COMMUNITY-SUPPORTED WATER QUALITY MONITORING ON THE RIDEAU RIVER
Every year, we receive several questions from the public about the water quality in the Rideau River and whether it is safe for swimming and other recreational activities, particularly in terms of E. coli counts. Ottawa Public Health monitors water quality once a week at the City of Ottawa’s supervised beaches, which are Britannia Beach, Mooney’s Bay Beach, Petrie East Bay, Petrie River, and Westboro Beach. The results are available at the Ottawa Public Health website and updated on a weekly basis. Please visit the OPH website for important information on understanding your risks before swimming, how to protect your health during and after swimming, and staying safe around water. Swimming in rivers can be dangerous due to unpredictable currents, hidden underwater obstacles, and sudden changes in water depth. Always assess the river conditions, avoid swimming alone, be aware of your surroundings, and exercise extreme caution when entering or engaging in activities near or in the river. Drowning can occur quickly and silently in rivers, often without the dramatic signs people expect.
This year, in response to public requests, we have decided to test the water quality at several locations on the Rideau River to gain a better understanding of the water quality and E. coli concentrations along the river. We are doing this as a public service, and we do not receive funding for this testing. We strategically selected five sampling locations, starting with Manotick Mill upstream of Ottawa and then proceeding to Brewer Park, Windsor Park, Brantwood Park, and Springhurst Park. We will carry out E. coli testing in June, July and August, once a week on Wednesdays, with the occasional sample on days where there are reported combined sewer overflows (CSO’s).
We hope that our complementary water quality testing at these five additional sites will help fill some of the missing data and knowledge gaps in establishing the water quality and safety of the Rideau River, and will assist the public, municipal, and public health officials in making informed decisions.
Please note that we do not provide swim/no swim recommendations. We simply measure and provide the water quality results, which will subsequently be compiled and analyzed in a comprehensive scientific study. By using this information, you acknowledge and accept the inherent risks associated with river activities and agree to take full responsibility for your safety. Stay vigilant and prioritize safety to enjoy the Rideau River responsibly.
WATER QUALITY TEST RESULTS
We collect water samples at each location from different spots and immediately transport the samples to our laboratory in a cooler with an ice pack. Reported values below that exceed 200 E. coli per 100 mL of water do not meet the Ontario Water Quality Standards. E. coli counts lower than 200 E. coli per 100 mL of water indicate that the water is safe for recreational activities. Please note that our results reflect conditions at the time of sampling and may not represent current or future water quality. We do not guarantee the safety of the water for swimming or other recreational activities.
Sampling locations are listed in the direction of river flow from south to north into the Ottawa River. Sampling dates are provided below.
We would like to thank Richard Kibbee, a senior Research Associate at the Ormeci Lab, for leading the sample collection and analyses.
Additional notes:
1. This week, we expanded our monitoring efforts by adding three new sampling sites: Dutchy’s Hole, Strathcona Park, and Bordeleau Park. These locations allow us to track water quality continuously downstream, right up to where the Rideau River meets the Ottawa River. As a reminder, the primary goal of our project is to establish the water quality of the section of the Rideau River that flows through Ottawa. Our site selection is based on scientific coverage of the river, rather than on recreational use.
2. We are frequently asked why the water quality at Mooney’s Bay is worse than that at other locations. Mooney’s Bay is an artificial bay formed during the construction of the Rideau Canal. It has stagnant waters, and the water quality is affected by various factors, including the size of the crowds, birds and other wildlife, warmer temperatures, and rainfall events. Additionally, a pump that is used to circulate the water in the bay was not operational this year. In summary, test results from Mooney’s Bay are specific to that location and do not indicate the broader condition of the Rideau River.
3. You may notice that E. coli concentrations at Windsor Park are generally higher than at most other sites, though they remain below the Ontario limits. This increase is largely due to inputs from Sawmill Creek, which flows into the Rideau River just upstream of Windsor Park. The spike in E. coli levels diminishes quickly, and concentrations return to lower levels by the time the river reaches Brantwood Park.
NEW! Results from August 28, 2025 samples (samples were collected in pouring rain, which elevates the numbers)
Manotick Mill: 20 E. coli per 100 mL water
Brewer Park: 137 E. coli per 100 mL water
Windsor Park: 327 E. coli per 100 mL water
Brantwood Park: 42 E. coli per 100 mL water
Springhurst Park: 49 E. coli per 100 mL water
Results from August 19, 2025 samples
Manotick Mill: 15 E. coli per 100 mL water
Brewer Park: 60 E. coli per 100 mL water
Windsor Park: 139 E. coli per 100 mL water
Brantwood Park: 68 E. coli per 100 mL water
Springhurst Park: 40 E. coli per 100 mL water
Dutchy’s Hole: 77 E. coli per 100 mL water
Strathcona Park: 277 E. coli per 100 mL water (lots of shore birds were observed during sampling, and the water depth was less than 1 ft.)
Bordeleau Park: 110 E. coli per 100 mL water
Results from August 13, 2025 samples
Manotick Mill: 16 E. coli per 100 mL water
Brewer Park: 38 E. coli per 100 mL water
Windsor Park: 161 E. coli per 100 mL water
Brantwood Park: 45 E. coli per 100 mL water
Springhurst Park: 59 E. coli per 100 mL water
Additionally, Mooney’s Bay, as measured and reported by Ottawa Public Health, has 594 E. coli per 100 mL of water.
Results from August 6, 2025 samples
Manotick Mill: 27 E. coli per 100 mL water
Brewer Park: 16 E. coli per 100 mL water
Windsor Park: 170 E. coli per 100 mL water
Brantwood Park: 69 E. coli per 100 mL water
Springhurst Park: 46 E. coli per 100 mL water
Additionally, Mooney’s Bay, as measured and reported by Ottawa Public Health, has 173 E. coli per 100 mL of water.
Results from July 30, 2025 samples
Manotick Mill: 20 E. coli per 100 mL water
Brewer Park: 13 E. coli per 100 mL water
Windsor Park: 121 E. coli per 100 mL water
Brantwood Park: 81 E. coli per 100 mL water
Springhurst Park: 41 E. coli per 100 mL water
Additionally, Mooney’s Bay, as measured and reported by Ottawa Public Health, has 238 E. coli per 100 mL of water.
Results from July 23, 2025 samples
Manotick Mill: 35 E. coli per 100 mL water
Brewer Park: 13 E. coli per 100 mL water
Windsor Park: 143 E. coli per 100 mL water
Brantwood Park: 52 E. coli per 100 mL water
Springhurst Park: 42 E. coli per 100 mL water
Additionally, Mooney’s Bay, as measured and reported by Ottawa Public Health, has 255 E. coli per 100 mL of water.
Results from July 16, 2025 samples
Manotick Mill: 17 E. coli per 100 mL water
Brewer Park: 10 E. coli per 100 mL water
Windsor Park: 156 E. coli per 100 mL water
Brantwood Park: 55 E. coli per 100 mL water
Springhurst Park: 51 E. coli per 100 mL water
Additionally, Mooney’s Bay, as measured and reported by Ottawa Public Health, has 65 E. coli per 100 mL of water.
Results from July 9, 2025 samples
Manotick Mill: 12 E. coli per 100 mL water
Brewer Park: 55 E. coli per 100 mL water
Windsor Park: 128 E. coli per 100 mL water
Brantwood Park: 75 E. coli per 100 mL water
Springhurst Park: 62 E. coli per 100 mL water
Additionally, Mooney’s Bay, as measured and reported by Ottawa Public Health, has 317 E. coli per 100 mL of water.
Results from July 2, 2025 samples
Manotick Mill: 17 E. coli per 100 mL water
Brewer Park: 19 E. coli per 100 mL water
Windsor Park: 99 E. coli per 100 mL water
Brantwood Park: 80 E. coli per 100 mL water
Springhurst Park: 36 E. coli per 100 mL water
Additionally, Mooney’s Bay, as measured and reported by Ottawa Public Health, has 42 E. coli per 100 mL of water.
Results from June 26, 2025 samples
Manotick Mill: 6 E. coli per 100 mL water
Brewer Park: 27 E. coli per 100 mL water
Windsor Park: 53 E. coli per 100 mL water
Brantwood Park: 80 E. coli per 100 mL water
Springhurst Park: 79 E. coli per 100 mL water
Additionally, Mooney’s Bay, as measured and reported by Ottawa Public Health, has 16 E. coli per 100 mL of water.
WATER SAMPLING LOCATIONS
Yellow circles show our sampling locations for the water quality testing.
