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Columbia Slough Watershed Council

Watershed Facts

Watershed Facts

Columbia Slough Watershed Facts:

• 32,700 acres
• Contains Smith and Bybee Wetlands, the largest urban wetland in the United States
• Lower slough is a refuge for endangered salmon
• 175 bird species
• 26 fish species
• 6 lakes, 3 ponds, 50 total miles of waterways
• 30 miles of flood control levees
• 170,000 residents
• 2 universities, one community college
• Wildlife corridors
• Portland International Airport and Troutdale Airport
• Portland Marine Terminals
• 4,200 businesses
• Columbia South Shore Well Field-part of the City of Portland and City of Gresham’s drinking water
• Critical transportation corridors-I-5, I-205, I-83, and Highway 30
• 250,000 railroad cars pass through
• Water quality listed under 303(d)
• Six golf courses
• 40 mile Loop Trail-trail system over 150 miles
• Canoe and kayak launches
• 60% impervious surfaces


Resource Description
Groundwater Protection Program Brochure
City of Portland; Portland Water Bureau Groundwater Protection Program Information
Find out what watershed you live in!
If you live in the Portland Metro area this website is a tool to helping you find out what watershed you live in. Watershed information is located on the "Environmental" tab.