Fish passage and flood control drive new culvert design

The City of Roslyn needed a solution to alleviate ongoing flooding issues. The previous undersized culverts were unable to handle flood flows, resulting in road damage, exposure of a potable water main, and residential flooding. Our team designed an innovative, custom pre-cast concrete box culvert to alleviate these issues. The new culvert protects public and private property during high-intensity storm events and significantly reduces maintenance costs associated with aging stormwater infrastructure.

While this was primarily a flood control project, habitat restoration drove much of the design. Crystal Creek is protected for Salmonid, which can include any species of salmon, trout or char. The new culvert allows fish and other aquatic species to pass through what had previously been a barrier. This increases habitat connectivity within the Crystal Creek watershed thus enhancing the surrounding natural environment and supporting the City’s goal to create a better community for its citizens.


American Council of Engineering Companies, Washington
American Council of Engineering Companies, Washington
Engineering Excellence Award