whether the measure should be deleted or carried forward into this Hazard Mitigation Plan
2019 Update. The decision on whether to delete or retain a particular measure was based on the
committee's assessment of the continued relevance or effectiveness of the measure and whether the
deferral of action on the measure was due to the inability of the Town to take action on the measure.
Table 34 summarizes the status of the mitigation measures.
Table 34: 2019 Status of Mitigation Measures from the 2012 Plan
Mitigation Measure Priority 2019 Status Include in
Completed / In Progress / 2018 Plan
Not Completed Update?
Priority?
High Priority
A) Charles River Maintain coordination High Partially complete: Yes-High
with operators of dams Emergency Action Plans
upstream and (EAP) have been
downstream of completed for Watertown
Watertown Dam in 2018, for the
upstream Norumbega and
Schenck's Pond Dams in
Weston in 2018, and the
upstream Stony Brook and
Hobbs Brook Dams in
Waltham and Weston in
2013
In March 2018 Watertown
Fire Dept. staff attended
Emergency Action Plan
training for the
Norumbega Reservoir
Dam Schenck's Pond Dam
and Weston Reservoir
Dam in Weston
B) Flooding, Continue revising storm High Completed: Stormwater No
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MA PC,- STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 75 of
124
Mitigation Measure Priority 2019 Status Include in
Completed / In Progress / 2018 Plan
Not Completed Update?
Priority?
Drainage water program. Ordinance was adopted
Infrastructure by the Town; requires
and Dams retention of stormwater up
to the 100-year storm.
C) Earthquakes Purchase mobile, long- High Completed No
running generators
and/or install fixed,
multi-fuel generators in
designated emergency
shelters
D) Brush Fire — Build fire access road High Not Completed No
Whitney Hill and create brush fire
prevention program.
E) Brush Fire Purchase a Brush truck. High Not Completed No
F) Multi-hazard Purchase hand-held GPS High Partially completed: The Yes-High
units and mobile radio Town acquired GPS units;
communications they are currently working
equipment on a communications
upgrade to change radio
frequencies for a uniform
single system that will
serve Police, Fire, and
Public Works
G) Multi-hazard: Upgrade all generators High Partially completed: The Yes-High
power outage as needed. Town upgraded 2
generators.
H) Multi-hazard: Install fixed, multi-fuel High Completed No
power outage generators at Town Hall.
1) FIRM mapping Maintain updated town High Partially Completed: Town Yes-High
and bylaws Flood Information Rate staff attended a Charles
Maps (FIRM) maps Watershed Risk Map
information and town workshop sponsored by
ordinance. FEMA in July 2018
Medium Priority
J) Charles River Program to fund and Medium Not completed No
provide technical
assistance for flood
protection.
IK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IVIAPC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 76 of 124
Mitigation Measure Priority 2019 Status Include in
Completed / In Progress / 2018 Plan
Not Completed Update?
Priority?
K) Cunniff Upgrade pumps and Medium Not completed: To be Yes-
Elementary improve site drainage. incorporated into the Medium
School Town's School Building
Program
L) Watertown Upgrade pumps and Medium Not completed: To be Yes-
High School improve site drainage. incorporated into the Medium
Town's School Building
Program
M) Rutland Street Program to fund and Medium Partially completed: Yes-
assist homeowners with Homeowners have more Medium
pumps. pumping capacity.
N) Flooding, Dedicate more resources Medium Completed No
Drainage for more frequent
Infrastructure maintenance of town-
and Dams owned drainage
facilities, such as more
frequent removal of
sediment.
O) Flooding, Study feasibility of Medium Not completed Yes-
Drainage creating stormwater Medium
Infrastructure utility
and Dams
P) Flooding, Develop greater Medium Partially completed: Yes-
Drainage emergency flood Medium
Infrastructure preparation and
and Damsbvg
emergency response
capacity.
Q) High Winds Increase contract labor Medium Partially completed: The Yes-
and Hurricanes for tree maintenance Town has established a Medium
program. Tree Warden Supervisor
under the Dept. of Public
Works
R) Earthquakes Investigate options to Medium Not completed Yes-Low
make all public buildings
earthquake resistant.
S) Multi-hazard Purchase a digital/hard High Completed No
copy map plotter to
enable large map
creation from town GIS
files
St CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IVIAPC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 77 of 124
As indicated in Table 34, the Town completed several mitigation measures include. Adoption of a
Stormwater Ordinance, installation of a fixed generator in Town Hall, initiation of a test program to assist
homeowners with installing pumps, increased capacity for sediment removal in drainage facilities,
acquisition of hand-held GPS units and upgrade of GIS equipment.
Several projects that were not completed will be continued into this plan update. These include installing
backup generators in several schools, implementing the Rutland Street project for pump installations,
increasing capacity for tree maintenance, coordinating dam management with state agencies, and
upgrading the emergency communications system for inter-operability between Fire, Police, and Public
Works. .
Moving forward into the next five-year plan implementation period there will be many more opportunities
to incorporate hazard mitigation into the Town's decision making processes.
Overall, eleven mitigation measures from the 2012 plan will be continued in this 2019plan update. Most
will retain the same priority in this 2019 update. Three measures that were not completed will not be
carried forward into current plan, including the purchase of a brush fire truck, which is not deemed
necessary due to the low frequency of brush fires in the Town.
Moving forward into the next five year plan implementation period there will be many more opportunities
to incorporate hazard mitigation into the Town's decision making processes. The challenges the Town faces
in implementing these measures are primarily due to limited funding and available staff time. This plan
should help the Town prioritize the best use of its limited resources for enhanced mitigation of natural
hazards.
1 CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC STATUS OF MITIGATION MEASURES FROM THE 2012 PLAN 78 of 124
SECTION • • , MITIGATION
STRATEGY
WHAT IS HAZARD MITIGATION?
Hazard mitigation means to permanently reduce or alleviate the losses of life, injuries and property
resulting from natural hazards through long-term strategies. These long-term strategies include planning,
policy changes, education programs, infrastructure projects and other activities. FEMA currently has three
mitigation grant programs: the Hazards Mitigation Grant Program (HGMP), the Pre-Disaster Mitigation
program (PDM), and the Flood Mitigation Assistance (FMA) program. The three links below provide
additional information on these programs.
https://www.fema.gov/hazard-mitigation-g rant-program
https://www.fema.gov/pre-disaster-mitigation-grant-program
https://www.fema.gov/flood-mitigation-assistance-grant-program
Hazard Mitigation Measures can generally be sorted into the following groups:
• Prevention: Government administrative or regulatory actions or processes that influence the way
land and buildings are developed and built. These actions also include public activities to reduce
hazard losses. Examples include planning and zoning, building codes, capital improvement
programs, open space preservation, and stormwater management regulations.
• Property Protection: Actions that involve the modification of existing buildings or infrastructure to
protect them from a hazard or removal from the hazard area. Examples include acquisition,
elevation, relocation, structural retrofits, flood proofing, storm shutters, and shatter resistant glass.
• Public Education & Awareness: Actions to inform and educate citizens, elected officials, and
property owners about the potential risks from hazards and potential ways to mitigate them. Such
actions include outreach projects, real estate disclosure, hazard information centers, and school-age
and adult education programs.
• Natural Resource Protection: Actions that, in addition to minimizing hazard losses also preserve or
restore the functions of natural systems. These actions include sediment and erosion control, stream
corridor restoration, watershed management, forest and vegetation management, and wetland
restoration and preservation.
• Structural Projects: Actions that involve the construction of structures to reduce the impact of a
hazard. Such structures include storm water controls (e.g., culverts), floodwalls, seawalls, retaining
walls, and safe rooms.
• Emergency Services Protection: Actions that will protect emergency services before, during, and
immediately after an occurrence. Examples of these actions include protection of warning system
capability, protection of critical facilities, and protection of emergency response infrastructure.
(Source: FEMA Local Multi-Hazard Mitigation Planning Guidance)
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC HAZARD MITIGATION STRATEGY 79 of 124
REGIONAL AND INTER-COMMUNITY CONSIDERATIONS
Some hazard mitigation issues are strictly local. The problem originates primarily within the municipality
and can be solved at the municipal level. Other issues are inter-community and require cooperation
between two or more municipalities. There is a third level of mitigation which is regional and may involve a
state, regional or federal agency, or three or more municipalities.
REGIONAL PARTNERS
In many communities, mitigating natural hazards, particularly flooding, is more than a local issue. The
drainage systems that serve these communities are complex systems of storm drains, roadway drainage
structures, pump stations, dams, and other facilities owned and operated by a wide array of agencies
including the Town, Massachusetts Department of Transportation (MassDOT) the Massachusetts Water
Resources Authority (MWRA), and the Department of Conservation and Recreation (DCR). The planning,
construction, operation and maintenance of these structures are integral to the flood hazard mitigation
efforts of towns. These agencies must be considered the town's regional partners in hazard mitigation.
These agencies also operate under the same constraints as communities do including budgetary and
staffing constraints and they must make decisions about numerous competing priorities. In the sections that
follow, the plan includes recommendations for activities where cooperation with these other agencies may
be necessary. Implementation of these recommendations will require that all parties work together to
develop solutions. Rail (MBTA).
REGIONAL AND INTERCOMMUNITY FACILITIES WITHIN WATERTOWN
Major facilities owned, operated and maintained by state or regional entities include:
• Watertown Dam (DCR)
• Cambridge Reservoir and Stony Brook Dams (Cambridge Water Department)
• Weston Dam, Norumbega Dam, and Schenck's Pond Dams (MWRA)
• State Route 20 (Main Street)
• MBTA Bus Lines
• MWRA water distribution mains and wastewater collectors
NEW DEVELOPMENT AND INFRASTRUCTURE
As part of the process of developing recommendations for new mitigation measures for this plan update,
the Town considered the issues related to new development, redevelopment, and infrastructure needs in
order limit future risks. Taking into consideration the Zoning and Stormwater Ordinances, priorities for the
future include bylaw updates for stormwater management, upgrading intraoperative communications,
installation of key generators, and coordination of dam management with state agencies.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC HAZARD MITIGATION STRATEGY 80 of 124
PROCESS FOR SETTING PRIORITIES FOR MITIGATION MEASURES
The last step in developing the Town's mitigation strategy is to assign a level of priority to each mitigation
measure so as to guide the focus of the Town's limited resources towards those actions with the greatest
potential benefit. At this stage in the process, the Local Hazard Mitigation Planning Team had limited
access to detailed analyses of the cost and benefits of any given mitigation measure, so prioritization is
based on the local team members' understanding of existing and potential hazard impacts and an
approximate sense of the costs associated with pursuing any given mitigation measure.
Priority setting was based on local knowledge of the hazard areas, including impacts of hazard events, the
extent of the area impacted, and the relation of a given mitigation measure to the Town's goals. In
addition, the local Hazard Mitigation Planning Team also took into consideration factors such as the
number of homes and businesses affected, whether or not road closures occurred and what impact closures
had on delivery of emergency services and the local economy, anticipated project costs, whether any
environmental constraints existed, and whether the Town would be able to justify the costs relative to the
anticipated benefits.
Table 35 below demonstrates the prioritization of the Town's recommended hazard mitigation measures.
For each mitigation measure, the geographic extent of the potential benefiting area is identified as is an
estimate of the overall benefit and cost of the measures. The benefits, costs, and overall priority were
evaluated in terms of:
Estimated Benefits
High Action will result in a significant reduction of hazard risk to people and/or
property from a hazard event
Medium Action will likely result in a moderate reduction of hazard risk to people
and/or property from a hazard event
Low Action will result in a low reduction of hazard risk to people and/or property
from a hazard event
Estimated Costs
High Estimated costs greater than $100,000
Medium Estimated costs between $10,000 to $100,000
Low Estimated costs less than $10,000 and/or staff time
Priority
High Action very likely to have political and public support and necessary
maintenance can occur following the project, and the costs seem reasonable
considering likely benefits from the measure
Medium Action may have political and public support and necessary maintenance has
potential to occur following the project
Low Not clear if action has political and public support and not certain that
necessary maintenance can occur following the project
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC HAZARD MITIGATION STRATEGY 81 of 124
HAZARD MITIGATION STRATEGY
Table 35: Prioritization of Mitigation Measures
Mitigation Action Geographic Estimated Estimated priority
Coverage Benefit Cost
DAMS
1. Maintain coordination with operators of
Watertown Dam and dams upstream of Charles River High Low High
Watertown in Waltham and Weston floodplains
FLOODING
2. Continue developing storm water program to
c Town-wide High Medium High
comply with the MS4 permit
3. Maintain updated Flood Information Rate Maps
maps information and town ordinance. Town-wide High Low High
4. Upgrade pumps and improve site drainage. Cunniff
Elementary Medium Medium Medium
School
5. Upgrade pumps and improve site drainage. Watertown Medium Medium Medium
High School
6. Test Program to fund and assist homeowners with
Rutland Street Medium Medium Medium
pumps.
7. Study feasibility of creating stormwater utility
Town-wide Medium Medium Medium
WIND
8. Increase contract labor for tree maintenance Town-wide Medium Medium Medium
program
MULTI-HAZARD
9. Upgrade communications to a uniform single
system that will serve Police, Fire, and Public Works,
including interconnections conduit. The Town is having
a study done by Cyber-Comm, and awaiting a Town-wide High High High
decision by the FCC regarding radio frequency
availability.
10. Upgrade all fixed generators as needed. The
Fire Dept, Police and DPW all have generators. The
town hall recently added one. The schools are being
rebuilt with generators added through the capital Town-wide High High High
budget process.
GEOLOGIC HAZARDS
11. Identify public buildings that may be vulnerable
to earthquakes and investigate options to make them Town-wide Low Low Low
more resistant to earthquakes
IK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
N1 PC HAZARD MITIGATION STRATEGY 82 of 124
Mitigation Action Geographic Estimated Estimated priority
Coverage Benefit Cost
BRUSH FIRE HAZARDS
12. Evaluate the status of fire access roads and
maintain or upgrade if needed Town-wide Low Low Low
13. Provide public information about brushfire
hazards and preventive measures for property Town-wide Low Low Low
owners.
WINTER STORMS
14. Identify public buildings that may be vulnerable
to damage from snow loads and conduct a structural Town-wide Low Low Low
assessment if needed
DROUGHT HAZARDS
15. Adopt guidelines for new development to
promote drought tolerant landscaping and site Town-wide Medium Low Medium
design measures
EXTREME TEMPERATURES
16. Conduct a public awareness program on the risks
of extreme temperatures and resources available to Town-wide Medium Low Medium
residents
17. Adopt Site Design regulations to increase shade
tree plantings near buildings, increase trees used in
parking areas and along public ways. Town-wide h Low Medium
RECOMMENDED MITIGATION MEASURES
INTRODUCTION TO RECOMMENDED MITIGATION MEASURES TABLE 36
Description of the Mitiaation Measure — The description of each mitigation measure is brief and cost
information is given only if cost data were already available from the community. The cost data represent
a point in time and would need to be adjusted for inflation and for any changes or refinements in the
design of a particular mitigation measure.
Priority — As described above and summarized in Table 35, the designation of high, medium, or low
priority was done considering potential benefits, areas affected, and estimated project costs.
Implementation Responsibility — The designation of implementation responsibility was done based on a
general knowledge of what each municipal department is responsible for. It is likely that most mitigation
measures will require that several departments work together and assigning staff is the sole responsibility
of the governing body of each community.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
1APC HAZARD MITIGATION STRATEGY 83 of 124
Time Frame — The time frame was based on a combination of the priority for that measure, the complexity
of the measure and whether or not the measure is conceptual, in design, or already designed and awaiting
funding. Because the time frame for this plan is five years, the timing for all mitigation measures has been
kept within this framework. The identification of a likely time frame is not meant to constrain a community
from taking advantage of funding opportunities as they arise.
hh
Potential Fundina Sources — This column attempts to identify the most likely sources of funding for a specific
measure. The information on potential funding sources in this table is preliminary and varies depending on
a number of factors. These factors include whether or not a mitigation measure has been studied,
evaluated or designed, or if it is still in the conceptual stages. MEMA and DCR assisted MAPC in reviewing
the potential eligibility for hazard mitigation funding. Each grant program and agency has specific
eligibility requirements that would need to be taken into consideration. In most instances, the measure will
require a number of different funding sources. Identification of a potential funding source in this table does
not guarantee that a project will be eligible for, or selected for funding. Upon adoption of this plan, the
local team responsible for its implementation should begin to explore the funding sources in more detail.
Additional information on fundina sources — The best way to determine eligibility for a particular funding
source is to review the project with a staff person at the funding agency. The following websites provide
an overview of programs and funding sources.
Army Coros of Enaineers (ACOE) — The website for the North Atlantic district office is
http://www.nae.usace.army.mil/. The ACOE provides assistance in a number of types of projects
including shoreline/streambank protection, flood damage reduction, flood plain management
services and planning services.
Massachusetts Emeraency Manaaement Aaency (MEMA) — The grants page
httDs://www.mass.aov/hazard-mitigation-assistance-grant-programs describes the various Hazard
Mitigation Assistance Program.h
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC HAZARD MITIGATION STRATEGY 84 of 124
Table 36: Recommended Hazard Mitigation Measures
Hazard Category/ Mitigation Measure Priority Implementation Time Estimated Potential Funding
Location Responsibility Frame Cost Sources
Dams
1. Charles River Dams Maintain coordination with High Dept. of Public 2019- Staff Time Watertown
operators of Watertown Works, with DCR, 2023 General Fund
Dam and dams upstream of MWRA, and City of
Watertown in Waltham and Cambridge
Weston
Flooding
2. Town-wide Continue developing storm High Dept. of Public 2019- Staff time and Enterprise Fund and
Drainage water program to comply Works 2023 Consultants Sewer Fund
Infrastructure with the MS4 permit 1 00,000/year
3. FIRM mapping and Maintain updated town High Planning Dept. 2019- Staff time Watertown
bylaws Flood Information Rate 2023 General Fund
Maps (FIRM) maps
information and town
ordinance.
4. Cunniff Elementary Upgrade pumps and Medium School Dept./Public 2019- TBD School Building Fund
School improve site drainage. Works Dept. 2023 / FEMA
5. Watertown High Upgrade pumps and Medium School Dept./Public 2019- TBD School Building Fund
School improve site drainage. Works Dept. 2023 / FEMA
6. Rutland Street Test Program to fund and Medium Dept. of Public 2019- $70,000 Watertown
assist homeowners with Works 2023 General Fund
pumps. Mitigation Fund
IK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IVIAPC HAZARD MITIGATION STRATEGY 85 of 124
Hazard Category Mitigation Measure Priority Implementation Time Estimated Potential Funding
Location Responsibility Frame Cost Sources
7. Town-wide Evaluate the feasibility of Medium Dept. of Public 2020- $50-100,000 Watertown
Drainage creating stormwater utility Works / Stormwater 2023 and Staff Time General Fund;
Infrastructure Advisory Committee Sewer Fund
Wind Hazards
8. Town-wide wind Increase contract labor for Medium Dept. of Public 2019- $50,000 Watertown
hazards tree maintenance program. Works Tree 2023 General Fund
Warden
Multi-Hazards
9. Town-wide Multi- Upgrade communications to High Fire Dept. 2019- $2.2 million Watertown
hazard: integrated a uniform single system that Police Dept. 2023 General Fund
communications will serve Police, Fire, and Dept. of Public FEMA
Public Works, including Works
interconnections conduit. The
Town is having a study done
by Cyber-Comm, and
awaiting a decision by the
FCC regarding radio
frequency availability.
10. Town-wide Upgrade all fixed High Fire Dept. 2019- $150,000 Watertown
Municipal Facilities: generators as needed. The Police Dept. 2023 General Fund
Multi-hazard--power Fire Dept, Police and DPW Dept. of Public FEMA
outage all have generators. The Works
town hall recently added
one. The schools are being
rebuilt with generators
added through the capital
budget process.
VK CITY OF WATERTOWN- DRAFT HAZARD MITIGATION PLAN- 2019 UPDATE
IVIAPC HAZARD MITIGATION STRATEGY 86 of 124
Hazard Category Mitigation Measure Priority Implementation Time Estimated Potential Funding
Location Responsibility Frame Cost Sources
Geologic Hazards
11. Town-wide: Public Identify public buildings that Low Planning Dept. 2020- Staff time Watertown
Buildings-Earthquake may be vulnerable to Emergency 2023 General Fund
hazards earthquakes and investigate Management
options to make them more
resistant to earthquakes
Wildfire Hazards
12. Town-wide: Evaluate the status of fire Low Fire Department 2020- Staff time Watertown
Brush Fire hazards access roads and maintain 2023 General Fund
or upgrade if needed
13. Town-wide: Provide public information Low Fire Department 2020- Staff time Watertown
Brush Fire hazards about brushfire hazards and 2023 General Fund
preventive measures for
property owners.
Winter Hazards
14. Town-wide Public Identify public buildings that Low Dept. of Public Works/ 2020- Staff time Watertown
Buildings: Snow loads may be vulnerable to Planning Dept. 2023 General Fund
damage from snow loads
and conduct a structural
assessment if needed
Drought Hazards
15. Town-wide: Adopt guidelines for new Medium Community 2020- Staff time Watertown
drought development to promote Development and 2023 General Fund
drought tolerant Planning Dept.
landscaping and site design Conservation
measures Commission, Planning
Board, ZBA
VK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IVIAPC HAZARD MITIGATION STRATEGY 87 of 124
Hazard Category Mitigation Measure Priority Implementation Time Estimated Potential Funding
Location Responsibility Frame Cost Sources
Extreme Temperatures
16. Town-wide: Conduct a public awareness Medium Health 2020- Staff time; cost Watertown
Extreme heat and cold program on the risks of Department/.. 2023 for developing General Fund
extreme temperatures and Emergency & distributing
resources available to Management. education
residents materials
17. Town-wide: Adopt Site Design Medium Community 2020- Staff Time Watertown
Extreme heat and cold regulations to increase Development and 2023 General Fund
shade tree plantings near Planning Dept.
buildings, increase trees Planning Board, ZBA
used in parking areas and
along public ways.
h
IK CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
IVIAPC HAZARD MITIGATION STRATEGY 88 of 1 24
SECTION 9 : PLAN ADOPTION &
MAINTENANCE
PLAN ADOPTION
The Watertown Hazard Mitigation Plan 2019 Update was adopted by the Board of Selectmen on [ADD
DATE]. See Appendix D for documentation. The plan was approved by FEMA on [ADD DATE] for a five-
year period that will expire on [ADD DATE].
PLAN MAINTENANCE
Although many of the mitigation measures from the Towns previous Hazard Mitigation Plan have been
implemented, since that plan was adopted there has not been an ongoing local process to guide
implementation of the plan. Such a process is needed over the next five years for the implementation of
this plan update, and will be structured as described below.
MAPC worked with the Watertown Hazard Mitigation Planning Team to prepare this plan. After approval
of the plan by FEMA, this group will meet to function as the Hazard Mitigation Implementation Team, with
the Fire Chief designated as the coordinator. Additional members could be added to the local
implementation team from businesses, non-profits and institutions. The Town will encourage public
participation during the next 5-year planning cycle. As updates and a review of the plan are conducted
by the Hazard Mitigation Implementation Team, these will be placed on the Town's web site, and any
meetings of the Hazard Mitigation Implementation Team will be publicly noticed in accordance with town
and state open meeting laws.
IMPLEMENTATION AND EVALUATION SCHEDULE
Mid-Term Survey on Progress — The coordinator of the Hazard Mitigation Implementation Team will
prepare and distribute a survey in year three of the plan. The survey will be distributed to all of the local
implementation group members and other interested local stakeholders. The survey will poll the members
on any changes or revisions to the plan that may be needed, progress and accomplishments for
implementation, and any new hazards or problem areas that have been identified.
This information will be used to prepare a report or addendum to the local hazard mitigation plan in order
to evaluate its effectiveness in meeting the plan's goals and identify areas that need to be updated in the
next plan. The Hazard Mitigation Implementation Team, coordinated by the Town Engineer, will have
primary responsibility for tracking progress, evaluating, and updating the plan.
Beain to Prepare for the next Plan Update — FEMA's approval of this plan is valid for five years, by which
time an updated plan must be approved by FEMA in order to maintain the town's approved plan status
and its eligibility for FEMA mitigation grants. Given the lead time needed to secure funding and conduct
the planning process, the Hazard Mitigation Implementation Team will begin to prepare for an update of
the plan in year three. This will help the Town avoid a lapse in its approved plan status and grant
eligibility when the current plan expires.
The Hazard Mitigation Implementation Team will use the information from the Mid-Term progress review to
identify the needs and priorities for the plan update and seek funding for the plan update process.
Potential sources of funding may include FEMA Pre-Disaster Mitigation grants and the Hazard Mitigation
it CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC PLAN ADOPTION AND MAINTENANE 89 of 124
Grant Program. Both grant programs can pay for 75% of a planning project, with a 25% local cost share
required.
Prepare and Adopt an Updated Local Hazard Mitiaation Plan — Once the resources have been secured to
update the plan, the Hazard Mitigation Implementation Team may decide to undertake the update
themselves, contract with the Metropolitan Area Planning Council to update the plan or to hire another
consultant. However the Hazard Mitigation Implementation Team decides to update the plan, the group
will need to review the current FEMA hazard mitigation plan guidelines for any changes. The Watertown
Hazard Mitigation Plan Update will be forwarded to MEMA and DCR for review and to FEMA for
approval.
INTEGRATION OF THE PLANS WITH OTHER PLANNING INITIATIVES
Upon approval of the Watertown Hazard Mitigation Plan 2019 Update by FEMA, the Local Hazard
Mitigation Team will provide all interested parties and implementing departments with a copy of the plan
and will initiate a discussion regarding how the plan can be integrated into that department's ongoing
work. At a minimum, the plan will be reviewed and discussed with the following departments:
• Fire Department/Emergency Management
• Police Department
• Public Works Department
• Community Development and Planning
• Conservation Commission
• Parks and Recreation
• Board of Health
• Building
Other groups that will be coordinated with include large institutions, Water District, Chamber of
Commerce, land conservation organizations and watershed groups. The plans will also be posted on a
community's website with the caveat that a local team coordinator will review the plan for sensitive
information that would be inappropriate for public posting. The posting of the plan on a web site will
include a mechanism for citizen feedback such as an e-mail address to send comments.
The Hazard Mitigation Plan will be integrated into other town plans and policies as they are updated and
renewed, including the Open Space and Recreation Plan, Comprehensive Emergency Management Plan,
and Capital Investment Program.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC PLAN ADOPTION AND MAINTENANE 90 of 124
". SECTION 10: LIST CAF REFERENCq
City of Cambridge, Emergency Action Plan, Cambridge Reservoir Dam and Stony Brook Dam, 2013
Environment America Research and Policy Center, When It Rains It Pours—Global Warming and the Increase
in Extreme Precipitation, July 2012
FEMA, Flood Insurance Rate Maps for Middlesex County, MA, 2010
FEMA, HAZUS, httos://www.fema.aov/hazus
FEMA, Local Mitigation Plan Review Guide; October 1, 201 1
FEMA, Flood Insurance Rate Maps for Middlesex County, MA, 2013
MA Department of Conservation and Recreation, Emergency Action Plan, Watertown Dam, 20 7 8
MA Department of Conservation and Recreation, Office of Water Resources
MA Emergency Management Agency, State Hazard Mitigation Plan, 2013
MA Geographic Information System, McConnell Land Use Statistics, 2005
MA Office of Dam Safety, Inventory of Massachusetts Dams
MA Water Resources Authority, Emergency Action Plan, Norumbega and Schenck's Pond Dams, 2078
MA Water Resources Authority, Emergency Action Plan, Weston Reservoir Dam
Metropolitan Area Planning Council, Geographic Information Systems Lab
New England Seismic Network, Weston Observatory, httr)://aki.bc.edu/index.htm
Northeast States Emergency Consortium, website httr)://www.nesec.ora/
NOAA, National Centers for Environmental Information, website
Town of Watertown, Open Space and Recreation Plan 2015
Town of Watertown, Stormwater Ordinance
Town of Watertown,
Town of Watertown, Wetlands Ordinance
Town of Watertown, Zoning Ordinance
Union of Concerned Scientists, Confronting Climate Change in the U.S. Northeast, 2007
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
}APG APPENDICES 91 of 109
U.S. Army Corps of Engineers, Ice Engineering Group, Ice Jam Database
U. S. Census, 2010, and American Community Survey, 2017
USGS, National Water Information Center, website
St CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAIPC APPENDICES 92 of 109
APPENDIX
PP , A: MEETING
AGENDAS
Watertown Hazard Mitigation Plan
LOCAL HAZARD MITIGATION TEAM
Meeting #1
Tuesday, March 6, 10:30 AM
Watertown Fire Department, 99 Main Street
AGENDA
1. Review Project Scope of Work and Schedule
2. Update Critical Facilities Inventory and Mapping
3. Identify/update local hazards:
a) Flood Hazard Areas
b) Fire Hazard Areas (brushfires/wildfires)
c) Dams
d) Other hazards
4. Identify/Update New and Potential Development Sites
5. Discuss Public Involvement and Outreach
• Identify local stakeholders
• Schedule first public meeting
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAP APPENDICES 93 of 109
Watertown Hazard Mitigation Plan
LOCAL HAZARD MITIGATION TEAM
Meeting #2
Friday, August 10, 10:00 AM
Watertown Fire Department, 99 Main Street
AGENDA
1. Review and Update Hazard Mitigation Goals
2. Update Existing Mitigation Measures
a. Identify any updates/changes to existing mitigation
b. Status of mitigation / any needed changes
3. Review status of Recommended Mitigation Measures from the
2012 Plan:
e) Mitigation that was completed
f) Mitigation partially completed
g) Mitigation not completed
h) Identify mitigation measures to retain in 2018 Plan Update
4. Prepare for First Public Meeting (September)
• Schedule first public meeting
• Identify list of local stakeholders & contact into
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
N1AP APPENDICES 94 of 109
Watertown Hazard Mitigation Plan
LOCAL HAZARD MITIGATION TEAM
Meeting #3
Tuesday, December 18, 10:00 AM
Watertown Public Works Department
AGENDA
1. Finalize Recommended Mitigation Measures for the 2019 Plan:
2. Prepare for Second Public Meeting
• Scheduled for January 8, 2019 with the Town Council
• Identify list of local stakeholders & contact into
VCCITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
APPENDICES 95 of 109
[This page intentionally left blank]
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
N1AP APPENDICES 96 of 109
"PENDIX B : HAZARD MAPPING
The MAPC GIS (Geographic Information Systems) Lab produced a series of maps for each community.
Some of the data came from the Northeast States Emergency Consortium (NESEC). More information on
NESEC can be found at http://www.nesec.org/. Due to the various sources for the data and varying levels
of accuracy, the identification of an area as being in one of the hazard categories must be considered as
a general classification that should always be supplemented with more local knowledge.
The map series consists of eight maps as described below. The maps in this appendix are necessarily
reduced scale versions for general reference. Full sized higher resolution PDF's of the maps can be
downloaded from the MAPC File Transfer Protocol (FTP) website at:
ftD://ftD.maDc.ora/Hazard Mitiaation Plans/maps/Watertown/
Map 1. Population Density
Map 2. Potential Development
Map 3. Flood Zones
Map 4. Earthquakes and Landslides
Map 5. Hurricanes and Tornadoes
Map 6. Average Snowfall
Map 7. Composite Natural Hazards
Map 8. Hazard Areas
Mapl: Population Density — This map uses the US Census block data for 2010 and shows population
density as the number of people per acre in seven categories with 60 or more people per acre
representing the highest density areas.
Map 2: Development — This map shows potential future developments, and critical infrastructure sites.
MAPC consulted with town staff to determine areas that were likely to be developed or redeveloped in
the future. The map also depicts current land use.
Map 3: Flood Zones — The map of flood zones used the FEMA NFIP Flood Zones as depicted on the FIRMs
(Federal Insurance Rate Maps) for Middlesex County (2010) as its source. This map is not intended for use
in determining whether or not a specific property is located within a FEMA NFIP flood zone. The currently
adopted FIRMS for Watertown are kept by the Town. For more information, refer to the FEMA Map
Service Center website http://www.msc.fema.gov. The definitions of the flood zones are described in
detail on this site as well. The flood zone map for each community also shows critical infrastructure and
repetitive loss areas.
Map 4: Earthquakes and Landslides — This information came from NESEC. For most communities, there was
no data for earthquakes because only the epicenters of an earthquake are mapped. The landslide
information shows areas with either a low susceptibility or a moderate susceptibility to landslides based on
Sf, CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC APPENDICES 97 of 109
mapping of geological formations. This mapping is highly general in nature. For more information on how
landslide susceptibility was mapped, refer to http://pubs.usgs.gov/pp/pl 1 83/ppl 183.html.
Map 5: Hurricanes and Tornadoes — This map shows a number of different items. The map includes
the storm tracks for both hurricanes and tropical storms, if any occurred in this community. This information
must be viewed in context. A storm track only shows where the eye of the storm passed through. In most
cases, the effects of the wind and rain from these storms were felt in other communities even if the track
was not within that community. This map also shows the location of tornadoes with a classification as to the
level of damages. What appears on the map varies by community since not all communities experience the
same wind-related events. These maps also show the 100 year wind speed.
Map 6: Average Snowfall - This map shows the average snowfall. It also shows storm tracks for
nor'easters, if any storms tracked through the community.
Map 7: Composite Natural Hazards - This map shows four categories of composite natural hazards for
areas of existing development. The hazards included in this map are 100 year wind speeds of 110 mph or
higher, low and moderate landslide risk, FEMA Q3 flood zones (100 year and 500 year) and hurricane
surge inundation areas. Areas with only one hazard were considered to be low hazard areas. Moderate
areas have two of the hazards present. High hazard areas have three hazards present and severe hazard
areas have four hazards present.
Map 8: Hazard Areas — For each community, locally identified hazard areas are overlaid on an aerial
photograph dated April, 2008. The critical infrastructure sites are also shown. The source of the aerial
photograph is Mass GIS.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
PC APPENDICES 98 of 109
ftw�
LLj,
kL,,-
IL
a Cs
'411
I twt
4L
L hi ar
ULL Ac. ul
04
LAtm 06
'C'b"
MAPC
FEMA Hazard
Wigatiorl Ranning Grant
r WATERTO N, MA
Map 2_Lana use
I'
t
iala•F
_ rAn ra'Iwadnwrxe9�• �{�ylrr
s l�rw..I.ro S71YL IrILMtl
T / ��ap71eA
I 1�44*A�7?I �Irwerrw
YF'-•
=ui x'ryr
M.ai,in Graff �.I.�o.b
RSycwilyl
i 1i Nn*u lyµy3wlyl —%eel
Wlqv&k~
ot.wwm VL k 80nea
-mrtnwrt.l
IM16JHIIH
+ 41 LSr�do(>r7Yrlr�3
p o ono '3'S k111 CJ
r64�
� �wnr.�la'we T mw•
�4YYa WrLi..K
E—W i7ll l ILL-1•717rT1
llfwwLL
IK
-.ra��a� R1�1.•rl
u0rwu ro[ilrr��rrrM�
awiv�fr+Tr4Ri.n rs i'.LY�i
t`-- Ywlp�iW
J/
CITY OF WATERTOWN — DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC APPENDICES 100 of 109
+ MApc
1
I ' _
EEMA Hazard
Mihpucn Planning Grant
,li I WATERTOWN, MA
Mail 3; F7ov0 Zones
• .�. __��r ame. .m.a le.nurrd
x �•��-.-; wrw���w�r rr w�.•rn�u.e.�..�
Can�opnmAlece•
• 1
i
- miw
aF+�- M'� feed 3arwa,�G17
omue Ai Po70d4
��1 ��I�iraYl•
Lt&H gh m
mrw Rd 1.
i ae,ae
j _•e Mi+h.-r
A �
c�rw-v esK
y • 9 13.25 0.9 Mips
d%
r .I
AM `
JOE
q
IN If
IK
�5� � { •} - f —t ,� tl �� �a -� r. �L�z�Y.name.
CITY OF WATERTOWN — DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MA PC APPENDICES 101 of 109
MAPC
FEMA Hat2ltl
MrIgRL6u l PIannlrg G'drlL
}' WATERTOWN, MA
' flap 4 Earthquakes f Landallde"5
wry
En"
Dr WON I u r+ + r, �r wa Ir+rwrrvw�r.Sxs` mllr eono
a ChNIBRIZ)GE
All IZoees
WALTHIN
Tm I'd
� � �� � - r Ti.ii 91G4w. —bYi Roulf
ti I S QhllfhfA
1 ' YUf'Y+OYHi.•id-06 l[rir+ILf lydh 15%
of:L..Ir 14 imgl rt.I.r{4eiQL4�I
.p.L.KM+nr�IG r Ma c w
f i { -rh P.+i7L{9P�Ir 04M7Faf�Me
J L ___ d.—d.—}m Ih—L�%
f I CO IM;V":4V bW 1^4MPP^Q
O 4 1!1 0.t Mlles
'41 -
L �
" DOWN
cj Wh I.
W9l LI w nflM,
_ .�i•�Imkti..ur I.I.•m!I I I
" - - bwai.rt.YYryti.+wF1..i+w
rA{i[4.4Yh Y14
:wA LLS'SSLF
IK CITY OF WATERTOWN — DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC APPENDICES 102 of 109
.t MA
"* FEMA Hazard
Mi-tigetian Planning Grant
WATERTOWN, MA
GELVDW Map 5: Hurftanesll-amadwq
WALrHAki
ih Lm
CWHROGE .DuS.11m.r...el,.. r- BJRorvar
■Itr�51w.Lw 9r wn'ccae
Tomndoeo-. -9rtru Sow`
aapkMl DMINM uYd mC
wowwl P171T i0b YW Wild 9W*2
,Ib ___Csngrrf YrWhlEYi Yiy}F�I�,r
•.••QdEp3r17 HUMLPM wWP4
wa w-. T.�w�- IIIIIIIIII� 1fl4 rw q.
W,�cari Sum 1LP M1Yh'
mwuary+ram
T 1.113 ww-I
�I ref
Tgly
6 4 7v P.'S Mllgg
. L 4r�ruW ari
n w..lr.�r.�w mtl�lmra«ma
r.rr Rr,y
_ In ILL'JOii
CITY OF WATERTOWN — DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAP APPENDICES 103 of 109
• 1 o '
}-�
m
F!w ztM.
�.
IL
-Pppq
} � t
�� „
IK (Do
MAPC
PE m Hivaro
' 1 ATERTOWN r MA
Map 7:00rnp0ti+tp Na'.riral HA4ar19
CenlpLrl�r rrrrlLymrde 614s
x3 5•F: :L'[:,b Jfr?Ihw+M r QT"Iw+"M-IJR Rft
}r IWIxrI,xM+`I •rkonMe LeLL 5rn
.. ww. N1 Reldr
�ulrFFso� —ui.Hq+w:
a�1P'a'""1� —•see 17ru1.
'br Fm+Y
I,nw—w�
IBMwu—d717r— T irinsWaw
l ,
# x,.aaw x.r.r iR Fdl u—
I lmra
yF A� (US 0.5Imi4m
}
'1
�4_
114
7 44kylr L+Yy1 FMMIr W""..+¢"
riarw.tmxr�r.ww
r\.-w Lk ig m6v-k*
01—P—d—Mi MJI NI:.4Wl?ra
1L's unlcr Ir 4+a ha.s Yaa 4vF�9 tr.uu..rscr
- m dao.bll.]ILL411n�...
Il.w..ux�nztia�rrx,...r.,x.•y...
w.►an.awrmmoww xwr^++ruwors.;
Swn+Lra w
CITY OF WATERTOWN — DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
I;IA APPENDICES 105 of 109
MAP
f 19
r — FEMA Hazard
M ftmlor+Pianning GraM
# ATE RTOWN. MA
f
FIELM.INT Map$: I.Q a3 Hazard Areas
1 hUn lxM
s+44 r *+Y^Sala•r
PVABF;iGI;C +one.&*"fL k..�I,a• _Ccnwulgr
x �pom"t=ihu Rw Lam
— bm
Uak gsa+.w .Y ikd
Kimw Am
n1 Db.r.h A— riFyon.
r7 �rb--q 15-c-br
K
IK
�• k!eer
C�41p�Maf
' k711gx
} T .
ti
-- V mil i.�h.1.3nY
..Ta1•��r�+.r.lFY14
F..IJ 7YALL
CITY OF WATERTOWN — DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
MAPC APPENDICES 106 of 109
APPENDIX C: PUBLIC MEETINGS
Amanda Linehan, Communications Manager, Metropolitan Area Planning Council
617-933-0705, alinehana-maac.ora
CALENDAR LISTING / MEDIA ADVISORY
WATERTOWN'S HAZARD MITIGATION PLAN TO BE DISCUSSED AT
DECEMBER 4 PUBLIC MEETING
Who: Watertown residents, business owners, representatives of non-profit organizations and
institutions, and others who are interested in preventing and reducing damage from natural
hazards.
What: At a meeting of the Joint Public Works and Public Safety Committees on Tuesday,
December 4 at 7:00 PM, a presentation will be made by the Metropolitan Area Planning
Council (MAPC), which is assisting the Town with the preparation of its Hazard Mitigation
Plan.
The Town of Watertown is preparing a Hazard Mitigation plan that will document natural
hazards that affect the Town, such as floods, hurricanes, winter storms, and earthquakes, as
well as actions that the Town can take to reduce its vulnerability to these hazards.
When: Tuesday, December 4, 2018, 7:00 PM
Where: Joint Meeting of the Public Works and Public Safety Committees
Richard E. Mastrangelo Council Chamber
Watertown Administration Building
149 Main Street, Watertown, MA
MAPC is the regional planning agency for 101 communities in the metropolitan Boston area,
promoting smart growth and regional collaboration. More information about MAPC is
available at www.maac.ora.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC APPENDICES 107 of 109
Hazard Mitigation Plan
Pubhc Meefing
Natural hazards can - serious impactsthe Town
,{rM1• wJ,'.y �i{• . .A,"L h
The Town of Watertown is preparing a Hazard Mitigation Plan to help
the town reduce its vulnerabTfity to natural hazard events such as
flooding, hurricanes, and winter starms- Please join the Town for a public
presentation about the Hazard Mitigation Plan at a joint meeting of the
Public Works and Public Safety Committees:
Date: • . + D ecernber
IM IM •
WatertownLocation: Richard E. Mastrangelo Council Chamber
• ■ • Building
149 Main Street, Watertown, MA
For more information, please contact
Martin Pillsbury at mai1Jsbury manc_ara PC
Y 41 I-L I: Y.•--H•J Li4X .•
CITY OF WATERTOWN-DRAFT HAZARD MITIGATION PLAN-2019 UPDATE
APPENDICES 108 of 109
Amanda Linehan, Communications Manager, Metropolitan Area Planning Council
617-933-0705, alinehan(cbmapc.ora_
CALENDAR LISTING / MEDIA ADVISORY
WATERTOWN'S HAZARD MITIGATION PLAN TO BE PRESENTED AT
JANUARY 8 PUBLIC MEETING
Who: Watertown residents, business owners, representatives of non-profit organizations and
institutions, and others who are interested in preventing and reducing damage from natural
hazards.
What: At a meeting of the Watertown Town Council on Tuesday, January 8, 2019 at 7:00 PM, a
presentation will be made by the Metropolitan Area Planning Council (MAPC), which is
assisting the Town with the preparation of its updated Hazard Mitigation Plan.
The Town of Watertown has prepared an updated Hazard Mitigation plan that documents
natural hazards that affect the Town, such as floods, hurricanes, winter storms, and
earthquakes, as well as actions that the Town can take to reduce its vulnerability to these
hazards.
When: Tuesday, January 8, 2018, 7:00 PM
Where: Meeting of the Town Council
Richard E. Mastrangelo Council Chamber
Watertown Administration Building
149 Main Street, Watertown, MA
MAPC is the regional planning agency for 101 communities in the metropolitan Boston area,
promoting smart growth and regional collaboration. More information about MAPC is
available at www.mapc.ora.
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC APPENDICES 109 of 109
Hazard Mitigation Plan
Pubhc Meefing
Na tural - # _ the Town
of Wa - . - - d . esses
V,
_ .ram•_.
The Town of Watertown is preparing a Haza-rd WtTgatTon Plan to help
the town reduc-e its vulnerability to natural hazard events such as
flooding, hurricanes, and wTnter storms- Please join the Town for a public
presentation of the Draft Hazard Mitigation Plan at a meeting of the
Town Council- questions and comments from the public are welcome at
the meeting or afterwards until Jonuary 18, 2019_
- Tuesday,
Time: 7:00 t
Richard E. Mastrange lo C ouncfl C hamb-
Watertown A dmirkistration Building
, ■ M ai n Stre et,Water tovym, MA
For mare TnformatTon, please contact 1K
Martin PiIIshury at m r)i I Isb ury Oftmer)c-ora
MAPC
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
APPENDICES 110 of 109
Watertown Public Meeting Notification
Dear Town of Watertown stakeholder:
The Watertown Hazard Mitigation Plan is being updated to help the town reduce its vulnerability to
natural hazard events such as flooding, hurricanes and winter storms. Natural hazards can have serious
impacts on the Town of Watertown and its residents and businesses. The Metropolitan Area Planning
Council (MAPC) is assisting the Town in the preparation of the updated plan.
Please join the Town for a presentation on the Draft Watertown Hazard Mitigation Plan Update at a
public meeting on the following date and location:
Tuesday, January 8 at 7:00 PM
Watertown Town Council Meeting
Richard E. Mastrangelo Council Chamber
Watertown Administration Building
149 Main Street, Watertown, MA
Please feel free to forward the attached flyer to residents, business owners and anyone who may
interested in preventing and reducing damage from natural hazards in Watertown.
Best regards,
Martin Pillsbury
Martin Pillsbury I Director of Environmental Planning
Metropolitan Area Planning Council
60 Temple Place Boston, MA 021 11
617.933.0747 mpillsburv(d)maac.ora. , www.maac.ora_
P FAR
a
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
M APC APPENDICES 111 of 109
Watertown Public Meeting Notification
City/Town Clerks
Belmont, Boston, Cambridge, Newton, and Waltham
Dear City Clerk,
The Town of Watertown is preparing its updated Hazard Mitigation Plan to reduce the town's
vulnerability to natural hazard events such as flooding, hurricanes, and winter storms. The plan will
identify a set of hazard mitigation measures, including structural improvements, regulatory changes,
and outreach efforts related to mitigating natural hazards in the town.
As part of the planning process, Watertown's neighboring communities are being notified of a public
meeting on the draft plan to be hosted by the Watertown Town Council:
Tuesday, January 8, 2019 at 7:00 PM
Richard E. Mastrangelo Council Chamber
Watertown Administration Building
149 Main Street, Watertown, MA
A flyer announcing the meeting is attached. Please post this as a public meeting. If you have any
questions about this please feel free to contact me.
Best regards,
Martin Pillsbury
Martin Pillsbury
Director of Environmental Planning
Metropolitan Area Planning Council
60 Temple Place
Boston, MA 021 1 1
617.933.0747
mr)illsbury(0)maac.ora
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
MAPC APPENDICES 112 of 109
APPENDIX D : PLAN ADOPTION
CERTIFICATE OF ADOPTION
TOWN COUNCIL
TOWN OF WATERTOWN, MASSACHUSETTS
A RESOLUTION ADOPTING THE
TOWN OF WATERTOWN HAZARD MITIGATION PLAN 20 7 9 UPDATE
WHEREAS, the Town of Watertown established a Committee to prepare the Town of Watertown
Hazard Mitigation Plan 2079 Update; and
WHEREAS, the Town of Watertown Hazard Mitigation Plan 2079 Update contains several potential
future projects to mitigate potential impacts from natural hazards in the Town of Watertown, and
WHEREAS, duly-noticed public meetings were held by the Joint Committees on Public Safety and Public
Health on December 4, 2018 and the Watertown Town Council on January 8, 2019
WHEREAS, the Town of Watertown authorizes responsible departments and/or agencies to execute their
responsibilities demonstrated in the plan, and
NOW, THEREFORE BE IT RESOLVED that the Town of Watertown TOWN COUNCIL adopts the Town of
Watertown Hazard Mitigation Plan 2079 Update, in accordance with M.G.L. 40 §4 or the charter
and ordinances of the Town of Watertown.
ADOPTED AND SIGNED this Date.
Name(s)
Title(s)
Signature(s)
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
M APC APPENDICES 113 of 109
[This page intentionally left blank]
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
N1AP APPENDICES 114 of 109
To be added after the plan is approved by FEMA
VcCITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN—2019 UPDATE
APPENDICES 115 of 109
CITY OF WATERTOWN—DRAFT HAZARD MITIGATION PLAN— 2019 UPDATE
N1AP APPENDICES 116 of 109