The Swamp Creek watershed is located on the traditional lands of the Coast Salish, Stillaguamish, and Suquamish Peoples. The creek originates in the Paine Field and Casino Road area of South Everett, and the watershed drains water from Martha Lake, Lake Stickney, Scriber Lake, and portions of Lynnwood, Everett, Bothell, Kenmore, Brier, Mountlake Terrace, and unincorporated Snohomish County. In total, the creek flows 10.9 miles southward into King County where it empties into the Sammamish River, just upstream of Lake Washington.
Historically, this creek and watershed has been an important salmon bearing habitat with rich wetlands and diverse forests where indigenous peoples could gather and harvest food and materials. The headwaters were once dominated by extensive wetlands. There are still some large good-quality wetlands and salmonid spawning habitat, as well as one of the largest populations of freshwater mussels found in the Puget Sound Lowlands. However, despite there being some good quality habitat remaining, 52% of the roughly 52,000 acre Swamp Creek basin is covered with impervious surfaces (ie. concrete, pavement, rooftops, anything that water runs across and cannot reach the soil layers), 88% of the area is developed, only 8% is forested, and 4% consists of open water, wetland, or grassland. Of this wetland and stream habitat, the streambank stability is generally poor, but more-so in the middle and lower portions of the watershed- closer to the Sammamish River and Lake Washington. Increased urbanization has resulted in peak flows of greater intensity and duration, lower summer flows, increased flashiness, over-widening of the stream channel, bank erosion, and scour of the streambed (Kerwin, 20020). Increased flows from 1964-1990 were found to coincide with urbanization over the same period.
Volunteers in the Salmon Watcher Program had consistently seen Coho salmon in the creek, and occasionally kokanee and sockeye salmon. Chinook salmon have not been seen here. Most segments of the creek are rated low to medium-low for salmonid habitat quality, though a few segments rate medium-high. Due to the presence of salmonid populations here in the watershed and the significance of this habitat wildlife and water drainage overall, a lot of effort has been put into working to restore these habitats!
We started a project in a portion of Swamp Creek that is in the lower end of the watershed, not too far from where it empties into the Sammamish River. This site was previously a homeowner's residence, but now is being restored to improve wildlife habitat, control invasive species and noxious weeds, and is hopefully the site of a small future public park! We began work on a forested patch near the road where there is a row of Douglas Firs and some native shrubs that were shrouded by himalayan blackberry, English holly, and plenty of English ivy.
We minced up the blackberry canes that were blocking our easy access to the holly and ivy, and then started tearing into the ivy. For this site, we are starting with survival rings on the ivy trees. This means removing ivy from shoulder height down the trunk, and then all the ground ivy within 3 feet of the trunk. This will cut off the ivy high up the tree from its source of nutrients and water forcing it to die off, and reduce pressure on the trees. See below for a before and after shot of one of sever trees we did survival rings on!
Here's another before and after shot of the ivy ring work on these trees!
You may be wondering what we do with all the ivy we remove? Ivy has a frustrating characteristic where it can easily re-root and grow new vines if any part of the main vine containing a node with growth tissue is able to access the soil. We do our best to elevate removed ivy vines "high and dry" on compost piles, usually built upon a "raft" of sticks, and with cardboard on top if available. Luckily, this site had plenty of downed woody debris to make rafts with for us to float the ivy where it can dry out and decompose without spreading further.
This watershed is home to a large variety of wildlife including the salmonid species and freshwater mussels mentioned earlier, as well as deer populations, Great Blue Herons (there is a large rookery on the lower watershed!), Bald Eagles, many other local bird species, coyotes, and numerous other wildlife species. We look forward to returning to continue our work at this new restoration site to help increase the ecological health and functioning as a part of the greater Swamp Creek Watershed!
We will be back a few more times throughout the year to perform follow-up work on the ivy, as well as to treat some over invasive species present on site. Along with the blackberry and holly which will be treated, there is also yellow flag iris and knotweed that will need controlled in order to restore this habitat and prevent further spreading of these species throughout the watershed. This project is a partnership with the City of Kenmore and King County Noxious Weeds.
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Sources:
-King County Stream Report.
-Little Swamp Creek: The Record of a Suburban Stream. http://www.littleswampcreek.com/2015/02/the-size-of-swamp-creek-watershed-may.html