Tied by water

Seattle, Tacoma, and three utilities in the southern part of King County already are investing $250 million in a new regional water transfer arrangement: the Tacoma-Seattle intertie (TSI), or second supply project. The project involves adding additional storage and improving fish passage facilities at the Howard A. Hanson Dam and Eagle Reservoir, building water treatment facilities, and constructing a 33 mi, 60 in. diameter pipeline and an 8 mi, 42 in. diameter pipeline. This transfer between Tacoma and Seattle sets the stage for further regionalization of central Puget Sound in what is referred to as the Everett-Seattle intertie (ESI). Although legal and political impediments have hindered a full evaluation of the proposed ESI project, an agreement could represent the most promising alternative source of water for the growing metropolitan region.