Johnson Creek Restoration and Design forTideman Johnson Park
City of Portland Bureau of Environmental Services

Vigil-Agrimis, Inc. (VAI) provided a full range of services to the City of Portland BES for the habitat enhancement and protection of an exposed sanitary sewer line in a segment of Johnson Creek. This work also included the restoration design for adjacent Tideman Johnson Park.

For the sewer line stabilization and habitat enhancement design, VAI developed four design alternatives that not only protected the exposed pipe but also enhanced approximately 1,800 feet of stream channel and ESA listed fish habitat. The final stream restoration design included: stream diversions, pipe encapsulation, channel roughness elements, three engineered log jams, large woody debris (LWD) elements, aggradation of the streambed with appropriate gravels, and bio-engineered bank stabilization. VAI also performed floodplain enhancements on the twelve acres in this area and adjacent to Tideman Johnson Park. Floodplain enhancements included grading to restore function to the abandoned floodplain and floodplain overflow channels.

Restoration design for Tideman Johnson Park redevelopment focused on providing directed access through the site, consisting largely of floodplain and associated wetlands. The design for the park included 2,000 feet of paved trails, a boardwalk, a wetland overlook, revegetation with native species, and a low profile exclusion fence to protect the sensitive riparian area. Pedestrian considerations such as connecting the internal trail to the Springwater Corridor Trail and providing ADA accessible trails were key objectives for the park design.

Following the completion of final restoration plans for the creek and park, VAI developed construction documents for the project that included: tree protection, grading and erosion control, channel restoration, site layout, and revegetation plans and details. VAI was also responsible for the Biological Assessment, Removal/Fill, permitting and a Letter of Map Revision (LOMR) for FEMA documenting alternations to the 100-year floodplain. This project was successfully completed in the summer of 2006.