Project #6128/6129
Two parallel capital projects located between NW 143rd Avenue and NW 153rd Avenue along Willow Creek and Oak Hills Drive are being constructed in 2005-06.
Stream/wetland enhancement
The first phase of the project was completed in summer 2005 during the instream work season (July – September). The goal of the enhancement is to reduce flooding in the back yards of homes along Oak Hills Drive. Willow Creek was re-meandered or "looped out" away from the rear yards of homes that were experiencing flooding. Some portions of the old stream channel were preserved for habitat and water storage during high flows from rain storms.
The stream was redirected to provide to access to the relatively large wetland area and a berm was removed that had been constructed many years ago in the center of the wetland. After completion of the stream work, the area was mowed to remove invasive reed canary grass and Himalayan blackberry, and the area was seeded with native grass. During Spring 2006, the entire area will be revegetated with native plants and trees.
In partnership with BPA, excavated material was placed in the BPA right-of-way to provide additional habitat restoration.
Sewer upgrade
A sanitary sewer line is being upgraded in Spring 2006 to increase capacity. The sanitary sewer project is located in two areas - on the street along Oak Hills Drive and then along the rear of properties to an existing line at NW 153rd.
The portion of the project being constructed within the street follows Oak Hills Drive from 143rd to west of the BPA right-of-way. The existing 10-inch sanitary sewer is being supplemented with approximately 1,200 feet of new, parallel 15-inch sewer. This portion of the construction is being completed by traditional open trench style construction and is expected to take 3-4 weeks. Homes on the north side of Oak Hills Drive will then be reconnected to the new line while those on the south side will remain connected to the existing sewer.
The remaining portion of the sewer upgrade has been constructed within an existing 20-foot wide easement along the rear of the properties. A trenchless (no-dig) type technology was used to simultaneously burst and upsize the existing pipe underground in its present location. The pipebursting method reduces impacts to landscaping and trees.
UPDATE - Project Complete
The project is now complete and construction was accepted by the Clean Water Services Board of Directors on April 17, 2007 by Minute Order No. 07-36.
Contact information
Tom Lawler, Project Manager at (503) 681-4426 or lawlert@cleanwaterservices.org
Jeanna Cernazanu, Public Involvement Coordinator at (503) 681-3619 or cernazanuj@cleanwaterservices.org