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Water main and water pipe breaks

Note: Only watermain breaks resulting in water service disruptions are displayed in the banner above. Under normal circumstances, watermain breaks are repaired and water is back on within 48 hours. Water main break information is updated every 15 minutes if the status changes.

Underground water pipes known as water mains can sometimes leak or break. When a pipe leaks or a break happens, water can escape.

Because the water mains are under constant pressure, the water escaping will flow until the break is discovered, that section of the pipe is closed, and then repaired.

Like water mains, our sanitary sewer pipes also sometimes break and require repair.

After your water is restored

When your water is restored to service after a main break, there are three steps we recommend you take to ensure the quality of water in your home.

  1. Run water from all of your taps for 20 minutes. This doesn't need to a full stream, just a small stream the size of a pencil. Don't forget the taps that may be in your basement or utility room.
  2. Wash any tap aerators or screens in your home in hot, soapy water, and then disinfect them for 10 minutes in a solution of one part bleach to nine parts water.
  3. Disinfect any water filters in your home to the manufacturer's recommendations.

If you have questions or concerns about the quality of your water, even after following these steps, please call 311.

Questions about water main breaks

My water was turned off - why?

We do our best to notify customers of service interruptions when they occur. Unfortunately, we cannot predict the time or place of water outages. If you were not notified of service interruptions, it may have been because:

  • The leak was large in nature and could potentially cause property damage and needed to be dealt with in a timely manner.
  • No one was home when we were notifying residents. Please check your front door as crews try to leave notification if no one was available to answer the door.
  • Because the leak was discovered in the late evening or early morning, we did not want to disturb you.

If your water is off and you haven’t received any information, please contact 311.

How can I get water while the main is being fixed?

A water wagon is a portable tank of drinking water that provides emergency supply to customers. It is placed in a central location to provide customers access to water during an extended period of water outage. If you need to use a water wagon, you will find instructions on how to use it directly above the spigot on the water wagon.

For repairs like water main replacements, we may provide temporary water lines to property owners. A temporary water line connection is usually attached to either a fire hydrant or a close neighbour who has water service. Learn more at Temporary Water Lines.

How can I prepare for when my water is turned off?

You can prepare for a water service interruption by storing water in the fridge for drinking. Store water in your bathtub, clean pails, sinks, jugs or any clean container that is appropriate to hold water.

Ensure all your equipment that relies on water is handled according to the manufacturer's specifications. For example, air conditioners may be required to be powered off. Other equipment may have bypass valves or shut off valves that should be turned on or off. If you are not sure what to do, contact the manufacturer or the place of purchase.

What if I see a water main break?

Contact 311 and a Water Services crew will be dispatched to evaluate the situation.

What causes water main breaks?

Main breaks happen year-round. There are many contributing factors including:

Pipe Age

Age can contribute to main breaks as pipes reach the end of their life cycle.

Pipe Material and Soil Conditions

The material that pipes are made from can contribute to main breaks if the material is in soil conditions that cause the material to corrode or crumble. Soil conditions can vary greatly within a 20 meter stretch of pipe.


Ground temperature and water temperature can contribute to water main breaks. Prolonged periods of below zero temperatures can cause the soil to freeze quite deep into the ground. Frost depths in Calgary can range from 6 – 10 feet every winter. This freezing can cause expansion and contraction that creates force on the water main.

Pressure Changes in the System

Changes in pressure can cause main breaks. This usually occurs at points where there is a pre-existing weakness in the pipe. Overall system demands (such as very hot, dry days with high water use) can also cause changes in pressure that lead to main breaks.

What Causes Water Main breaks? Water main repair steps

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How is a water main fixed?

What is involved in repairing a water main?

When a call or customer request is received, a crew is dispatched to determine the location, impact and severity of the break. First the water main is "controlled", by closing nearby valves that control the mains. Depending on the type of leak, this will either reduce the flow of water to the affected water main or shut it off completely.

Once the general repair location has been identified and the water main is shut off, special equipment is used to find the precise location of the leak. Then, construction crews are dispatched to the location to begin the repairs. Prior to any excavation, the crews must identify the location of all utilities to ensure the repair can be done without damaging other utilities or endangering staff or the public.

Excavation exposes the problematic water main and the repair is completed. The pipes are then flushed and water is tested to ensure water quality before water service is restored.

After that, the damaged road, lane, sidewalk or lawn must be repaired to the match the existing surface features. This may take some time depending on the construction season, weather and the availability of equipment and materials.

How long does it take to repair a water main?

It can be difficult to predict when water service will be restored during a main break repair. The length of repair time can vary depending on the location of the leak, condition of the soil, the condition of the pipe, seasonal activities, availability of repair materials and difficulty and location of the excavation. However, we make every effort to minimize the length of time customers are out of water.

No one has come to fix the water main yet - why?

At any time, there are a number of emergency water service repairs required throughout Calgary. Projects must be prioritized based on factors such as the risk of property damage, impact to critical facilities (like hospitals or schools) and the number of customers that are out of water. We understand that water outages are a significant inconvenience and we always endeavor to get customer's water back on as soon as possible.

How does fixing water pipes impact my home?

Can I flush my toilet without water service?

You can continue to use the washroom during water interruptions by pouring stored water into your toilet bowl to empty its contents.

Is my water safe to drink?

Before water service is restored we flush the lines and then sample and test to ensure the high quality of the water. To flush the pipe system within your own home we recommend that you run each cold water tap used for drinking for five minutes.

Also, wash tap aerators and screens in hot soapy water then disinfect them for ten minutes in a solution of one part bleach to nine parts water. Disinfect any water filters to the manufacturer's recommendations.

My lawn was damaged by the repair. Will The City fix my lawn?

The City of Calgary does offer property rehabilitation services, including fixes to grass, loam, curbs or sidewalks. Learn more at Water Service Construction Property Rehab.

The water service line on my property needs repair. Who is responsible?

If the section of the service line to your home requires repair and it is on your property (determined by the property line) you are responsible for the repair. Find more information about service lines and service valves.​​