Lewis Creek
Lewis Creek runs beneath I-90, Southeast Newport Way and West Lake Sammamish Parkway Southeast near Lakemont Boulevard Southeast. It serves as a tributary to Lake Sammamish. The culverts under I-90 are completely impassable. The creek is home to chinook, coho and sockeye salmon and steelhead, sea-run cutthroat and resident trout. Replacing the existing culverts with new fish-passable structures will result in a potential habitat gain of 2.7 miles.
As part of this work, WSDOT will build a new roundabout on Southeast Newport Way and relocate the I-90 eastbound on-ramp. Work at this location is expected to last about two to three years.
Expected traffic impacts due to phased construction
- I-90 – lane reductions
- Southeast Newport Way –lane reductions
- West Lake Sammamish Parkway Southeast – temporary full closure
West Village Park & Schneider Creeks
West Village Park Creek runs under I-90, Southeast Newport Way and West Lake Sammamish Parkway Southeast. As a tributary to Lake Sammamish, the West Village Park Creek is home to coho salmon, steelhead, sea-run cutthroat, and resident trout. The culvert carrying the creek is currently completely impassable. Fish barrier correction would result in a potential habitat gain of approximately one-half mile.
Schneider Creek is located near the west edge of Lake Sammamish State Park. The creek runs under I-90 and Northwest Sammamish Road. Schneider Creek is home to coho and sockeye salmon and steelhead, sea-run cutthroat, and resident trout. Fish barrier correction would result in a potential gain of approximately 0.7 miles of new habitat.
Construction of the new fish passable structures is expected to last up to three years.
Fish barrier correction will combine both creeks into one crossing location by rerouting West Village Park Creek into Schneider Creek. A new stream channel would be created along I-90 and within Sammamish Cove Park.
Expected traffic impacts due to phased construction
- I-90 – lane reductions
- Southeast Newport Way – temporary full closure
- Northwest Sammamish Road – temporary full closure
Unnamed Tributaries to Tibbetts Creek
The Unnamed Tributaries (UNTs) to Tibbetts Creek location is a collection of barriers near the interchange of I-90 and SR 900/17th Avenue Northwest. The Unnamed Tributaries to Tibbetts Creek run beneath I-90, an off-ramp and several on-ramps. The Unnamed Tributaries to Tibbetts Creek are home to coho and sockeye salmon and steelhead, sea-run cutthroat and resident trout.
Construction of the new fish passable structures is expected to last up to four years.
Construction of the 11 new fish passable structures is anticipated to last up to four years.
Expected construction impacts
- I-90 – lane reductions
- I-90 eastbound on-ramp – temporary full closure
- I-90 westbound off-ramp – temporary full closure
- I-90 westbound on-ramps – lane reductions
- Northwest Gilman Boulevard – lane reduction
Tibbetts Creek
Tibbetts Creek runs under SR 900 at milepost 19.5, north of Squak Mountain State Park. The existing culvert is considered one-third passable, making it difficult for coho and sockeye salmon and steelhead, sea-run cutthroat, and resident trout to successfully navigate up and downstream. Fish barrier correction would result in a potential habitat gain of more than one mile.
This work is expected to last up to one year.
Expected construction impacts
- SR 900 (Renton Issaquah Road Southeast) – temporary full closure