IN 2011, JENIFER MCINTYRE, A RESEARCH SCIENTIST AT WASHINGTON STATE UNIVERSITY, DISCOVERED THAT SALMON EXPOSED TO WATER RUNOFF FROM THE 520 BRIDGE (WHICH RUNS ACROSS LAKE WASHINGTON) WERE DYING WITHIN HOURS DUE TO HEAVY POLLUTANTS DEPOSITED BY BRIDGE TRAFFIC. The results inspired architecture firm Weber Thompson and Mark Grey (representing development firms Stephen C. Grey & Associates and COU) to include stormwater treatment plans for two new buildings near another Seattle pollution source: The Aurora Bridge, linking Fremont to Queen Anne.
The two structures—the DATA 1 commercial building, completed last year, and the neighboring Watershed building, opening in late 2019—sit at the Aurora’s northern foot. In 2015, crews on the DATA 1 construction site realized that the bridge’s downspouts were carrying polluted water past the site, into Lake Union, and directly into the path of migrating salmon. Alarmed, Weber Thompson, Grey, and KPFF Consulting Engineers installed biofiltration retention planters on the east side of the DATA 1 site, which now treat up to 200,000 gallons of rainwater from the bridge each year.
The team also installed a biofiltration system at the Watershed building that will treat 320,000 to 400,000 gallons of runoff from the Aurora Bridge each year. Designed with gabion walls, 22-foot-wide bioretention planters, and hardy plants, the stormwater system will filter water multiple times before it collects in a dedicated drain that leads to Lake Union. Meanwhile, Watershed’s sloped, overhanging roof will channel cascading rainwater into a collection system that terminates in a sculptural catchment basin before flowing into a cistern in the building’s basement. From there the water will recirculate for use inside the building. It’s a happy win for both those with feet and those with fins.