Clearing paths for fish to coexist with human-made development is an increasing priority across the U.S., particularly in the Pacific Northwest, where the recently completed Meadowdale Beach Park and Estuary Restoration Project is an example of a railway and a municipality collaborating for environmental and sustainability solutions.
Hanson assisted Snohomish County, Washington, with this culturally and environmentally significant project, born from a need to address the combined challenges of safe and reliable beach access, flooding, maintenance, fish passage, sediment transport and habitat loss. Hanson provided railway, civil and structural engineering; permitting; construction management and phasing; and grant writing.
Hanson contributed bridge design and construction management for the approximately $16 million Meadowdale project in Snohomish County, Washington, including a 130-foot-long railroad bridge along Puget Sound.
Historical, cultural and environmental significance
The 108-acre Meadowdale Beach Park, 24 miles north of downtown Seattle, sits adjacent to the Puget Sound Delta and Lunds Gulch Creek, which flows through the park. The park receives an estimated 65,000 visitors and hosts several environmental and recreational education programs annually. The land’s rich history includes occupation by the Coast Salish people and eventual ownership by the Great Northern Railroad, which built its first track in 1891 and became BNSF Railway Co. much later. The region’s logging industry later necessitated the addition of a second track. By 1968, Snohomish County had acquired the property, and in 1988, the county opened the park and signed a BNSF agreement that allowed the public to access the beach through a box culvert passing under the tracks, which separates the beach from the park area.
The connection between Lunds Gulch Creek and Puget Sound, known as a barrier embayment, is historically, culturally and environmentally significant. Embayments are protected estuaries and lagoons that play a major role in providing passage for anadromous salmon and trout migration. They also serve as essential rearing grounds for juvenile fish and enable natural sediment transport. The Coast Salish people cherished the embayments as a place to fish for the food that would nourish and sustain their families.
When the railroad’s embankments were built in the late 19th century, many stream crossings were restricted to culverts sized to maintain drainage and prevent flood impacts. An unintended consequence of this was the blockage of the embayments and the degradation of habitat quality due to Embankment construction led to the loss of most of the embayments along the eastern shore of Puget Sound.
Since the park’s opening, the location of the BNSF-owned double tracks limited beach access to the 6-foot-by-6-foot box culvert, which park visitors had to share with passing stream water and fish. In addition to the environmental impacts noted above, the culvert created an access challenge for park users, some of who resorted to trespassing over the railroad tracks when the culvert was inaccessible due to high stream flow, which was illegal and dangerous. Americans with Disabilities Act (ADA) accessibility was nonexistent, even under the best conditions.
A major aspect of this project for Snohomish County and other local stakeholders was to restore the estuary and improve fish mobility.
Bridge opens access for fish, park users
Hanson contributed bridge design and construction management for the approximately $16 million project, including a 130-foot-long railroad bridge along Puget Sound. Replacing the undersized culvert and 128 linear feet of railroad embankment with a five-span rail bridge featuring a 100-foot opening allowed juvenile salmon access to a pocket estuary where they can grow. A pedestrian walkway under the bridge also provided park users much-improved, ADA-compliant access to the beach from the park.
In addition to the bridge, a major project goal for Snohomish County and other local stakeholders was to restore the estuary and improve fish mobility in the area. The project team overcame a variety of challenges, such as a yearlong construction delay due to wildfires in California, to produce an efficient and environmentally conscious design. The project resulted in the enhancement of more than 500 feet of stream, habitat and riparian buffers; a stream channel widened from at the culvert, increasing its complexity by allowing water and sediment to flow freely, preventing floods and restoring ecosystem processes; and converting park lawns prone to flooding into a high-functioning, 1.3-acre estuarine habitat.
The site is also used for environmental and recreational education programs, and priority was placed on providing new interpretive signs, a picnic shelter, a bathroom area and updates to the park ranger’s residence.
Success for salmon and the ecosystem
According to Hanson Project Manager Laura Vied, P.E., salmonid fish were seen moving up the creek within days of the project team removing the stream bypass and opening the temporary starter channel. “I spotted what was either a trout or salmon resting behind a boulder just upstream of the new bridge, and I wasn’t the only one; a short while later, a bald eagle was after that same fish!”
The sight of a fish swimming upstream at the nearly completed project gave us a hint to the potential boon this will have to Puget Sound, which Hanson’s employees in the Seattle region call home. Meadowdale was the first full stream mouth restoration project under the railway along Puget Sound, and its success is a template for future strategic restoration projects along the corridor, ranging from Dupont, Washington, to the U.S.-Canada border. Hanson is involved in a number of these efforts, including a study commissioned by the Tulalip Tribes and supported by BNSF to conduct an inventory of coastal stream mouths and embayments along the railroad and prioritize them for replacement. Hanson has also begun design and coordination work on three projects initiated from this study.
“The more we’re involved with projects like Meadowdale, the more we see common project themes emerge,” Laura said. “These projects seek to address multiple issues in addition to fish passage, including flooding mitigation, safety, recreational benefits and access improvements. They all have some level of site accessibility to support the feasibility of construction. They are also supported by strong partnerships of stakeholders who really step up to make them happen.”
Hanson Associate Project Manager Tristan Rickett, P.E., can be reached at trickett@hanson-inc.com.