Outreach Event: Cascades Dam Tour

Seattle Public Utilities is hosting an outreach event and dam facility tour on October 22, 2026 from 10 a.m. to 1 p.m. at the Cascade Dam facility at Lake Youngs in unincorporated King County, Washington to brief potential consultants on two upcoming design contracting opportunities: Cascades Dam and Perimeter Dike Design, and Lake Youngs Perimeter Drain Lining.

The three-hour tour will include a walk of portions of the Cascade Dam facility and Lake Youngs Reservoir Perimeter Dike, a historical and functional overview of the site, and discussion of the two upcoming consultant solicitations. The Lake Youngs Perimeter Drain Lining scope involves approximately 26,000 linear feet of drainage infrastructure comprising vitrified clay pipe and concrete drain lines ranging from 8 inches to 24 inches in diameter (predominantly 18-inch pipe), 37 numbered manholes, and four outfalls. A previously rehabilitated Cured-in-Place Pipe section is identified within the system. The drainage network spans unincorporated King County with topographic and infrastructure mapping based on State Plane coordinates (NAD83-91, Washington North Zone).

An attached Options Analysis Study Report and a Lake Youngs Perimeter Drains technical map with sections highlighted provide supporting documentation for the project scope and alternatives analysis. No formal proposal deadline, contract value, contract term, or procurement timeline for the two design contracts is stated in this outreach notice; the event functions as a pre-bid informational session to inform potential bidders and solicit consultant participation prior to formal RFP issuance.