Beach Water Quality

Are you thinking about swimming today?

Swimming in recreational water can be a refreshing and exciting experience, especially in areas where the water quality has historically been good, like Ottawa’s supervised beaches. However, unlike pools, open water has additional risks to consider, such as potential bacteria from wildlife or human activity, weather conditions, and hidden hazards like rocks or sudden drop offs. It's important to be aware of the potential risks involved to ensure a safe and enjoyable time.

Know the factors that increase your risk

Deciding to swim should be based on the real-time conditions of the beach you're visiting. There are easy and effective ways to lower your risks and protect your health when swimming at a public beach. Knowing the risks can help you make an informed decision for you and for your family.

Know your risks before swimming
  • Heavy rain: Swimming is riskier if it’s raining heavily or if there has been heavy rainfall (20mm or more) in the last 24 to 48 hours. Rain can wash contaminants like bird or dog poop into the water, making it less safe.
  • Severe weather: Lightning is very dangerous, but high winds and heavy rain can also be hazardous and can occur suddenly during a thunderstorm.
  • Beach conditions: Swimming is riskier if there are visible problems around the beach like many birds, dead fish, algae, or debris in the water.
  • Cloudy water: High winds and waves can make the water cloudy, hiding hazards and washing contaminants into the water. If you can't see your feet in waist-deep water, it's riskier to swim.
  • Cuts or open wounds: Bacteria in the water can lead to infection when swimming with open cuts or open wounds. 
How to protect your health during and after swimming
  • Risks: Swimming in natural waters like rivers can cause injury or illness from microorganisms, leading to ear, eye, stomach, or urinary infections.
  • Precautions to take when entering the water: 
    • Take children to the toilet before swimming to reduce the risk of children peeing or pooping in the water.
    • Keep your head above and out of the water. Avoid swallowing water or putting it in your mouth. 
  • Precautions to take after exiting the water: 
    • Wash hands with soap and treated water or use alcohol-based hand rub after swimming or playing in the sand, and before eating or preparing food.
    • Shower as soon as possible after swimming and dry your ears thoroughly with a towel.

Stay safe around water
  • Supervised areas: Swim in areas with lifeguards on duty from noon to 7 pm during the supervised swimming season.
  • Close supervision: Always keep your child within arm's reach when they are in or around water, including pools, bathtubs, and other water sources. Never leave them alone, even for a moment.
  • Lifejackets: Ensure your children and weaker swimmers wear a properly fitted lifejacket or personal flotation device in and around water.
  • Babies: Hold your baby if they cannot sit without support. Never leave babies unattended.
  • Stay sober: Do not use alcohol, cannabis, or drugs when swimming or supervising others in the water.
  • Swimming lessons: Swimming lessons are beneficial but do not fully protect your child from drowning.
  • Emergency preparedness: Know what to do in an emergency, including how to perform CPR and calling 9-1-1.

Update to flag system - Recreation, Cultural and Facility Services Department

The red over yellow flag system is internationally recognized to establish lifeguard supervised zones and indicate the defined swimming area. Beginning this summer, these flags will be used to indicate the designated swimming area during lifeguard supervision hours.

  • Red over yellow flags – Indicate the designated supervised swimming area.
  • Green flag – Lifeguards are supervising the designated swimming area.
  • Red flag – Lifeguards are not supervising the designated swimming area.

Ottawa Public Health will no longer be issuing “no-swim advisory” days, previously communicated with a red flag. Instead, beach goers will be encouraged to consider potential risks associated with swimming before, during, and after visiting the beach.

Printable resource

What is beach water monitoring?

During the summer months, Ottawa Public Health (OPH) monitors water quality at the City of Ottawa's supervised beaches in accordance with the Ontario Public Health Standards.

Starting in 2025, water samples will be collected weekly to test for the presence of E. coli bacteria, meeting the requirement of the standards and aligning with the approach taken by most public health units in Ontario, as well as the National Capital Commission. Elevated levels of E. coli can indicate the potential presence of other disease-causing organisms, which can result in skin, ear, throat or gastrointestinal illnesses.

How are beaches sampled?

Samples are analyzed for E. coli bacteria by the Provincial Public Health Laboratory. The water quality results are used to track long-term trends in water quality and are less useful for daily decision making. A minimum of five water samples per beach are collected weekly. The geometric mean is calculated, and if it exceeds 200 E. coli per 100mL of water, the sample does not meet the Ontario Water Quality Standard.

Algae growth is monitored visually during sampling, and OPH will investigate any potential blooms. Learn about blue-green algae and how it can affect both recreational water and drinking water.

OPH does not close beaches unless there is a significant adverse event such as the presence of a harmful algal bloom, chemical spill or immediate safety hazard.

Why did OPH change from daily to weekly testing?

OPH’s historical sampling has built up a great understanding of how our beaches react to local conditions including weather events, with our beaches meeting the water quality standard nearly 85 per cent of the time. Water sample results provide a snapshot of water quality at a specific point in time – the time at which the sample is collected, yet water quality can change rapidly depending on environmental factors like rain, wind and wildlife.

Ottawa’s supervised beaches are all located on rivers which means the water is constantly moving.  Water samples take 18 to 24 hours to process at the laboratory, resulting in limited accuracy for determining the level of real-time risk posed by the water to the users of the beaches. This means that you could only know the water quality for the previous day at the time of sampling and the data or sample would not reflect the current conditions

Beach-specific information

The water quality results will be posted here for each Ottawa beach when testing begins on June 4.

Visuals in the dashboard may present conflicting information. Certain visuals will update sooner than others due to data caching on the Microsoft Power BI server.

To enter the Power BI report from the dashboard webpage using a keyboard, press Tab once after the “full screen mode” link and press Ctrl + Enter. A small box will appear in the top left corner of the report. Press Tab three times to navigate through the options and you will then be inside the report. From here you can navigate the content of the report using Tab and the other keyboard shortcuts enumerated in the Keyboard Shortcuts document.

The City of Ottawa Open Data keeps Beach water sampling data from previous years.

Having trouble viewing the report? Try viewing the report in full screen mode. 

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