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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Ave, Suite 613, Portland, OR 97204

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Water Quality

  • Swimming in the Willamette River is fine most of the time. During the summer, Environmental Services regularly tests for E. coli bacteria to make sure that it’s safe.

  • Green infrastructure filters pollutants and helps recharge groundwater. Portland has more than 1,500 green street planters.

  • None of Portland’s waterways meet all water quality goals. Pollutants like copper from car brake pads can harm salmon.

  • Trees along streams and rivers help cool the water and filter pollution.

Graphic: Portland has about 300 miles of rivers and streams in the city.Good water quality protects the health of people who boat, swim, and fish in Portland’s rivers, play along the beaches, or explore our many smaller urban streams.

It’s also critical for fish and wildlife that live in or migrate through Portland. Many species, including salmon, are sensitive to even small amounts of pollution or changes in water temperature.

Water quality in Portland’s rivers and streams has improved since the early 20th century, when raw sewage and other pollutants from industry and development drained directly into the Willamette River and Columbia Slough. In the 1940s, young fish died within a short time of coming into contact with Willamette River water in Portland (see video footage in the Oregon State University archives).

Completion of the Columbia Boulevard Wastewater Treatment Plant in 1952, the Combined Sewer Overflow Control program in 2011, pollution prevention programs and many other actions by the City and community have improved Portland’s water quality. In the summer months, BES conducts weekly water quality testing to ensure that the Willamette River is safe for swimming, boating, and playing. To see test results and more info, visit Check the Rec at

However, pollution from homes, businesses and streets continues to be a problem for all of Portland’s streams and rivers. Pollutants like oils, pesticides, fertilizers, and heavy metals come from within Portland and from upstream sources. The City is responsible for protecting and improving water quality under state and federal regulations.

The City’s water quality programs monitor our waterways for many pollutants. The Watershed Report Cards use data about some key water quality indicators, such as temperature and E. coli, to give a summary of water quality in each of Portland’s watershed.

Explore Portland's Watersheds

See some of the actions we’re taking to improve water quality

Portland Area Watershed Monitoring and Assessment Program (PAWMAP)

More information about the city’s stream monitoring program and data

Stormwater Management

More information about Portland’s stormwater permit and programs

What We Measure

Learn more about the water quality indicators used in watershed report cards