Water Main Cleaning Program
We clean water mains every year. Crews work 7 days a week, from 8:00 a.m. to as late as 11:00 p.m.
Water Services crews work every day of the year except Christmas Day. As well as cleaning the water mains, they repair water main breaks, inspect and maintain fire hydrants and replace water meters.
Water mains are underground pipes that carry water from the pumping stations to your street.
Cleaning the mains helps preserve the quality of water as it passes from our drinking water treatment plant to your taps.
Beginning in 2014, we fast tracked the schedule of the Water Main Cleaning Program to clean all 2,614 kilometres in a three-year program, compared to the routine program of six years. This is one of the measures we are taking to reduce discoloured water.
We force water through the water mains at a high speed and discharge it through hydrants into sewers. The fast moving water scours and cleans the mains. We leave the hydrants open until the water runs clear.
There are about 2,645 kilometres of water mains in Winnipeg. We will be cleaning about 849 kilometres of water mains this year, or about 32% of the water mains in Winnipeg.
Before and During the Cleaning
To keep your children safe, keep them away from the work area at all times.
To find out the day we will clean the mains on your street, check our weekly cleaning schedule
If you live in a house
We will hand deliver an envelope to your mailbox within four days before we clean the water main on your street. The envelope will contain a letter and a brochure with more information on the program.
If you live in an apartment
We will let your property manager/landlord know, within four days in advance, when the work will begin and how long it will take. We will leave a package of information, including a fact sheet on the program to hand out to tenants, and notices to post in the building.
If you operate a business
We will contact you within four days in advance to let you know when the work will begin and how long it will take. We will leave a package of information, including a fact sheet on the program.
It takes about 30 minutes to 1 hour to flush the water main on each street.
Often, water main cleaning can be completed without any water being discoloured.
However, discoloured water can happen while we clean the water main on your street or a street nearby.
If you experience discoloured water, please do not use any more water. This will help prevent sediment and discoloured water from entering the pipes in your home.
If you experience discoloured water, please do the following:
- Wait a few minutes.
- Turn on the cold water tap and let the water run for a few minutes.
- Then, collect some water in a light-coloured cup or container. If water is clear, you can use your water.
- If it is not clear, wait 30 minutes, check the water again. If your water is still discoloured after two to three hours, call 311.
- Please do not use any hot water or filtered taps before you are sure your water is clear.
After the Cleaning
Immediately after cleaning, your water may be discoloured. Water is sometimes discoloured after water main cleaning, but this should not last long. Do not use discoloured water for any purposes that require clean water, such as preparing food and beverages, medical and dental procedures, or laundry. This recommendation is because discoloured water does not taste, smell or look pleasant, and it can stain clothes. Health officials do not believe that drinking discoloured water would pose a health risk.
- Turn on a cold water tap and let the water run for a few minutes. Do not choose a tap that has a water filter connected to it, or the sediment may clog your filter. Do not use a hot water tap because it could draw sediment into your hot water tank.
- Catch some water in a light-coloured cup or container to see if it is clear. You can use your water if it is clear.
- If the water isn't clear, turn off the tap, wait 30 minutes and try again. If your water is still discoloured after 2 to 3 hours, phone 311
Apartment property managers, landlords and business operators
Before you turn your water back on to the building, we recommend that you:
- Turn on a cold water tap near the water shut-off valve (e.g., a tap in the mop sink in the maintenance room) and let the water run for a few minutes.
- Catch some water in a light-coloured cup or container to see if it is clear.
- Restore water to the rest of the building if the water is clear.
Your water may also be cloudy or smell of chlorine.
Water is cloudy when air gets in it and makes tiny bubbles. These bubbles are harmless and will disappear if you let the water sit for a few minutes.
We add enough chlorine to the water to keep it safe. You can easily get rid of the chlorine taste and smell by filling a container with water and keeping it in the fridge for drinking – much of the chlorine will leave the water overnight.
Drinking discoloured water should not make you sick, however, it may not smell, taste, or look pleasant. Health officials believe that drinking small amounts of discoloured water should not pose a health threat if accidentally consumed.
Monitoring and Flushing Techniques
Yes, our laboratory staff will randomly collect samples and test water quality from hydrants, homes, and businesses during the cleaning program.
No. We are using a unidirectional flushing technique, which uses 40% less water than conventional flushing.
During unidirectional flushing, water system valves are operated to create one-way flow to the water main to be cleaned. A hydrant connected to the main is then opened to remove the built-up sediment. This type of flushing increases the speed of the water flow in the main to about two metres or six feet per second (it is normally less than .3 metres or 1 foot per second). This high speed produces a scouring action in the mains, removing sediment deposits. The flushing starts at a clean water source (e.g., the water pumping stations) and moves towards the outer limits of the city. This ensures that clean water is always used to flush the mains.
In conventional flushing, the water used to flush the main does not always begin at the clean water source (the water pumping station), and the speed of the water is much lower than during unidirectional flushing. As a result, more water is required to thoroughly clean the water mains.
Yes. In addition to removing more sediment and using less water than conventional flushing, unidirectional flushing tests and exercises the water system valves and hydrants.
In the area we are cleaning this year, we will drain the water into the street catch basins, which typically flow to the land drainage system, and into the river. We will be using an environmentally friendly product (ascorbic acid) to remove the chlorine from the water before it drains to the catch basins. We will also collect and test samples to determine the quality of the water we drain to the catch basins.
Many cities have some type of flushing program to clean their water mains (e.g., conventional flushing or unidirectional flushing). This is considered the best way to improve water quality and increase the reliability of the water distribution system.