DESCRIPTION
The purpose of the project is to consider restoration alternatives and create a preliminary design that will restore fish access to one mile of stream in the upper Dickerson Creek watershed, install woody material to increase habitat complexity, aggrade the stream channel, and improve floodplain connectivity. The project would be designed to meet requirements of Manual 18 Appendices D-1 and D-2.Approximately 750 ft. of Dickerson Creek flows through the Carpenter, Fleming, and Ruiz parcels and restoration design is proposed for approximately 2.5 acres of riparian and floodplain area. The project will benefit wild Steelhead, Coho, Chum, and Cut-throat spawning and rearing habitat. Dickerson Creek is a tributary to Chico Creek, which is one of the highest priority salmon streams in Kitsap County identified by the West Sound Lead Entity and Suquamish Tribe. Prior 2007 log weirs were installed to improve fish passage and maintain grade, however, erosion and flooding washed out the weirs and caused three 33% fish barriers, located on the Carpenter property. These barriers limit fish access to approximately one mile of high quality spawning and rearing habitat. The design will also address removing roadbed fill in the floodplain and look at developing side channel habitat. A noxious weed removal and planting plan will be developed.
This project addresses actions D2 and D3 in the Chico Creek Watershed Assessment for the Identification of Protection and Restoration Actions (2014).
This project involved development of an alternatives report outlining the design approach and identification of 3 restoration alternatives and completion of a preliminary design. This deign will restore fish access to one mile of stream in the upper Dickerson Creek watershed, install woody material to increase habitat complexity, aggrade the stream channel, and improve floodplain connectivity. Approximately 750 ft. of Dickerson Creek flows through the Carpenter, Fleming, and Ruiz parcels and restoration design is proposed for approximately 2.5 acres of riparian and floodplain area. Implementation of this design will benefit wild Steelhead, Coho, Chum, and Cut-throat spawning and rearing habitat. Dickerson Creek is a tributary to Chico Creek, which is one of the highest priority salmon streams in Kitsap County identified by the West Sound Lead Entity and Suquamish Tribe. Prior to 2007, log weirs were installed to improve fish passage and maintain grade, however, erosion and flooding washed out the weirs and created three 33% fish barriers, located on the Carpenter property. These barriers limit fish access to approximately one mile of high quality spawning and rearing habitat. The design also addresses removing roadbed fill in the floodplain and channel meandering and raising the grade of the incised channel.
Design bid materials were developed and bids solicited to contract with an Engineering/Design firm. Natural Systems Design was chosen to complete the deliverables. Conservation District staff conducted meetings with landowners, US Navy and other stakeholders. Stakeholder input and not negatively impacting passage to the Navy Rail Road were considered in the initial design concept.
A Concept Design Evaluation report was completed highlighting three alternatives for consideration. This report was distributed to permit agencies, US Navy, landowners, and the SRFB review panel. Alternatives 2 and 3 were supported by the SRFB review panel, and a revised version of Alternative 3 was taken to the preliminary design stage. Agency input and budget were factors in modifying the 3rd alternative that was taken to preliminary design. This design meets requirements of Manual 18 Appendices D-1 and D-2.
Preliminary Design Objectives
The project goal is to develop a design plan that:
1. Corrects the fish passage barrier present at the oversteepened knickpoint in which a headcut has migrated upstream to the upper log weir on the Carpenter property.
2. Removes artificial fill confining the channel and materials associated with the failed weirs;
3. Restores geomorphic function with placement of large woody material; and
4. Restores riparian processes with removal of noxious weeds and planting of native trees and shrubs.
Specific objectives of the channel design include:
1. Regrade the channel profile to a more uniform slope that removes the knickpoint forcing the fish passage barrier;
2. Provide resilience to future channel adjustments (vertical and horizontal);
3. Reconnect or create a floodplain surface adjacent to the channel that is inundated by overbank flow at a relatively common frequency (1- to 2-year recurrence interval flow);
4. Increase pool frequency and depth to provide holding areas for adult salmonids to rest during upstream migration;
5. Provide low-velocity habitat with complex cover to create rearing habitats for juvenile salmonids; and
6. Increase wood loading to match frequency observed in streams with functional riparian processes using the 75th percentile of reference values from Fox and Bolton (2007) or greater than 63 pieces per 100 m.
Additionally KCD completed a planting plan to accompany the plan.