WSSC Water reports that about 63 percent of its roughly 1,800 yearly main breaks and leaks happen from November to February, and about 42 percent of its mains are over 50 years old. A break in the street is the utility's problem. A frozen or split pipe inside your house is yours, so know where your shut-off is.
Key takeaways
- About 63 percent of WSSC Water's roughly 1,800 yearly main breaks and leaks happen between November and February, according to its own figures.
- From November 26 to December 15, 2025, WSSC logged 293 breaks and leaks as the Potomac fell from about 49 to 32 degrees Fahrenheit.
- A main break in the street belongs to the utility, while a frozen or split pipe inside the house belongs to the owner, and the water it releases is the owner's to deal with.
- Most freeze losses can be prevented with insulation, heat, open cabinet doors, disconnected hoses and a known shut-off.
- Pipes often burst on the thaw, not at the freeze, so a morning with low pressure is a reason to walk the house before the day warms.
How common are winter breaks in the WSSC system?
Very. WSSC Water, which serves Montgomery and Prince George's counties, reports roughly 1,800 main breaks and leaks a year, with about 63 percent between November and February, and about 42 percent of its mains over 50 years old. In one stretch, November 26 to December 15, 2025, it logged 293 breaks and leaks as the Potomac fell from about 49 to 32 degrees.
The reason is physical. Cold water makes pipes brittle and ground movement stresses old joints, and the colder the river, the colder the water in the system. A sharp drop in temperature produces a cluster of failures within days.
The utility has also issued advisories when the system was under strain. In January 2025 it asked customers for one day of essential water use only. These are events at the system level, but they matter at home because pressure can drop and service can be interrupted.
Is the break mine or the utility's?
Water in the street, low pressure on your whole block, or a discolored supply point to a main break, and the utility fixes it. Water inside your house, or between the meter and the house, is yours. If you are unsure, call the utility, because it can check the main and tell you where its responsibility ends.
Utilities generally own the main under the street and the line to the meter. Beyond the meter, the pipe belongs to the property owner. Where exactly that line falls can differ by utility, so ask yours.
Anne Arundel and Howard county towns around Bowie are outside WSSC's Montgomery and Prince George's area, so check your bill for the utility that serves you.
Photograph any water in the street and the time you noticed it, which can help when the utility asks for details or when you talk to your insurer about damage that followed.
| Where the water is | Usually who deals with it | First step |
|---|---|---|
| Flowing in the street or from the main | The water utility | Report it to the utility; keep out of the water |
| Low pressure on the whole street | The water utility | Call the utility to ask about an outage or break |
| Between the meter and the house | Usually the owner; confirm with the utility | Shut off at the meter or curb if you can, and call a plumber |
| Inside the house | The owner | Close the main inside, then call a plumber and a restoration crew |
| Frozen but not split | The owner | Thaw slowly and check for leaks |
What should I do when service returns after a main break?
Open a cold tap at the lowest point and let it run until the water is clear, then check each fixture for leaks, look at the water heater and the ceilings below bathrooms, and watch the meter with everything off. Air and sediment can disturb old pipes when pressure returns, and a weak joint may only show itself then.
When a main is shut off for repair, the house lines drain or hold air. When service returns, pressure surges and sediment in the system can show up as cloudy or rusty water. Running a cold tap until it clears is the usual practice, and aerators on taps may need cleaning.
Use the return of service as a leak check. A meter that keeps moving with every fixture off, a hiss in a wall, or a new damp patch are reasons to close the main and call. If you left taps open during the outage, check that none was left open over a sink with the stopper in.
What do I do when a pipe bursts inside the house?
Close the main shut-off, open a low tap to drain the lines, switch off the water heater, keep away from wet outlets and call a plumber and a restoration crew. Photograph the damage while you wait and lift valuables off wet floors. Phones are answered 24/7 and a crew is dispatched as fast as one is available.
Find the main before the cold arrives. In a house with a basement it is usually where the line enters through the foundation wall, near the meter. If you cannot turn it, say so on the call and you will be talked through the next step.
Water that runs for a short time into a wall is much cheaper to dry than water that runs overnight. Details of the cleanup are in burst pipe water damage and frozen pipe water damage.
The thaw is also when you should look for damage you did not know about. Check ceilings under bathrooms and exterior-wall kitchens, cabinet bases against outside walls and the corners of the basement, before the day warms up and the pipes start to run.
- Close the main shut-off and drain the lines
- Switch off the water heater
- Stay out of rooms with water at outlets
- Photograph the water and the damage
- Call a plumber for the pipe and a crew for the water
- Keep a record of what you did and when
How do pipes freeze, and why do they burst on the thaw?
Ice forms in a pipe, blocks the flow and builds pressure between the ice and a closed tap. The pipe cracks at its weakest point, but the ice plug holds the water in. When the temperature rises and the ice melts, the full pressure of the supply pushes water out, which is why leaks often start hours after the coldest night.
Pipes against exterior walls, in garages, in crawl spaces and in unheated corners of basements are the usual victims. Hose bibs that were not disconnected are another classic. A pipe in the middle of a heated house seldom freezes.
Winters around Bowie are cold enough for this to be a regular risk. January lows average roughly 21 to 24 degrees Fahrenheit, and about 15 inches of snow falls in a typical year. These are rounded figures from secondary climate sources.
How do I keep pipes from freezing?
Keep the heat on at about 55 degrees Fahrenheit or higher if you are away, open cabinet doors on exterior walls, let a tap drip during a hard freeze, disconnect and drain outdoor hoses, insulate exposed pipes and seal drafts near them. Know where your main is, and ask someone to check an empty house during a cold week.
Small steps do most of the work. A foam sleeve on a garage supply line costs little and holds the cold off for hours. A cabinet door left open lets house heat reach the pipe at the back of the sink.
If your house has a section that has frozen before, treat it as a known weak point. A plumber can reroute or insulate it before the next cold snap.
Unheated additions deserve special attention. A sunroom, an enclosed porch or a bump-out over a garage often has supply lines or a radiator pipe that was never meant to see freezing weather, and the cold finds them first.
| Where | What to do | When |
|---|---|---|
| Outdoor hose bibs | Disconnect hoses, drain and cover | Before the first hard freeze |
| Garage and unheated basement lines | Insulate with foam sleeves; seal drafts | Autumn |
| Kitchen and bath cabinets on outside walls | Open doors on very cold nights | During a freeze |
| Crawl space and vents | Close vents; check insulation | Before winter |
| Empty house or vacation | Keep heat on; ask someone to check; or shut off and drain | Any cold week |
| Main shut-off | Find it, label it and test it | Autumn |
What does a freeze loss look like in older houses?
Older houses tend to have more exposed runs: porch and addition lines, garages, crawl spaces and plumbing in exterior walls with thin insulation. Belair-era houses are about sixty years old, Hyattsville's historic houses date from the 1870s to the 1930s, and Mount Rainier has early-twentieth-century homes. These are general patterns, not a count, and each house differs.
In attached homes in Mount Rainier and Brentwood, a split pipe can send water through a shared wall to a neighbor. Tell the neighbor right away and expect each household to need its own assessment.
In Greenbelt, the concrete-block homes dry slowly, so a freeze leak in a masonry wall needs patience. Crews working there talk about drying days before demolition.
What about my insurance?
Many policies treat a sudden freeze-and-burst differently from a long-term leak or flood, but the wording varies, so the insurer decides under your policy. Report the loss promptly, keep photographs, the moisture record and receipts, and do not assume a result. A contractor cannot promise coverage, and neither can this site.
Policies often expect you to take reasonable steps to protect the property, such as heating the house or draining the pipes when you leave. Check your policy for conditions that apply to vacancy.
If water entered from outside, for example through a flooded basement after snowmelt, that is a different cause. Maryland Insurance Administration guidance says standard homeowners policies generally exclude flood, and backup needs an endorsement.
Frequently asked questions
What should I do if my water goes out during a cold snap?
Call the utility to ask whether there is a break, and keep taps closed if the water is off to avoid flooding when service returns. Check the house for frozen sections, and be ready to close the main if you find a split.
Can I thaw a pipe myself?
A slow thaw with warm air from a hair dryer or a space heater placed safely is acceptable. Never use an open flame, and if the pipe is already split, leave it alone and close the main.
Is dripping a tap really helpful?
In a hard freeze, a slow drip from a tap on an exterior wall keeps water moving and relieves pressure. It helps most when combined with insulation and open cabinet doors.
How long does cleanup take?
Often three to five days of drying for a room, longer for cold, thick or masonry walls. Cold air carries little moisture, so heat may be needed. Readings decide when equipment leaves.
Who repairs the pipe?
A plumber, and in Montgomery and Prince George's counties plumbers are expected to be registered with WSSC Water. The restoration crew handles extraction, drying and cleanup.
Sources
This guide is general information for Prince George's County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.