The City of Shoreline (City) plans to remove an existing dam impounding Boeing Creek at Hidden Lake on the western edge of Shoreview Park, replace existing undersized culverts that convey the creek’s flow beneath NW Innis Arden Way downstream of the damsite, restore a free-flowing stream channel and floodplain, plant native riparian vegetation in the restored floodplain and on the rebuilt roadside embankments, and improve trails for park users to access the restored creek area. Herrera is leading a multidisciplinary consultant team in assisting the City with all aspects of project design and permitting. This project team encompasses expertise in watershed hydrology, hydraulics, stream restoration engineering, geomorphology, geotechnical engineering, structural engineering, surveying, wetlands and stream ecology, fisheries biology, environmental permitting, stakeholder involvement, and private property easement negotiations.
Two 48-inch-diameter culverts beneath NW Innis Arden Way will be replaced with a 25-foot diameter arch culvert that assures fish passage, sediment transport, and woody debris passage during floods. The design for culvert replacements addresses several utilities that are present within the NW Innis Arden Way embankment, including a sanitary sewer trunk line that must remain in service during construction. The completed project will restore natural ecological functions in this reach of Boeing Creek while also restoring sediment transport to the mouth of Boeing Creek at the Puget Sound shoreline, where important estuarine nearshore habitat at the creek delta has been reduced for decades due to sediment trapping in the manmade lake.