Mr. Gorman provided hydraulic modeling and design support to the Portland Bureau of Environmental Services for improvement of fish passage, streambank stabilization, and in-channel habitat quality enhancements for the Tryon Creek Trunk Sewer Upgrade project in Lake Oswego. Tryon Creek represents a fairly uncommon but productive habitat type along the Willamette River used for spawning, foraging, and high-flow refugia by sensitive aquatic species. ODFW listed Tryon Creek as its highest priority for fish passage restoration in Western Oregon. Two significant fish passage barriers exist within the Trunk Sewer Upgrade reach of the creek. Mr. Gorman designed naturalized fish passage step pool systems to be constructed through excavation within the bedrock substrate of the stream channel and the addition of large rock to enhance fish passage while minimizing a rise in the Base Flood Elevation. He also designed streambank stabilization prescriptions for an eroding bank that is threatening the structural integrity of the Trunk Sewer.
Tryon Creek Trunk Sewer Upgrade and Fish Passage Design – Lake Oswego, Oregon
