Upper Abernethy Creek Oregon City, Oregon

Adding nearly 300 pieces of large wood using a unique helicopter installation approach, the restoration of Upper Abernethy Creek created new habitat for a variety of species while also encouraging natural growth of the watershed. In leading the design, Otak utilized hydraulic modeling to optimize features in the reach for variable future conditions.

Unique Approach Adding Large Wood to Restore a Watershed

Located in the Port Blakely timber lands, the design for Upper Abernethy Creek enhanced floodplain connectivity in the area with placement of large wood in the watershed. Use of a heavy-lift helicopter facilitated access in difficult terrain while also reducing or eliminating impact to the natural environment. The project dramatically increases the number of key wood pieces, both by direct addition and in bolstering future wood recruitment. These structures provide cover over the stream channel and scouring for pool creation that supports aquatic organism habitat and spawning conditions. It also improves sediment trapping and sorting while encouraging remeandering of ditched and straightened reaches. Critical design features included 2D hydraulic modeling to confirm flood flow depths in the channel and across the floodplain which informs minimum sizes for unanchored wood pieces and attached rootwads.