Flights End Restoration Concept Modeling and Alternative Analysis

cbec teamed with Wolf Water Resources (WWR) on this restoration project commissioned by the Columbia River Estuary Task Force (CREST), with support from the Oregon Department of Fish and Wildlife (ODFW) and Bonneville Power Administration.

The Flights End site is within the ODFW managed Sauvie Island Wildlife Area, a floodplain refuge habitat just downstream of the urban waterfront corridors on the Columbia and Willamette Rivers. The project goals and objectives consisted of re-establishing full tidal inundation and juvenile salmon access by removing undersized culverts and artificial earthen berms, lowering marshplain elevations, creating new channel openings, including new channels connecting the wetlands to the Crane Slough. Beaver dam analogues also were installed as habitat features. The project also included installation of a 60-foot bridge.

cbec supported the refinement of the preferred alternative restoration design. To to this, cbec used WWR’s updated field survey data to develop a numerical model for the project area, as adapted from the model previously prepared for the Crane/Domeyer/Willow Bar Restoration Project. The model was used to understand ecological performance of the preferred alternative and refine the design of the alternative’s restoration measures. Also, given the project’s proximity to flood infrastructure, a flood impact or no-rise hydraulic analysis was conducted to demonstrate that the preferred alternative would not result in an impact flood elevations. Building off the design concept cbec analyzed, construction was completed in 2017. The effort restored full fish access to the wetlands directly off Crane Slough and the Multnomah Channel, and created two new channel openings, removed four culverts, installed a channel spanning bridge, and excavated 18,000 cubic yards of soils.

Waterbody / Watershed

Crane Slough, Multnomah Channel, Columbia River

Disciplines