• Study

SR 20 Skagit O'Brian Reach Feasibility Study

Planning study news

In 2020, WSDOT received a Salmon Recovery Funding Board (SRFB) grant to find a long-term solution that reduces flood and erosion damage to State Route 20 from the Skagit River during floods, and improves native fish habitat within the river and its floodplain.

The study team has documented existing floodplain processes and habitat conditions in the watershed and presented them to stakeholders and community members during a virtual community workshop in November 2022. The team solicited input on development of project alternatives and evaluation criteria and are refining the draft evaluation criteria.

Currently, the study team is developing alternatives based on these criteria and will evaluate existing conditions against two potential alternatives using a hydraulic model to predict expected future conditions, and then apply the evaluation criteria.

A second virtual community workshop will be held in spring 2023 to review results of the analysis and solicit input on a preferred alternative concept.

Timeline
January 2022 - December 2023
Status
In progress
Budget
$275,000

Purpose

The SR 20 Skagit River O’Brian Reach Feasibility Study study area is located along SR 20 near Rockport at milepost 101 (near Cascade Farms). The purpose of the study is to identify a project concept that will:

  • Reduce erosion and flood damage to SR 20 during frequent flood events, which often result in the need for emergency repairs and highway closures.
  • Improve degraded fish habitat in the Skagit River and its floodplain by enhancing the connectivity of side channels and floodplain habitats to the river during small and medium-sized floods.

The feasibility study is a collaborative and integrative approach to address a recurring problem on a state highway in a large river basin with a great deal of conservation interest. The primary objectives of the study include:

  • Engage early with stakeholders and potential future project partners.
  • Understand and communicate habitat conditions and floodplain processes in the O’Brian Reach and factors that cause bank erosion and flooding.
  • Develop several fish-friendly project concepts that reduce the force of high river flows on the highway embankment and improve floodplain connectivity and habitat for native salmon and steelhead.
  • Select a feasible project concept, with input from stakeholders in the basin.
This map shows the Skagit O'Brian Reach study area located along SR 20 between Rockport and Marblemount in Skagit County.