Where
Bunker Hill · Monument Square · Winthrop Square · City Square · Thompson Square · Hayes Square · Sullivan Square · The Neck · Navy Yard
ZIP 02129
Water & sewer
Charlestown gets MWRA water from the Quabbin and Wachusett reservoirs, delivered through BWSC pipes. Report a main break or a house with no water to BWSC at (617) 989-7900, any hour.
Official pagePermits & inspections
Swapping a water heater or boiler in Boston needs a City plumbing permit even when nothing else changes. Only a contractor with a valid Massachusetts trade license can apply to Inspectional Services.
Official pageRowhouses, three-deckers and Navy Yard conversions
Census estimates count 10,107 housing units in ZIP 02129, and 50.3% of them date from 1939 or earlier. Charlestown has the largest share of attached single-family homes, the rowhouse category, of any Boston neighborhood ZIP on this site, at 15.9%. Another 23.8% of units are in three- and four-unit buildings, and 30.2% are in buildings of 20 or more. Ownership is split almost exactly in half (50.5% owner-occupied), and 37.2% of households heat with electricity, compared with 55.7% on gas.
The City's Climate Ready study sums up the housing as mostly low-rise row houses and wood-framed two- or three-family buildings, often raised but typically with a basement or below-grade finished space, and often vulnerable to flooding through windows at grade. In an attached rowhouse, a leak behind a shared wall can show up next door before it shows up in your own rooms.
The large buildings are mostly newer uses of old places. The Navy Yard closed on July 1, 1974; Building 42 became apartments in 1981, the redevelopment had produced about 990 homes, mostly condos, by the mid-1990s, and the Ropewalk was turned into apartments in 2021. The Bunker Hill public housing development has 1,100 affordable units, with a redevelopment plan that adds about 1,700 more. In buildings like these, shared risers and mains are usually the association's or management's responsibility, so start there when a leak crosses unit lines.
Sullivan Square and the low edges of the peninsula
Landfill long ago erased the narrow Charlestown Neck, and the edges of the peninsula are where the harbor and rivers push back. Climate Ready Boston calls the Sullivan Square waterfront the most important flood entry point in Charlestown. In today's 1% annual-chance flood, water would cross at Schrafft's City Center (529 Main Street / 465 Medford Street) and Ryan Playground; the depth on the Schrafft's lot would be about 0.7 feet now, 2.0 feet by the 2030s and 4.4 feet by the 2070s. The report also lists the combined stormwater and sewer systems among the Charlestown assets that such a flood would hit.
The 2016 citywide numbers show how fast exposure grows. In the near term, 20 structures are exposed at monthly high tides and 140 in a 1% flood; by the 2070s, more than half of Charlestown's land and close to 700 structures are. The count of residents inside a 1% flood rises from 1,340 with 9 inches of sea level rise to 5,180 with 36 inches. With 21 inches, expected around the 2050s, Charlestown flooding could reach the Charles River and bypass the New Charles River Dam. The City's 2022 Phase II plan covers the Navy Yard, the Little Mystic Channel and Constitution Wharf.
For a rowhouse with a basement bath or laundry, the plumbing question is whether sewage can come back up when the system is overwhelmed. State code calls for a backwater valve when fixtures are lower than the top of the manhole cover on the sewer that serves the house, and the owner is the one who installs and maintains it. Our emergency plumber page covers what to do while water is still coming in.
Winter: meters, service pipes and drafty basements
January nights at Logan average a low of 23.1°F. BWSC puts frost protection on the owner: keeping the service pipe and water meter from freezing is the property owner's job, and if the service pipe does freeze, the owner has to thaw it or call a licensed plumber. A frozen meter is replaced by BWSC, and the account is charged a fee based on the meter's size.
BWSC says most frozen meters trace back to drafts from an open basement door or window, worth remembering in a rowhouse basement with windows at grade. Seal openings, keep cabinet doors open on cold nights, let a faucet trickle where pipes run through unheated space, and thaw a frozen pipe with a hair dryer, never an open flame. Our frozen pipes page picks up from there.
Old service pipes can hold lead as well as freeze. BWSC replaces a qualifying private-side lead service at no cost to the owner, mostly between April and October; the Lead Hotline is 617-989-7888, and our Boston lead pipes guide explains eligibility.
What Charlestown callers usually need
- Frozen & burst pipes Frozen service pipes and meters in rowhouse basements, where BWSC says drafts from an open door or window cause most frozen meters.
- Emergency plumber Water entering below-grade rooms through windows at grade, or rising through floor drains, when a storm tide reaches Sullivan Square and the low edges of the peninsula.
- Water heaters Permitted water heater and boiler replacements in pre-1940 rowhouses and two- and three-family houses; Boston requires a permit even for a straight swap.
- Leaks & pipe repair Leaks behind shared rowhouse walls and in Navy Yard condo conversions, where water from one unit can surface in the next.
Plumbing in Charlestown: questions
Who pays when the water meter freezes in my Charlestown house?
The owner. BWSC makes property owners responsible for protecting the service pipe and meter from freezing. It replaces a frozen meter and charges the account a fee based on meter size, and a frozen service pipe is the owner's to thaw or to have a licensed plumber thaw.
Which parts of Charlestown flood first?
The Sullivan Square waterfront, according to Climate Ready Boston, which calls it Charlestown's most important flood entry point. A 1% flood today would cross at Schrafft's City Center and Ryan Playground. The City's later coastal planning also covers the Navy Yard, the Little Mystic Channel and Constitution Wharf.
Do I need a permit to replace a water heater in Charlestown?
Yes. The City of Boston requires a plumbing permit to replace or install a water heater or boiler even when no other work is being done, and only a contractor holding a valid Massachusetts trade license can apply. The fee is $20 plus $5 per fixture.
Nearby
Sources
- Boston Water and Sewer Commission (24-hour emergency line)
- BWSC residential FAQs (frozen service pipes and meters)
- BWSC on frozen pipes
- BWSC guidance on backwater valves
- BWSC Lead Replacement Incentive Program
- BWSC 2026 water quality report for Boston (MWRA source water)
- City of Boston plumbing permit (Inspectional Services)
- City of Boston: install or replace a water heater or boiler
- Climate Ready East Boston and Charlestown final report (City of Boston)
- Climate Ready Boston report (City of Boston, 2016)
- Coastal Resilience Solutions for East Boston and Charlestown, Phase II (2022)
- NOAA 1991-2020 climate normals, Boston Logan
- City of Boston: Charlestown neighborhood
- Wikipedia: Charlestown, Boston
- Wikipedia: Charlestown Navy Yard
- U.S. Census Bureau ACS 2020-2024 housing estimates for ZIP 02129 (Census Reporter)