by Jason King
The initial grading got started for the NAYA Bioswale, a linear rain garden in Northeast Portland on the grounds of the Native American Youth & Family Center. The site is also where Verde offices are located, along with their small nursery area where they store and propagate plant materials for work throughout the community. The nursery is semi-pervious, so the swale will capture any additional runoff that
The existing condition shows the narrow strip of land that has been designated for the bioswale.
The first phase involved grading the site to accommodate the runoff and direct it into the swale at key points. Three areas were provided for inlets, spaced apart and allowing water to flow around existing features like the large existing Sweetgum tree. This created three distinct ‘cells’ which allow for infiltration, with weirs placed in between to maximize water capture. Areas to the south are graded to provide an escape route if runoff is greater than the area can handle in a large storm. The combination of berming and depressions also allowed for balanced cut and fill, with no removal of soil necessary.
Yesterday and today, students participated in planting of the swale area, using a range of plants adapted for use in stormwater facilities, and grown on-site by Verde nursery supervisors Nestor Campos. The planting included a range of rushes and sedges, Sword Fern, Oregon Grape, and other native plantings selected for in-water or upland habitat. The image below shows the planting plan and the initial installation of plantings.
The final stages include installation of gravel mulch, final plantings, and fine tuning of outfall areas, making this a continual learning experience for the students of NAYA and the landscape contractors at Verde. Look for some final photos of this in the coming week as it gets finished.
