Pierce County completed a supplemental study in March 2020 on how to improve McCutcheon Road East at its crossing with Canyonfalls Creek to protect spawning salmon and mitigate roadway flooding risks.
Pierce County will begin design work on a new crossing once additional information about a potential setback levee along McCutcheon Road East is available.
About the Crossing
Canyonfalls Creek travels down a steep hill before flowing through a shallow channel located beside McCutcheon Road East for about 150 feet. The creek then crosses under the road through a culvert.
Over the years, the creek has deposited sediment into the shallow channel, raising the creek bed elevation. Currently, the creek is at or near the same elevation of the road, with sandbags preventing water from flowing over the roadway. In order to prevent roadway flooding, Pierce County road maintenance crews previously received permits to remove the sediment and lower the elevation of the creek.
Because salmon use the shallow channel to spawn, future permits will not be issued per Tribal treaty rights, and a permanent solution - that does not involve removal of sediment - needs to be identified.
The first study on how to reconfigure the crossing was completed in 2017. A supplemental study was completed in March 2020 after receiving new information from adjacent property owners.
The hydraulic studies have identified a possible design for a new crossing. A new bridge would be constructed where the creek meets the road, requiring the road to be raised.
The creek would flow through a new channel cut into a field located west of the road and reconnect with the existing creek path. The sediment would be deposited in the new channel constructed in the field, reducing sediment build-up. This design may change if the county decides to construct a setback levee along McCutcheon Road East.
Once a proposed elevation is identified for a potential setback levee along McCutcheon Road East, Pierce County will begin design work and identify right-of-way/private property needs. This work will take about six months.
Environmental permitting cannot begin until the 128th Street Comprehensive Setback Levee Feasibility Study is complete. A project to provide a new connection to the Bonney Lake Plateau may impact right-of-way needs. There is currently no funding available for construction or right-of-way acquisitions for the new crossing.