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Lake Forest Park Streams Report 2012

Water Quality

LFP StreamKeepers conducted basic water quality testing twice during 2012, in January and July, at eleven locations on Lyon and McAleer Creeks. We found good levels of dissolved oxygen (DO) throughout, with slightly higher levels in the winter, typical of colder water. From our past testing, and from City of Mountlake Terrace testing, we know that McAleer Creek has a low level of DO when it leaves Lake Ballinger, its source, but recovers DO quickly as it flows through Shoreline and Lake Forest Park. Stream temperatures were also in normal ranges, between 60 and 64 degrees F. in July, and 40 – 42 degrees in January.

StreamKeepers conducted an inventory of stream insects and other macroinvertebrates in late September 2012, as part of an ongoing program to better understand the health of our streams by analyzing the numbers and kinds of animals that are able to live in the streambeds. Macroinvertebrates are near the base of the stream food chain, and support populations of fish, birds and, other larger animals. Samples were collected at two locations on each stream and analysed by a trained entomologist, following a procedure developed at the UW, the Benthic Index of Biologic Integrity (BIBI). On a scale of 10 – 50, the two sites on McAleer Creek both scored 24, considered in the Poor range. In 2010, both sites scored higher, with a rating of Fair.

On Lyon Creek, one location received a score of 22, a Poor rating; the other site scored 28, or Fair – the highest score in 6 years of BIBI testing for a Lyon Creek location. It is noteworthy that the resident immediately upstream from the site completed a stream bank stabilization project two years ago, resulting in less sedimentation into the stream at that location. Sedimentation, along with toxins in the stream, is a major cause of low populations of macroinvertebrates.

King County does monthly testing of several water quality parameters (fecal coliform, dissolved oxygen, pH (acidity), phosphorus, suspended solids, and temperature) on Lyon Creek, at one location near its outflow into Lake Washington. Results in 2012 were generally within normal ranges, although there were several spikes in fecal coliform during the year, especially after storm events. Poorly functioning septic systems and animal feces are common sources of fecal coliform in streams. It is present in our streams at varying concentrations year round. While not usually a threat to fish, it can cause illness in people who come in contact with stream water, and it is considered a “marker” for the more serious e. coli bacteria. Both Lyon and McAleer Creeks are included on the State’s impaired streams list due to high fecal coliform levels. King County’s testing on McAleer Creek was discontinued in 2008, but will begin again in 2013. More King County information about Lyon and McAleer Creeks is available from a page on the King County Website:


Salmon Returns

Each fall, salmon watchers visit locations along our streams to check for returning salmon. Sightings on Lyon Creek have been extremely rare for years, and none was observed this year. On McAleer Creek, however, as many as 16 mature salmon were spotted at several locations. Some were observed preparing redds, depressions in gravel beds for depositing eggs. From their bright red coloration, the salmon appeared to be sockeye, with the exception of one chinook salmon carcass. This is the largest number of salmon observed in the stream in several years – last year only one was spotted – but far from the hundreds of fish routinely observed in the creek as recently as 40 years ago.

Less than a week after the sightings, just before Thanksgiving, heavy rains over several days caused extreme water volumes and velocity, with roadway flooding on Bothell Way. Salmon have evolved a spawning process that protects fertilized eggs from the regular fall and winter storms that are typical of this region. However the amount of storm water diverted directly into streams in urban watersheds, like ours, is much greater than under pre-development conditions. Our watershed, for example includes Mountlake Terrace, as well as much of Lynnwood, and parts of Edmonds and Shoreline. We don’t know how prolonged storm events effect the survival of fertilized eggs, but we do know that high water volumes negatively impact the streambeds by washing away gravel beds needed for spawning, or burying them with silt introduced from bank erosion.

Salmon Raising and Releasing

Salmon Rearing BarrelSeveral ongoing salmon release programs were active during 2012. Students at three elementary schools – Brookside, Lake Forest Park, and Ridgecrest – hatched salmon eggs in school aquariums and released fingerlings into tributaries of McAleer Creek. Those projects were supported by the Lake Forest Park Stewardship Foundation and are part of the Salmon in the Schools Program. In addition, several individuals raised and released salmon at two locations on McAleer Creek and one on Lyon. All the salmon released were coho salmon, from fertilized eggs provided by the Issaquah State Hatchery.

Community Stream Education

Two workshops for streamside residents were held at Third Place Commons in the late spring. The sessions were arranged by the LFP Environmental Quality Commission and conducted by the Adopt-A-Stream Foundation of Snohomish County (AASF). They were attended by about 35 people, including some from outside LFP. Also in the spring, AASF conducted a Streamkeepers Academy, a 5-session program covering a variety of topics, attended by an average of 20 people. The King County Conservation District provided funding for both the workshops and Academy sessions.

In addition, the Stewardship Foundation’s annual meeting in November included a presentation on rain gardens, an important tool for preventing excessive storm water runoff into our streams.

Stream Restoration

Restoration activities on our streams last year were primarily aimed at removing invasive plants from riparian zones, and were led by the LFP Stewardship Foundation. Ivy Out workdays were held throughout the year, with extra support from enthusiastic volunteers with the Friends of the Cedar River Watershed. Similarly, City parks volunteers coordinated by the Foundation removed invasive plants from streams banks in our parks.

Stream Issues

Large volumes of storm water runoff from development. Storm water carries toxic substances from streets, homes, lawns, and other sources, and, in the volumes that we frequently experience, causes physical damage to stream banks and beds. Low impact development measures are important ways to reduce runoff from developed sites into streams. Installing rain gardens and replacing hard surfaces with permeable surfaces are steps residents can take to reduce storm water runoff from their properties.

Stream barriers and bank armoring. Both of our streams have numerous dams that present barriers to the movement of small fish and other aquatic animals, limiting the habitat they need to find food and protection. Some barriers are large enough to stop the upstream migration of mature salmon. The most serious of these is on Lyon Creek, at Ballinger Way, where a private culvert collapse in 1996 created a total barrier to passage. Several undersized culverts carrying streams under public roads have been upgraded in recent years, but there are still many that need to be enlarged – witness the recent failures of two stream culverts causing temporary road closures.

Extensive “armoring” of stream banks along many portions of the streams eliminates water filtration, habitat, and other wetland benefits. Heightened stream-flow velocity contributes to major downstream flooding and habitat damage.

Invasive plants. Knotweed, English ivy and blackberries are very common along many stretches of our streams, growing rapidly and crowding out native plants. Knotweed, especially, thrives in streamside environments. These plants are not native to the area and do not provide suitable habitat for the insects, birds, and other animals that have evolved in our region.

Lyon Creek By-Pass. This year Lake Forest Park received a $3 million dollar FEMA grant for the construction of a by-pass pipe to divert some water from Lyon Creek to a point near Lake Washington during high flow storms. StreamKeepers believes the City should conduct the most complete possible environmental impact study before finalizing the design for this project.

McAleer and Lyon Creeks have been greatly impacted by commercial and residential development over the last 30 years. Most of the watershed they comprise is within 25 miles of downtown Seattle and includes portions of several heavily built municipal jurisdictions. Though seriously impaired, LFP’s two streams show a remarkable resiliency. They still support populations of aquatic insects and other small animals that, although reduced, still contribute to stream habitat for fish and other larger animals. At least one stream, McAleer, still attracts returning salmon. And despite LFP’s urban setting, there are still many places on our two streams that seem relatively isolated and afford a true experience of a natural environment. Our two streams are wonderful resources, well worth our continued investment of time and resources.