Project Overview
As part of a larger response to a legal injunction for upgrading hundreds of fish barriers across the state, PND designed two new fish passages at Trafton Creek and Schoolyard Creek under State Route 530 in Northwest Washington, both spanning over 20 feet. PND supported the complex construction staging required to reduce public and environmental impacts. Throughout design and construction, PND met with members from the Tulalip and Stillaguamish tribes to invite their input on a creative solution to fulfill both the tribes’ expectations and the Washington State Department of Transportation contract. Our design minimized impacts to wetlands, private properties, and the traveling public, while maximizing fish habitat improvements by using stream alignments and large woody material features to increase channel complexity.
Both culvert replacement and fish passage improvement projects were designed within budget, with Schoolyard Creek completed a year early and Trafton Creek completed on schedule. The new passages opened an additional 6.3 miles of habitat and spawning grounds for multiple species of salmon and trout.
Our Role
- Permitting: collaborated closely with the client to secure National Environmental Policy Act (NEPA) and State Environmental Policy Act permits, prioritizing fish habitat expansion and enhancement while expediting the project timeline with an early NEPA submission
- Hydrology & Hydraulics: designed stream simulation for two new fish passages
- Civil Engineering: designed a corrugated metal pipe culvert and concrete box culvert, minimizing impacts to wetlands and traffic through innovative planning
- Construction Support Services: conducted complex construction staging to reduce public and environmental disruption
Creating Harmony Between Environmental and Community Needs
PND prioritized environmental stewardship during design and construction for the corrugated metal pipe culvert at Trafton Creek and the concrete box culvert at Schoolyard Creek. We reduced impacts to Schoolyard Creek and its surrounding wetlands by reducing the fill footprint of the temporary vehicle bypass, steepening embankments to reduce culvert length, and strategically planning to avoid cutting trees during construction. At Trafton Creek, we minimized the construction footprint by steepening the embankment slopes and using reinforced soil slopes, greatly reducing impacts to travelers and local homeowners while accelerating the construction schedule. Throughout design and construction, we consistently reduced environmental impacts by leaving the project site as close to preconstruction conditions as possible.
“PND was a joy to work with. They consistently provided deliverables on time or ahead of schedule. They stayed engaged in the project throughout the duration for the contract by providing timely responses to questions and RFIs during construction to ensure the work wasn’t impacted. They helped strengthen the client’s relationship with stakeholders throughout the process.”
Fish Species
can now spawn and rear in an improved habitat
Miles
of new habitat are now open to fish
