Sewer overflow information system
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This system indicates the current condition of our entire sewer network with regard to overflows into the Red and Assiniboine Rivers. It is based on a reading of high water sensors in the sewer pipes at various overflow locations along the city's rivers, like the one pictured above, together with an assessment of other indicators, such as river levels.
What do the coloured dots represent?
- A white dot indicates that there is a low probability of overflows.
- A grey dot indicates an increased likelihood of overflows.
- A black dot indicates a high probability of sewer overflows.
Where do sewer overflows occur?
Most overflows occur in the combined sewer system of our entire sewer network.
What are combined sewers?
Combined sewers are pipes that carry both wastewater (sewage from homes and businesses) and land drainage. There are about 1,280 kilometres of combined sewers. Typically, they serve areas of the city built before the 1960s.
When do combined sewers overflow?
Combined sewers carry all of the wastewater flow to the wastewater treatment plants during dry weather conditions. In fact, they can carry up to a minimum of 2.75 times the normal dry weather flow. However, during rainstorms they cannot handle all of the runoff that enters the sewer system. Most of the rain/wastewater mixture flows to the treatment plants, but some of the diluted wastewater overflows to the river system.
How often do sewer overflows occur?
Our annual average is 18 overflows during the recreation season (May 1 to September 30).
Are combined sewers unique to Winnipeg?
No. Many North American cities, including several others in Manitoba, have similar wastewater systems. Hundreds of communities built combined sewers because they were a cost-effective way to provide sewer service and improve drainage. Combined sewers in our city date from 1880. They were the first sewer infrastructure.
Do I have to take any special precautions if I use the rivers?
Yes. Dr. Michael Routledge, Medical Officer of Health with the Winnipeg Regional Health Authority, advises:
- Never drink river water, whether overflows are occurring or not.
- Do not swim in the river system at any time because of fast currents, cloudy water, and slippery, muddy banks.
- Wash your hands if they come in contact with river water, particularly before you touch food.
Fish caught in the rivers are safe to eat as long as they are cooked thoroughly.
Sometimes I see garbage floating in the rivers? Is this from a sewer overflow?
There are floating debris in the rivers when an overflow occurs. However, most of the time, the material has been washed into sewers from the streets during a rainstorm. Residents can help reduce floating debris by keeping their yards clean and not putting garbage down their household drain or toilets.
I see foam on the river. Is it harmful?
Foam on the river:
- is not harmful to the environment
- occurs naturally
- is usually seen on the Assiniboine River when the water level changes
- is sometimes brown in colour
- is caused by materials such as pollen and algae
- is similar to the foam you often see when waves crash on a beach
I see what looks like an oil slick on the river.
- could be caused by algae, oil or a combined sewer overflow
- contact us and report it
- we will investigate and determine if we need to take any action
I see what looks like green paint on the river or retention pond.
- likely caused by algae
- contact us and report it
- we will investigate and determine if we need to take any action
I see water draining from a pipe into a river/stream
- likely runoff from rainwater or snowmelt
- in winter, the drainage can cause unsafe conditions on the ice, so contact us and report it
What are you doing to reduce sewer overflows?
We could be investing up to $450 million over the next 25 years to reduce the number of combined sewer overflows from our current average of 18 to a target of 4 during the recreation season (May 1 to September 30). We will modify the system to allow us to store the sewage until it can be pumped to the treatment plants. We could also spend an additional $695 million on other wastewater system improvements 
(pdf - 364kb), such as reducing nutrients in effluent, and disinfecting effluent.
Our sewer service interruptions page also lists untreated wastewater discharges from the wastewater collection system.
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Summary of sewer overflows in the last 24-hour period. |
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This page was last updated on February 9, 2012, at 05:18 PM |
