For more than a decade, the Watershed Manage-ment Division of the City of Gresham, Ore., looked for ways to deal with runoff from an 800-acre industrial and commercial site. This untreated water flowed from parking lots and streets directly into the Columbia Slough. The slough consists of 60 miles of waterways, wetlands and slow-moving channels. It feeds the Columbia River, and provides salmon-rearing habitat and a favorite place for canoers and kayakers. The ultimate solution was to build an engineered wetland. Several factors converged to make the Columbia Slough Regional Stormwater Treatment Facility happen. They included a donation of valuable
