Seattle Waterfront Stormwater Revamp.pdf

The all-new Seattle Waterfront development features a seismically stable seawall and a green stormwater management system to maintain runoff along the entire development. The systems had to meet regulatory requirements for basic treatment with GULD approval by the Department of Ecology and the City of Seattle. The City of Seattle sought the longevity of a solution that can only be found in precast concrete, using Oldcastle Infrastructure's PerkFilter catch basins and vault units. The PerkFilter product had been used in jobs for the City of Seattle previously, providing familiarity and trust with the product.

The project faced challenges in coordinating multiple stakeholders and navigating complex infrastructure below street level. The existing Alaskan Way Viaduct required full demolition to build the new Alaskan Way within the same footprint, resulting in a complex schedule for installation. The Oldcastle team met the HS-25 traffic load rating for all structures, redesigned pedestrian and vehicular traffic to include PerkFilter systems, ensured approved inlet vane grating on all catch basins, and provided stamped structural design calculations and drawings for every unit.

The PerkFilter treatment system offered reliability, security, and timeliness. Precast concrete provided a long-term durability and service life, unmatched by steel in a marine climate. The PerkFilter system stood up to vehicle traffic better due to its stronger top lid design, and product delivery was done in phases to ensure timely installation. The concrete PerkFilter treatment system was the perfect fit for this high-profile project, providing stronger stormwater management now and into the future.