Horsetail Creek Floodplain Restoration, Oregon

Located on the Columbia River floodplain, the 180-acre Horsetail Creek project area was dramatically impacted by construction of Interstate 1-84 and resulting diversions of the creek, as well as a pea gravel mine. Despite this legacy of disturbance, intact portions of Horsetail and Oneonta Creeks were still providing key rearing habitat for local and out-migrating upriver mainstem populations of ESA-listed salmon and steelhead.

Inter-Fluve assisted the Lower Columbia Estuary Partnership in a baseline assessment, fish passage evaluation, habitat and fish passage restoration feasibility study, conceptual and detailed restoration design, development of construction documents, and assistance through project solicitation and implementation. The project was constructed 2013 with aid of a Chinook helicopter for transporting and placing large wood.

Portland General Electric (PGE) and Inter-Fluve received an American Council of Engineering Companies (ACEC) Engineering Excellence Honor Award in spring 2016 for the project.

A Chinook helicopter transports large wood at the Horsetail site. Over 700 logs were used.

Enhanced channel segment in lower Oneonta Creek at high water.

The enhanced channel segment 16 months later at low water.

Complex construction sequencing involved the US Forest Service, ODOT, Cascade Locks Electric, Union Pacific railroad, and many regulatory entities with jurisdiction over the area.

The project is a model for implementing complex floodplain and stream restoration in an area that was heavily impacted by both construction of an interstate and railroad.

Six years after construction.