Planning and conservation › Natural areas, parks and trails › Protecting natural areas › Acquiring natural areas › Columbia Slough
Learn about the goals and objectives for habitat and water quality protection in the Columbia Slough target area. View maps illustrating the Metro Council's priorities in this area and learn more about the importance of the area to our region.

Tier I Objectives
Tier II Objective
The Columbia Slough is a 19-mile long remnant of lakes, wetlands and slow-moving channels in the southern floodplain of the Columbia River. It stretches from its origin at the 102-acre Fairview Lake and the headwaters of Fairview Creek near Grant Butte in Gresham westward to the 2,000-acre Smith and Bybee Wetlands Natural Area and to its confluence with the Willamette River.
The lower slough is free-flowing, but most of the slough is contained within a system of levees and floodgates and is managed by local drainage districts. Historically, the slough absorbed flood waters from the Columbia River, but in the early 1920s levees were constructed to prevent seasonal flooding and the waterway was transformed into the channeled and highly managed system now known as the Columbia Slough. Today, the nearly 40,000 acres of lands that drain to the Columbia Slough are heavily urbanized containing 24,000 homes and 4,500 businesses including commercial and industrial uses, the Portland International Airport and several golf courses.
With development and altered water circulation, the Columbia Slough experienced serious water quality decline. However, since the elimination of Combined Sewer Overflows in 2000, and watershed-wide restoration efforts, the slough is cleaner today than it has been in more than 100 years.
In spite of its urbanized character, the Columbia Slough contains surprising wildlife and plant diversity. Mammals such as deer, beaver and river otter are common along the slough, and about 175 bird species have been documented in the watershed.
Efforts are underway to close gaps in the Columbia Slough segment of the 40-Mile Loop, develop neighborhood connections to local and regional trails and increase access for paddlers on the slough.
The Columbia Slough is one of very few areas in North and Northeast Portland with the potential for restoring fish and wildlife habitat. Acquisition along the slough will improve water quality in its critical reaches, provide trail connections to existing recreation areas, secure wildlife corridors and help complete an important section of the 40-Mile Loop.
In September 2007 the Metro Council approved acquisition plans for each of the 27 regional target areas. The Metro Council established these priorities with the input of natural resource and land use experts, scientists, citizens and local land managers. More than 500 people attended eight community open houses to share their ideas with Metro Councilors. Nearly 1,000 people filled out questionnaires ranking their priorities and offering ideas for partnerships and other ways to stretch the public's investment. The acquisition plans include a map, goals and objectives for each target area.
Natural Areas Program
503-797-1545
naturalareas@oregonmetro.gov
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