DESCRIPTION
The City of Seattle used this funding to complete a site analysis to determine the feasibility of relocating and restructuring the levee system to increase and improve fish habitat on the lower Tolt River. Project area is the lowest mile of the Tolt River, to the confluence with the Snoqualmie River used by Snohomish fall Chinook, coho, chum and steelhead. Seattle City Light 1) developed a conceptual design for levee setback and removal that will allow the channel to meander unconstrained, without decreasing the level of flood protection provided by the existing levees; and 2) quantified increases and improvements in Chinook spawning and rearing habitat that would occur as a result of the project.
The lower Tolt River is one of the most constrained sections of river in the Snoqualmie Watershed. The Tolt Floodplain Reconnection Project would increase spawning habitat for Chinook salmon, increase protection of Chinook salmon redds by reducing scour, and increase rearing habitat for all native salmon and trout using the lower Tolt River. The future restoration project involves setting back or removing levees that currently constrain the channel, reconnecting the river to the main channel, historic side channels and a wetland at the mouth of the river. This reconnection is expected to enhance abundance, diversity and distribution of Chinook, coho, chum and steelhead within their historical range.