Issaquah Creek In-stream Restoration

The Mountains to Sound Greenway Trust will complete final designs and permitting and construct Phase 1 of a habitat restoration project along ~3,165 feet of Issaquah Creek in Lake Sammamish State Park. Within the project area the creek is incised in many locations, with moderate to high flows confined to a primary, single-thread channel without high-flow refugia. The goal of the project is to restore natural habitat forming processes to improve juvenile rearing habitat for Chinook and other salmonids by connecting the creek to its floodplain, increasing off-channel habitat, improving in-stream habitat diversity and complexity by adding large wood, and enhancing riparian buffers and wetland habitat. This phase of the project targets restoration of Reaches 2 and 3 as described in the attached Preliminary Design Report in PRISM. the Greenway Trust will also install an interpretive sign to educate park visitors about ways they can support salmon recovery. In addition to advancing recovery of ESA-listed Chinook, this project seeks to increase salmon populations to feed ESA-listed Southern Resident Orcas.
This project continues the work underway between the Greenway Trust, State Parks, and other partners, and builds upon 15+ years of riparian habitat restoration. When all phases of the overall restoration project are funded and constructed, more than 6,500 feet of Issaquah Creek in Lake Sammamish State Park will be restored. Final Designs will meet Manual 18 Appendix D-3.
In August 2021, a cost increase amendment added $631,983 of 2021-23 PSAR funding awarded by WRIA 8 during the 2020 SRFB grant round to afford the full scope of work described herein.
The 2018 PCSRF was expended before the end of the PCSRF award.

Enhance the quality and quantity of key, strategically located salmonid habitat, particularly for juvenile Chinook rearing and adult Chinook holding in Issaquah Creek to support WRIA 8 Salmon recovery goals. Adding large wood to the creek will create a suite of low-velocity habitats promoting longer stream residence. The hydrology of the system will engage the floodplain, and the LWM will scour out pools. Increase in refuge areas will result in longer periods of rearing, helping fish achieve greater fitness and condition. Riparian reforestation will provide future LWM recruitment, shade the creek, provide additional nutrients, and other benefits. TIMING OF FISH USE
Juvenile Chinook Use: Reared hatchery fish will be utilizing the habitat primarily from late April to mid-May, whereas natural fry will use the habitat beginning in February. Chinook will stay in the system typically into June. Adult Chinook: early September through the end of November.
Adult Sockeye: August through October
Adult Coho: October through December
Adult Kokanee: November through January.