What is a Watershed?
A watershed is the region or area that drains into a particular body of water. All of us live in a watershed. Any time it rains, any time you water your lawn or wash your car, the water soaks into the ground or runs off into the streams and rivers of your watershed.


Where is the Columbia Slough?
The Columbia Slough is a shallow, slow flowing waterway that parallels the Columbia River for about 18 miles from Fairview Lake in East Multnomah County through North and Northeast Portland to Kelley Point Park where the Slough meets the Willamette River.


What is a Slough?
The slough is a waterbody that is distinguished by low flow or stagnant water. The Columbia Slough is a 18 mile long series of slow moving wetlands, lakes and channels in the southern floodplain of the Columbia River.


How Clean is the Slough?
The Columbia Slough has had a long history of contamination. The Watershed is both industrial and a highly residential which results in varied challenges in restoring the health of the waterway. Despite its long history of environmental degradation the Columbia Slough is cleaner today than it has been in the last 100 years.


What are the sources of pollution?
- Failing septic systems
- Industrial discharges
- Illegal dumping
- Equipment cleaning
- Stormwater from roads and parking lots


Can I eat the fish?
Eating Columbia Slough fish may be hazardous to your health. The fish may contain PCBs and pesticides, chemicals that may effect human development, reproduction, immune systems, and increase your chance of getting cancer. If you do choose to eat Slough fish it is important to follow these steps:

• Cut off and throw away head, skin, fatty parts, and guts. These are the places where chemicals build up.
• Bake or broil the fish (without skin and fat) on a rack so that the fat drips off. Do not eat fat drippings
• Eat only tail and claws of crayfish
• Do not eat head and guts

Columbia Slough Watershed Facts

The Columbia Slough watershed contains:

* 32,700 acres
* Largest urban wetland in the USA (Smith and Bybee Lakes Wildlife Area )
* Salmon refuge in the Lower Slough
* 175 bird species
* 26 fish species
* 6 lakes, 3 ponds, 50 miles of waterway
* 30 miles of flood control levees
* 158,000 residents (1/20 of Oregon's population)
* 54 schools, 2 universities, 1 community college
* Critical wildlife corridors
* Portland International Airport
* Port of Portland marine terminals
* 3,900 businesses
* 57,000 jobs
* 54% impervious surface
* Columbia South Shore Well Field (drinking water)
* One of Portland's "industrial sanctuaries"
* Critical transportation corridors (I-5, I-205, I-84)
* 250,000 railroad cars per year use its railroad tracks
* The Slough is 303(d) water quality listed
* 6 Golf Courses
* 40 Mile Loop Trail
* Canoe and kayak launches
* 426 acres without sewers
* Whitaker Ponds Environmental Learning Center
* Lewis and Clark expedition sites
* Historic Native American settlement sites