By Keith K. Daellenbach | Contributing Writer
For all the parks in Portland’s metropolitan area, one large open space flies below the radar as if it were a secret, the Columbia Slough. This watershed is 32,700 acres in size and supports a large wetland habitat stretching from Troutdale to North Portland. It looms large in our neighborhood’s collective consciousness, always present but largely unknown and seemingly impenetrable.
At its heart is a slow-moving stream corridor that flows east-towest and parallel to the Columbia River connecting neighborhoods, natural areas, and industrial lands. It is a vital part of the Lower Columbia Estuary as one of 28 estuaries in the EPA’s National Estuary Program.
170,000 people including those in the Concordia neighborhood, or four percent of all Oregonians, call the watershed home. However, 95 percent of these residents live upland of the slough and are, in a way, separated from the slough itself by N.E. Columbia Boulevard. The slough connects to multiple segments of the 40-mile loop and regional trail system, now 70 percent completed, for pedestrians and bicyclists linking parks, open space, and vehicle-free trails.
The Urban Flood Safety and Water Quality District (UFSWQD) is a special district under the Oregon statute that operates and maintains the 27 miles of levees, including the primary levee along the northern boundary of the slough along Marine Drive and 12 pump stations. According to UFSWQD, the slough has 40 miles of slough and stream waterways.
According to the 40-Mile Loop Land Trust compilation, which does not account for riparian habitat immediately adjacent to primary and secondary streams, the Columbia Slough contains 2,560-acres of natural habitat in no less than 12 publicly owned open spaces. If the slough were a park, it would be the second largest park in metropolitan Portland behind Forest Park (5,200 acres) and ahead of Tryon Creek State Natural Area (658 acres).
In the slough, although not adjacent to the primary waterway, is the delightful City of Portland’s 27-acre Columbia Children’s Arboretum (10040 N.E. 6th Drive). This article series seeks to connect residents to the slough, reveal historical, cultural, and natural history perspectives, as well as how to access, recreate in, and, ultimately, protect the slough.
Keith Daellenbach is a mechanical engineer and outdoor enthusiast who loves mountain climbing, skiing, biking, canoeing, and beekeeping with his wife Amy and son Micah.