The Willamette River Water Treatment Plant project was a joint effort between the City of Wilsonville and the Tualatin Valley Water District. The project is headed by the design/build engineering firm Montgomery Watson with Miller Hull as the design architect, and Murase Associates as landscape architect.
Scope: Included in the project scope is a 15 mgd plant that will service the residents of Wilsonville, a public park/landscape, an interpretive display, an 800 foot concrete and stone “garden wall” (the west wall of many of the plant buildings) that conceals the plant from the public park and from the neighbors. It also forms a backdrop for interpretive displays and for sheltered picnic areas. Also included is a 6,000 s.f. administration building which will house a laboratory, a conference room and support offices.
Design: The “garden wall” runs north-south, bisecting the site into the secure water treatment plant on one side and a public park and ponds on the other. The wall is essentially a series of connected building elevations that express the public works functions beyond. The garden wall maintains a top of wall datum line that is constant. The wall stays level as the site drops to the river bank.
At the south end, the raw water pump station pulls river water up to begin the process. Each wall segment denotes a particular purification process such as ozone generation, acti-flo (sedimentation), filtration, clear water storage and finally high pressure pumps that distribute water to the community.
From the garden side, a path of interpretive panels and view window portals look into and explain the piping, pumps, filters and water of the operating functions of the facility. This path along the wall culminates in a river view lookout. A public meeting room attaches to this wall and sits in a pond. Two park shelters containing 30 – student long picnic tables also attach to the wall.
The public park/landscape includes a water feature that consists of a series of ponds that continue through the length of the site. Storm water from the park side will empty into the different ponds. These ponds will enhance the local wildlife corridor along the western edge by providing natural eddies and emergent plants. The plants in the landscape are indigenous to the area and the surface treatment is mainly comprised of meadows with gravel pathways.