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The Adopt-A-Stream Foundation |
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MODEL PROJECT - The Stream North Creek is salmon-bearing coastal lowland stream whose headwaters lie near the Everett Shopping Mall in Everett, Washington. The stream is a tributary of the Sammamish River. On its journey south, the waters of North Creek flow by the adjacent lands of the Northwest Stream Center, Adopt-A-Stream's headquarters, in McCollum Park. Historically, the stream provided a home to four salmonid species, including Chinook salmon, coho, sockeye and searun cutthroat. Sculpin, brook lamprey and a host of macroinvertebrates also inhabit North Creek's waters. Along much of its length, the stream has been heavily impacted first by logging in the 19th and early 20th centuries, then agriculture and now by urban and suburban development. The construction of roads, houses and buildings has degraded salmon habitat, riparian areas and subsequently water quality. In an effort to protect and restore this stream, Adopt-A-Stream has committed resources and energy to address some of these pressures. Much of North Creek was straightened or channelized, and woody material removed in the early part of the century to facilitate log transport by the timber industry. The result of such practices was increased stream flows, streambed erosion, deeply cut banks and the destruction of valuable salmon spawning and rearing habitat. To address these problems in McCollum Park, the Habitat Restoration Crew surveyed a 750-foot reach of the stream starting at 128th Street SE. These data were analyzed and an action plan for restoration was developed. To reduce high water velocities at 128th Street, the crew constructed a 300-foot high flow channel paralleling the existing channel. An additional culvert, equal in size was installed under a maintenance road next to an existing undersized culvert. This more than doubled the flow capacity. In many places the stream had eroded to hardpan. To aid in sediment control resulting from the heavy streambed erosion, 16 different grade control structures were installed, along with one large deflector and seven Large Woody Debris (LWD) structures in the old and new channels. Bank logs, log jams and root wads, securely anchored into the stream bank with cables and earth anchors, help maintain the gravel bed and provide spawning and rearing habitat for juvenile and adult fish. An additional 300 feet of channel was widened by an average of 10 feet to better accommodate seasonal high flows and reduce the associated erosion these flows cause. More than 25 large rocks were placed strategically along the work area to create scour pools, partial weirs and to reduce flow energy. The restoration crew also amended the streambed with over 55 yards of smaller mixed alluvial materials. Exposed soils were stabilized with geotextiles and native plantings along the entire work area. Root wads and log structures were added to the stream utilizing logging "high line" techniques to minimize damage to riparian habitats that would ordinarily result with the use of heavy equipment. The Wetland The Northwest Stream Center site comprises 20 acres of land leased from Snohomish County. Sixteen acres consist of forested and shrub/scrub wetlands adjacent to North Creek. In the 1970's four acres of this fragile ecosystem were filled to accommodate a gravel parking lot. Beginning in 1994, the Habitat Restoration Crew initiated a major recovery project to restore 1.35 acres to its original state--a palustrine emergent wetland. The Crew sculpted an open water wetland into a natural shape and in the process excavated 4000 cubic yards of fill (400 dump truck loads). This fill was subsequently "recycled" in the McCollum Park and Ride, which rests on a former landfill. The crew was able to salvage two cedar "snags" from nearby construction sites, along with 15 logs and stumps, which provide wildlife habitat. A beaver dam and lodge facsimile were constructed as well. To complete the restoration project, the site was revegetated with native wetland plants, including sedges, rushes, grasses, willows, red osier dogwood and various aquatic plants. Habitat
Restoration Projects 2003-2004 |
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