August 2023 Advisory: The Oregon Health Authority has issued advisories against swimming or direct water contact due to harmful algae blooms, which can form during periods of hot weather. While the Willamette River’s bacteria levels are good (see results below), algae blooms can be harmful to your and your pets’ health. Please follow the Oregon Health Authority advisories.
Weekly Summer Testing
Environmental Services samples for E. coli bacteria and water temperature at five popular Willamette River locations each week from late May to September. Samples are taken on Wednesdays, and results are posted by Friday—just in time for the weekend. Results are consistently safe. All samples taken during the 2022 summer testing period showed good water quality.
- Cathedral Park Boat Launch, River Mile 5.6
- Portland Boathouse Dock at Hawthorne Bridge, River Mile 12.9
- Riverplace Marina Boat Dock, River Mile 13.2. This location is next to Poet's Beach.
- Willamette Park Boat Launch, River Mile 15.7
- Sellwood Riverfront Park Dock, River Mile 16.4
Check-the-Rec Email Updates: Sign up for weekly water quality updates directly to your email inbox through our free GovDelivery subscription service. Updates will be sent on Fridays during the summer recreation months.
Monthly Testing
Each month, year-round, Environmental Services collects water samples at three locations to track long-term water quality trends.
- Railroad Bridge, River Mile 6.8
- Morrison Bridge, River Mile 12.7
- Waverly Country Club, River Mile 17.9
Staying Safe on the River
Keep in mind many factors affect your safety on the river. These include water temperature, currents, and debris in the river, as well as your skills and ability in the water. While cold water is healthy for fish, low temperatures can be uncomfortable and even unsafe for people. Know the water, know your abilities, and stay safe while enjoying the river.
Algae Blooms
While Environmental Services tests for bacteria (the leading indicator of whether a water body is safe for recreation), the Oregon Department of Environmental Quality has information about another water hazard, algae blooms, which may form in slow-moving portions of rivers and lakes during hot weather.
If you see water that looks green or has a coating, the advice is, "if in doubt, stay out." To check if there is a current advisory, visit the Oregon Healthy Authority's webpage.
Where to Swim
Portland Parks & Recreations offers suggestions on where to swim and how to stay safe when recreating in the Willamette River.
How Did the River Become Clean Enough to Swim and Play?
The federal Clean Water Act has led to vast improvements in water quality in rivers throughout the country. In Portland, those improvements include ratepayers’ investment in the $1.4 billion Big Pipe project—the largest public works project in Portland history. Since Environmental Services completed the project in 2011, almost all combined sewer overflows (CSOs) to the Willamette River have been eliminated. With that drop in sewage, comes a drop in E. coli bacteria, an indicator of fecal matter and the single biggest health concern for swimming and other direct-contact recreation, according to the state Department of Environmental Quality. Other E. coli sources include poop from wildlife and pets. (Thank you for picking up after your dog.)
Find out other ways you can help keep our rivers clean and healthy.