Several of our projects that maintain a neighborhood’s flood protection, improve water quality for a diverse south Seattle community and Elliott Bay, and enhance King County’s vast regional trail system have received national recognition for innovation.
The America Council of Engineering Companies (ACEC) honored professional firms that partnered with the Department of Natural Resources and Parks on a variety of significant construction projects that help the department fulfill King County’s Clean Water Healthy Habitat commitment.
East Lake Sammamish Trail
Consulting firm Parametrix received the ACEC’s “National Gold Award – Special Projects” for its longstanding collaboration with King County Parks’ development of the East Lake Sammamish Trail. The trail, completed in October 2023, follows the lakeshore for 11 miles through Redmond, Sammamish and Issaquah, and connects to other regional trails, major parks and open space areas, light rail, and more.
Parametrix began working with King County in 1998 on master planning for the trail within the former railroad right of way, leading a region-wide community engagement effort to guide development.
The firm worked with King County on all phases of the project – from master planning and grant preparation, to permitting, design, and finally construction, all while overcoming challenges that ranged from multiple lawsuits and permit appeals, to coordinating work with multiple jurisdictions.
Crews planted roughly 4,700 trees and 98,000 low-maintenance native shrubs, and wetland mitigation work was done across 10 acres. Eleven fish passage culverts were constructed, including on streams where the county and partners have worked to restore rare Lake Sammamish kokanee salmon.
The trail was built to the same high standards as the rest of our Leafline regional trail system. The East Lake Sammamish Trail connects neighborhoods, communities and cities across King County with industry-leading design and construction practices that result in recreation opportunities for all.
Georgetown Wet Weather Treatment Station
Jacobs Engineering Group won the “Best in State – Gold Award” for innovative use of new or existing techniques as part of its work on the Wastewater Treatment Division’s recently completed Georgetown Wet Weather Treatment Station in south Seattle.
Located at the corner of 4th Avenue and South Michigan Street in Seattle’s Georgetown neighborhood, our Wastewater Treatment Division’s latest clean-water investment can treat up to 70 million gallons of combined rain and wastewater a day that would otherwise discharge directly to the Duwamish River during heavy storms.
Before the station was completed in 2022, heavy rains would fill up the area’s sewer pipes, sending polluted runoff and sewage through a pipe into the river. The new treatment plant was designed and constructed to withstand 2 feet of sea-level rise, ensuring its clean-water attributes will last well into the future.
Jacobs and its partners led the engineering effort while collaborating with WTD staff, the community, and key stakeholders to deliver a project that is a vital public asset for water quality improvement.
The treatment station uses advanced technology and wastewater treatment processes, including flow equalization, ballasted sedimentation and ultraviolet disinfection, to ensure the plant effectively treats combined stormwater and wastewater during the wet season while operating on a very small facility footprint.
The Georgetown station has already prevented an estimated 32 million gallons of polluted stormwater and wastewater from reaching the Duwamish River and Elliott Bay. The capital project represents a culmination of technical innovation, sustainable design, and community engagement and education of the environment.
Jan Road Levee Setback
Contractor Tetra Tech won the “Best in State – Silver Award” for its work on our Water and Land Resources Division’s Jan Road Levee Setback project along the Cedar River in Maple Valley, recognizing the project’s “future value to the engineering profession and perception by the public.”
Completed in 2022, our King County Flood District-funded project rebuilt and strengthened flood-reduction infrastructure for a neighborhood of 15 homes with a sole access roadway that was prone to flooding during moderate or higher flood events on the Cedar River and nearby Taylor Creek.
Project elements included removing the old, degraded levee and building a new levee farther back from the river. Setting back the levee gives the river more room to spread out, helping to reduce erosive force and creating a more natural river course.
Using innovative design features were an alternative to a traditional large rock structure along the bank of the Cedar River Trail that would have required reconstructing the streambank, including removing mature trees that provide shade and offer other benefits for fish and wildlife.
A major feature is the construction of a side-channel and buried log structures to provide habitat and stability. Just weeks after the work was completed, county ecologists documented Chinook salmon spawning in the new side channel – a remarkable indication of the project’s success of improving habitat for fish and wildlife, while maintaining flood protections for people and important infrastructure.