A GEOECOLOGICAL INVESTIGATION OF NEWELL CANYON, OREGON CITY, OREGON

Newell Canyon is an 1800 acre urban watershed in southeast Portland, Oregon. Clackamas County, the city of Oregon City, and Metro are the 3 governing bodies trying to make land use decisions about the canyon, one of the last urban greenspaces in the region. We have been studying the canyon for over 10 years with students to gather information to help the decision makers. Our approach has been based on geoecology where we collect data on abiotic and biotic processes and then study their interaction within the watershed. Sound management decisions are derived from all 3 areas. Studies have covered the distribution of soils, landslides and wetlands, the geology of the canyon (Boring Fm. basalt covering the uplands surrounding the canyon and Troutdale Fm. fluvial sediments within the canyon), reaches of the streams, storm water input, wildlife inventories, forest inventories, wildlife corridors, and trails. Decisions have to be made about housing development, trail development, and storm water settling ponds. Before they can be arrived at, layers of information from the biotic side (fish, forest and beaver habitat) must be combined with the geologic habitat (stable soils and landslides) and stream and wetland habitats. The beaver ponds provided for important sediment collection to preserve fish habitat in the reaches below. Quality fish habitat and beaver pond reaches have been excluded from trail development. Slopes with ancient landslides have been excluded from housing development. All decisions are based on the interaction of fish, forests, geology and streams.