Tryon Creek Fish Passage Restoration Alternatives Study

Tryon Creek Fish Passage Restoration Alternatives StudyHENDERSON environmental planners, stream restoration ecologists, watershed analysts, and graphic designers were selected by the City of Lake Oswego, Oregon to build consensus within a multi-agency Partnership of local, state and federal resource and transportation interests for the removal of an existing culvert on Tryon Creek beneath Hwy 43.  HENDERSON provided the primary leadership and technical expertise in building consensus within the Partnership for consideration of design alternatives developed through this Study.

Future implementation of the Partnership’s preferred Study alternative would result in the restoration of Tryon Creek from the Willamette River through the 645-acre Tryon Creek State Natural Area Park.  The Oregon Department of Fish and Wildlife has prioritized removal of the existing fish passage barrier as one of the greatest opportunities in Oregon to re-extend significant fish habitat into a local watershed.  Restoration would reconnect approximately eight miles of Tryon Creek to year-round passage of fish and other aquatic species, improving in-stream and riparian habitat for fish and wildlife.  US Fish and Wildlife Service’s Habitat Improvement Program funded this Study.

Study design elements prioritized by the Partnership included improvement of passage of targeted fish species, primarily salmonid and lamprey, between the lower and upper reaches of Tryon Creek and provide year-round fish passage to other native species during all life stages.  Enhancements of riparian habitat and watershed connectivity for indigenous wildlife and providing public recreational access with passage beneath Hwy 43 were also key objectives for design alternatives considered.  With our design-build expertise, HENDERSON’S unique ability to provide cost estimation and value-engineering of alternative concepts being considered greatly helped to focus the Partnership’s final selection of a preferred design concept.

Old-timers tell about a time decades ago when the creek ran thick with coho salmon, steelhead and cutthroat trout.  Today, fish experts believe salmon have trouble jumping into the Tryon Creek culvert from the plunge pool on the downstream side.  “The culvert is a major barrier to fish migrating upstream,” says Ronald Kroop, regional manager for the Oregon Department of Transportation.  ODOT and other local, state, and federal resource agencies have joined in a partnership to improve the culvert and improve fish passage’
– The Oregonian

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