Laura McMullen
ICF
Greg Blair
ICF
Lisa Spurrier
Pierce County
This assessment was to inform an update of the Salmon Habitat Protection and Restoration Strategy (the Strategy) through a quantitative evaluation of progress made, and potential for future progress towards restoration of anadromous salmonid habitat in the Puyallup/ White and Chambers/ Clover Watersheds. A salmonid habitat model, Ecosystem Diagnosis & Treatment, was used to evaluate habitat for Chinook salmon, coho salmon, and steelhead trout. Scenarios evaluated included historic conditions, 2003 conditions, current (2020) conditions, and future conditions that considered maturation of recent restoration actions to their full benefit.
Overall, while salmonid populations in the Chambers-Clover and Puyallup-White watersheds are significantly reduced in their abundance and diversity as compared to their historical conditions, we found that habitat restoration projects completed since our original analysis in 2003 have significantly improved habitat and access to habitat.
Significant improvements to habitat potential for all species has been due to projects in the Clearwater and Greenwater rivers in the Upper White River, restored flows in the lower White River between the Cascadia Water Alliance diversion dam at Buckley (RM 24.3) and RM 3.6, elimination of the TPU pipeline crossing barrier in the lower White River, and the Countyline floodplain restoration project in the lower White River. Additional significant improvement to habitat potential has been due to restoration in South Prairie Creek, and several levee setbacks, and floodplain restoration projects on the Puyallup River.
Looking forward, restoration of mainstem areas and large tributaries is predicted to result in the most potential improvement for Chinook populations in the Puyallup-White watershed, with actions designed to increase the quantity of juvenile rearing habitat and improve habitat complexity eliciting the greatest benefits. These objectives can be achieved through strategies to reconnect waterways to their historic floodplains and off-channel features, add large wood and increase pool-riffle complexity, and enhance riparian areas. We found that strategies identified in the “Salmon Habitat and Restoration Strategy for Puyallup and Chambers Watersheds” (2018) closely aligned with our assessment.