Program on the Environment

The Duwamish River Valley – Seattle’s most vulnerable area to sea level rise – lies at the intersection of melting glaciers, warming oceans, and a Pacific Northwest watershed shifting to rain-dominated hydrology, placing critical buried electrical infrastructure at compounding, poorly understood risk. This study investigates how sea level rise and groundwater alteration threaten Seattle City Light’s buried cables, vaults, and substations in the Duwamish Valley, and examines how Seattle City Light employees perceive and institutionally prioritize these hazards. Through a capstone partnership with Seattle City Light (SCL), I conducted qualitative interviews with eight employees and two external experts, coded and analyzed every transcript in Atlas.ti, and used ArcGIS to overlay sea level rise and USGS groundwater projections onto SCL’s buried infrastructure across the valley. Findings show that subsurface conditions expose buried infrastructure to saltwater corrosion, oxygen-depleted enclosed environments, and lateral movement of Superfund-contaminated fill soil – chronic hazards that compound silently until the systems fail. Employees prioritize immediate, visible hazards over slower underground threats because SCL’s climate vulnerability framework predates recent groundwater science identifying these risks. The gap between what science now shows and what the institution currently plans for is consequential, but still closable. As coastal cities worldwide face the same convergence of sea level rise and aging buried infrastructure, the Duwamish Valley offers an urgent, concrete case for what utility climate resilience planning must become.