Introduction: the Kroger Park Bioswale (formerly known as Cannery Park)

National and regional studies have found that larger concentrations of pollutants enter streams in urban areas than in undeveloped watersheds. A major reason for this is the high percentage of land covered with impervious surfaces, such as street pavement and roofs. Impervious surfaces are intended to prevent flooding by rapidly draining stormwater to streams via piped or ditched stormwater systems. As water moves across building tops or parking lots, a variety of pollutants—automobile oil, brake liner metals, fertilizer, etc.—are picked up and discharged into the nearest stream.

To demonstrate a stormwater "best management practice (BMP)" technique that can reduce water pollution, the City of Salem constructed a bioswale in Kroger Park during the summer and fall of 2001. Kroger Park, a seven acre neighborhood park located in South Salem, borders both Pringle Creek and a facility called Shurgard Storage. Shurgard has multiple, enclosed storage units and spaces for such items as RV's, vehicles, boats, etc. The Shurgard site, typical of other commercial and industrial areas, is almost completely covered by roof tops and an asphalt parking lot. And like most other areas with large amounts of impervious surfaces, the stormwater from Shurgard discharges directly into the nearest stream (Pringle Creek).

The Kroger Park Bioswale Demonstration Project was designed and built to treat the stormwater runoff from Shurgard Storage's 4.4 acre property before the water runs into Pringle Creek. The bioswale, which is a shallow "stream" that receives the Shurgard stormwater runoff, uses natural filtration to remove contaminants in the water before it enters Pringle Creek. The bioswale began operating in the fall of 2002.

The Kroger Park Bioswale Demonstration Project was jointly undertaken by Salem Public Works, Community Services, and Community Development Departments; Shurgard Storage, Inc.; the Pringle Creek Watershed Council; Marion County Master Gardeners; and the Oregon Watershed Enhancement Board (OWEB). This project was partially funded by an OWEB grant received in 1998. OWEB provides financial support for projects that improve watershed conditions throughout Oregon. The 25 percent local match required by OWEB grants was provided by the City of Salem and the other project partners listed above.

Bank Restoration Project

During construction of the bioswale, a streambank restoration project was implemented along parts of Pringle Creek. As Pringle Creek flows through Kroger Park, the area nearest the bioswale has suffered from bank erosion, an incised channel, and a lack of an adequate vegetative canopy above the stream. To offset these conditions, the channel was regraded, erosion control matting was installed, and vegetation was planted to help stabilize soils and provide stream shading.

Bank restoration projects like these can help improve the biological function of local streams. By increasing the canopy cover over streams, shading of the water will help minimize the problem of high water temperatures for fish. Bank stabilization helps control erosion, thus decreasing the amount of sediments that may move into the stream. Sediments can choke spawning beds and make finding food difficult for young fish. The result will be cleaner, cooler water in Pringle Creek.

Project Location

The bioswale project is located in Kroger Park, 200 Arlene Avenue SE. Click on the map icon on the left to see an enlarged copy of the map.