Tolt Water Treatment Facility

Owner: Seattle Public Utilities
Scope: $65 million, 126,500 SF

Inspired by the forested Tolt River watershed and geologic process that created the site, this facility reveals itself like stone formations unearthed by glacial erosion. Functional massings are organized as boulders protruding from the banks of a river channel. Water enters the facility at the east and flows in a linear progression to the west as it undergoes the first steps of purification. The rigor of plant operations is balanced with a respect for nature: light as a source of connection to the environment, sensitivity to regional weather patterns, and natural materials that reflect local resources. The heavy timber columns and bracing elements form the main structural support of the central gallery, suggesting natural vegetation along the edges of the stream and the system of purification that occurs in nature.