Upper Abernethy Tributary Restoration Design

This project location is within the upper Abernethy creek basin along an unnamed tributary flowing into reach 3 of the main channel. An Upper Abernethy Creek Rapid Bio-assessment conducted in 2019 and the 2021 Strategic Restoration Action Plan for Native Fish in the Abernethy Creek Watershed identifies the need to improve habitat complexity, reduce fine sediments, improve pool habitat, reduce stream temperature and provide future supplies of large wood. The Upper Abernethy Tributary Restoration project will design improvements to instream and riparian conditions along 2,002-feet of stream channel in an unnamed tributary to upper Abernethy Creek. Extensive blackberry coverage risks compromising the remaining riparian area as it spreads along the stream channel. Cool water temperatures in summer can be protected and even improved through the removal of invasive blackberry, maintenance of the invasive vegetation removed, and planting of appropriate riparian plants/trees for the area. Project partners include NOAA Fisheries through an Infrastructure and Investment Jobs Act grant provided to Johnson Creek Watershed Council, the Clackamas Partnership, and the private landowner.

Within the upper Abernethy portion of the watershed, restoration projects are being undertaken along multiple reaches of the main stream and tributaries to address a lack of habitat complexity by increase the quantity and quality of in-stream large wood, reduce impacts of invasive blackberry and other non-native plants, and restore riparian forests.

This project will specifically develop design and engineering documents to support restoration of over 2,000 feet of in-stream habitat, 2.5 acres of riparian forest, and address 6 limiting factors for coho salmon, winter steelhead and Pacific lamprey including: Altered hydrology, physical habitat quality (fine sediment retention, degraded riparian habitat, degraded channel structure, invasive species) and water quality (elevated stream temperatures).

The Upper Abernethy Tributary Restoration project will recruit a skilled design and engineering team to work with the watershed council and partners on the development of an engineering design, construction documents, a monitoring plan, and conduct all necessary required actions to facilitate permitting. Additionally, this technical assistance proposal will support development of a request for proposals to recruit a qualified and experienced construction firm capable of implementing the design.

The design and engineering process will include the following key steps/phases 1) 30% design development, 2) 60% permit-level designs, 3) permit application, 4) final design, 5) construction observation and field fit activities. Each task will provide opportunity for qualified reviewers supporting the councils technical assistance committee to provide input and refine the project outcomes to best benefit coho, steelhead, and lamprey. This work will be informed by data and observations collected in the upper Abernethy watershed during the past decade and contained within several technical reports supported by the councils work.