Cambridge, Massachusetts Water Outage Today
Live Cambridge water outage reports, Cambridge Water Department’s emergency line and the system’s federal record.
Weather data by Open-Meteo.com
No water outage reports in Cambridge, Massachusetts in the last 24 hours
The most recent water outage report from Cambridge came in 10 days ago.
Who supplies water in Cambridge?
Drinking water in Cambridge, Massachusetts is supplied by Cambridge Water Department, which handles outages, main breaks and boil water notices for the city.
Public water systems in Massachusetts are regulated by the Massachusetts Department of Environmental Protection (MassDEP).
To report no water or a main break, call Cambridge Water Department at 617-349-4770.
Cambridge tap water system, by the numbers
Federal records name Cambridge Water Department as the public water system for Cambridge, with about 118,214 people on its mains.
| Item | Detail |
|---|---|
| Water system in EPA records | Cambridge Water Department (MA3049000) |
| Run by | Local government |
| People served | 118,214 through 15,001 service connections |
| Source of the water | Surface water (rivers, lakes or reservoirs) |
| Active facilities listed by EPA | 4 surface intakes, 1 treatment point, 2 storage tanks and reservoirs, 4 pump facilities |
| Connections to other systems | 1 |
| State regulator | Massachusetts Department of Environmental Protection (MassDEP) |
| Health-based violations since 2015 | 0 |
| Highest lead result (90th percentile) | 8 ppb, action level 15 ppb |
Source: EPA SDWIS (Safe Drinking Water Information System).
What feeds the taps in Cambridge
Cambridge drinks surface water. Cambridge Water Department draws it from Hobbs Brook Res. Low, Fresh Pond Res., and Stony Brook Res. and treats it before it goes into the distribution system. Treatment points named in EPA's facility list include Water Treatment Plant. After treatment the water is held in 2 storage tanks and reservoirs and pushed uphill by 4 pump facilities; that storage is the buffer that keeps taps running for a few hours after a pump or main fails.
What this means in an outage. Surface water needs a treatment plant running around the clock, so a plant shutdown, a raw-water pump failure or a long power cut at the plant can lower pressure across the whole service area, not just on one street. Boil water notices are more likely to be citywide after that kind of failure than after a single main break.
What causes water outages and low pressure in Cambridge
Water outages are local, so the likely cause depends on weather, pipe age and the grid. For Cambridge, these stand out.
- Freezing weather. Cambridge sees about 122 days a year with a low at or below 32°F, and 38 days at or below 20°F. The coldest morning in the 2015 through 2025 record came on February 24, 2015. The longest stretch with highs that never rose above freezing ran 27 days, ending February 21, 2015. Frost pushes into shallow service lines first. Mains follow when the ground heaves and thaws, which is why break counts climb a day or two after the temperature swings.
- Flooding and heavy rain. NOAA logged 139 flood, flash flood and heavy rain reports in Middlesex County from 2015 through 2026, and 10 days a year bring an inch of rain or more. Floodwater can undercut pipe crossings, swamp pump stations and overload treatment plants, and a notice to boil water often follows when it enters the system.
- Older neighborhoods and pipe. 58.6% of occupied homes in Cambridge were built before 1970, against 35.5% nationally. Streets of that age tend to sit on cast iron and early steel mains that are near or past their design life, which is where most breaks start.
- Storm-driven power loss. Thunderstorm wind, hail and tornado reports in Middlesex County number 378 since 2015. Pump stations and treatment plants that depend on Eversource run on the electric grid, so a storm that downs power lines can lower water pressure even when no pipe is damaged.
- Digging and utility work. Street projects, fiber installation and excavation near buried pipe regularly cut mains in Cambridge with no warning, usually on a day with perfectly ordinary weather.
- Planned shutoffs and a problem at one address. Valve replacements and new connections are announced ahead, often with door hangers. If neighbors have water, check your own shutoff valve, meter and pressure regulator before calling.
Freeze, heat and rain: the Cambridge weather record
Main break season in Cambridge runs from late fall into early spring, with the coldest stretch around December through February.
| Measure | Value |
|---|---|
| Days a year at or below 32°F | 121.6 |
| Days a year at or below 20°F | 38.5 |
| Days a year with a high at or below 32°F | 28.5 |
| Days a year at or above 95°F | 1.1 |
| Days a year at or above 100°F | 0 |
| Days a year with an inch of rain or more | 9.5 |
| Average annual precipitation | 47.8 in |
| Wettest year | 2018 (60 in) |
| Driest year | 2016 (36.4 in) |
| Coldest day in the record | February 24, 2015 |
| Hottest day in the record | August 4, 2022 |
Source: NASA POWER daily reanalysis (MERRA-2) for the city center, 2015–2025.
Freezing days peak in January, averaging 28 a year. Source: NASA POWER reanalysis, 2015–2025.
The wettest year was 2018 with 60 inches; the driest was 2016 with 36.4. Source: NASA POWER reanalysis, 2015–2025.
These counts come from a gridded reanalysis, which smooths out single-day extremes and can differ by a few degrees from an airport thermometer. Use them to compare seasons and years, not as official station records.
Is Cambridge water safe? Boil notices and EPA record
EPA lists no health-based violations for Cambridge Water Department since 2015. It also lists 39 monitoring or reporting entries that are about paperwork rather than water quality, such as a missed sample or a late report.
Most recent entries, all monitoring or reporting:
- April 2019: A missed or late monitoring or reporting requirement (chemical and radiological contaminants)
- April 2019: A missed or late monitoring or reporting requirement (chemical and radiological contaminants)
| Type of violation | Health-based | Monitoring and other |
|---|---|---|
| Chemical and radiological contaminants | 0 | 30 |
| Other | 0 | 8 |
| Public notice and annual reports | 0 | 1 |
Source: EPA SDWIS.
Monitoring and other Health-based
Violations are counted by the year the compliance period began. Source: EPA SDWIS.
A boil water notice in Cambridge is a separate thing from a violation. Cambridge Water Department issues one when pressure falls low enough for contamination to enter the pipes, after a main break is repaired, or when a routine test comes back positive. The Massachusetts Department of Environmental Protection (MassDEP) oversees the process, and the notice stays until clean samples come back, usually a day or two after pressure returns.
Lead service lines and old plumbing in Cambridge
The most recent 90th-percentile lead result filed for Cambridge Water Department is 8 ppb (2023). The federal action level is 15 ppb, so that result is under it, but not by much.
Highest result on file: 8 ppb. Source: EPA SDWIS.
The age of the housing matters more than the utility's test average: 58.6% of occupied homes in Cambridge predate 1970 and 1986 was the year lead pipe and solder were banned. Flush the cold tap after an outage and ask Cambridge Water Department whether your service line is on its lead inventory.
How long a water outage lasts in Cambridge
A crew that arrives at an ordinary main break in Cambridge usually needs 4 to 8 hours to isolate the pipe, dig, repair, flush and restore pressure. Large transmission mains, deep pipes and breaks under busy streets can take a day or more.
| Situation | Typical time |
|---|---|
| Planned shutoff | A few hours inside a window announced in advance |
| Ordinary main break | Roughly 4 to 8 working hours |
| Large or deep main | A day or two, sometimes three |
| Low pressure after a pump or power failure | Until power returns and tanks recover, often within a day |
| Boil water notice after service returns | Until two clean rounds of samples, usually 1 to 2 days |
| Frozen service line or meter | Depends on thaw; a plumber is usually needed |
Source: Utility practice, EPA and state boil water guidance.
Cambridge Water Department will post an estimated restoration time for a break that affects many customers; ask for the repair crew's estimate when you call.
How much water to keep on hand in Cambridge
Census figures put the typical Cambridge household at about 2.4 people. At one gallon per person per day that is 7 gallons for three days or 34 gallons for a two-week supply.
- 36.5% of homes are in buildings with 20 or more units. Upper floors lose pressure first, and rooftop tanks and booster pumps depend on building power.
- 66.5% of households rent. Tell your landlord or property manager about a leak or outage right away, since the shutoff valve may be theirs.
- Do not forget the water heater: the tank holds roughly 30 to 50 gallons you can drink after it is switched off and allowed to cool.
- If a planned shutoff or storm is coming, fill the tub and some buckets for flushing toilets and washing; keep drinking water in clean sealed containers.
Cambridge versus neighboring water utilities
| City | System | People served | Source | Health violations since 2015 | Highest lead (ppb) |
|---|---|---|---|---|---|
| Cambridge, MA | Cambridge Water Department | 118,214 | Surface | 0 | 8 |
| Boston, MA | Boston Water and Sewer Commission | 675,647 | Bought (surface) | 1 | 99.5 |
| Lowell, MA | Lowell Regional Water Utility | 120,418 | Surface | 1 | 2 |
| Nashua, NH | Pennichuck Water Works | 88,853 | Surface | 0 | 2 |
| Worcester, MA | Worcester Dpwp, Water Supply Division | 206,518 | Surface | 0 | 3 |
Source: EPA SDWIS.
Water outage pages for nearby cities
Cambridge boil water notices and main breaks
Cambridge Water Department posts Cambridge boil water notices, main breaks and planned shutoffs on its own site and alerts. What a notice requires: water outage guide.
Cambridge water outage questions
Who do I call about no water in Cambridge?
Cambridge Water Department at 617-349-4770, day or night. Use 911 only if a main break is flooding property or roads.
What is the source of Cambridge tap water?
Surface water supplies Cambridge, according to EPA records for Cambridge Water Department. It draws from Hobbs Brook Res. Low, Fresh Pond Res., and Stony Brook Res.
Is Cambridge tap water safe to drink?
EPA lists no health-based violations for Cambridge Water Department since 2015, and its latest 90th-percentile lead result is 8 ppb against the 15 ppb action level. Follow any boil water notice until the utility says it is over.
When is water main break season in Cambridge?
Winter, mostly. Cambridge sees roughly 122 days a year at or below freezing, and the peak runs December through February. Expect breaks to cluster just after sharp temperature swings.
Why is my water pressure low in Cambridge?
Check whether neighbors have the same problem. If they do, it is probably a main break, a pump problem or evening demand, and Cambridge Water Department should hear about it. If not, the cause is likely inside your own plumbing.
When will a boil water notice be lifted in Cambridge?
Typically a day or two. Bacteria tests take about 24 hours, so Cambridge Water Department cannot end a notice until clean samples come back; the Massachusetts Department of Environmental Protection (MassDEP) sets the rules for that process.
How much drinking water should I keep at home in Cambridge?
One gallon per person per day is the FEMA minimum. For Cambridge that means about 7 gallons to cover three days for an average household of 2.4, and 34 gallons for two weeks.
Are there lead service lines in Cambridge?
It depends on the age of your home. About 58.6% of occupied homes in Cambridge were built before 1970, and lead service lines remained legal until 1986. Contact Cambridge Water Department about your address and flush the cold tap after any outage.
Is there a water outage map for Cambridge?
This page shows resident reports from Cambridge for the last 24 hours. For a street-by-street picture, use the alerts and outage page of Cambridge Water Department; many utilities also text boil notices.
Recent water reports in Cambridge
- Water reports in Cambridge, last 24h
- 0
- Most recent water report here
- 10 days ago
- Water reports across Massachusetts, last 24h
- 0
- City population
- 118,403
Other outage types in Cambridge
Water Service Outages in cities near Cambridge
- Boston, MA 3 mi · Boston Water and Sewer Commission
- Lowell, MA 21 mi · Lowell Regional Water Utility
- Nashua, NH 33 mi · Pennichuck Water Works
- Worcester, MA 36 mi · Worcester Department of Public Works & Parks – Water
- Derry, NH 37 mi · Town of Derry Water
- Pawtucket, RI 37 mi · Pawtucket Water Supply Board
Report counts are user-submitted; other figures name their official source. How our data works
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