Kenmore Shoreline Inventory and Characterization

Preliminary Summary of Findings

Background and Purpose

Cities and counties updating their Shoreline Master Program (SMP) are required to prepare an inventory and characterization of the shoreline resources in their jurisdiction. The City of Kenmore has received a grant from the Washington State Department of Ecology to complete the SMP process. As part of the City’s SMP update, a preliminary draft inventory and characterization report and map folio has been prepared and will be finalized in June of 2008, following review by Ecology and the Technical Advisory Committee (TAC).

The purpose of the study is to create a baseline inventory of conditions in the shoreline jurisdiction of the City of Kenmore using existing data sources. The inventory and characterization provides and understanding of the physical, biological, and cultural resources in the shoreline, to be used as a basis for updating the City’s SMP to comply with the Shoreline Management Act (SMA), Revised Code of Washington (RCW) 90.58 and its implementing guidelines, Washington Administrative Code (WAC) 173-26. The waterbodies within the City shoreline planning area include the Lake Washington, the Sammamish River, and the Main stem of Swamp Creek, and these have been broken to 10 “reaches” as outlined in Table 1 below.

Table 1. City of Kenmore Shoreline Planning Area

Wetlands Reach (Excluding Open Reach Area Reach Name Length (Acres) Water) (Miles) (Acres/percent of shoreline area) Lake Washington 01 18.2 0.8 0.4 2.1% Lake Washington 02 36.3 1.4 9.7 26.8% Lake Washington 03 38.7 1.0 0.1 0.3% Lake Washington 04 7.7 0.3 0.5 6.1% Sammamish River 01 37.9 0.4 7.5 19.8% Sammamish River 02 34.8 0.4 14.1 40.5% Sammamish River 03 72.2 1.1 13.7 19.0% Swamp Creek 01 29.2 0.5 11.9 40.7% Swamp Creek 02 9.7 0.2 0.0 0.0% Swamp Creek 03 134.9 0.9 111.3 82.5% Swamp Creek 04 55.6 0.9 14.1 25.3% TOTAL 475.2 7.9 183.3 38.5%

The shoreline characterization identifies existing conditions, identifies current uses and public access, evaluates functions and values of resources in the shoreline jurisdiction, and explores Planning Commission Meeting, February 20, 2008 opportunities for conservation and restoration of ecological functions. The findings are intended to provide a framework for updates to the City’s shoreline management goals, policies, and development regulations. Key findings of the inventory and characterization are summarized below.

Physical & Biological

The City of Kenmore is located within the Water Resource Inventory Area (WRIA) 8, Cedar – Sammamish Watershed, which encompasses 692 square miles and collects water from two major rivers (Cedar and Sammamish Rivers) before flowing into Puget Sound via the Hiram Chittenden Locks. The designated shoreline areas for the City of Kenmore include 3.8 miles along the northern end of Lake Washington, the western portion of the Sammamish River, and the mainstem of Swamp Creek.

The terrestrial and aquatic ecosystem at the northern end of Lake Washington is closely associated with the Sammamish River. The lake has a long history including a 10-foot drop in lake level that exposed an entirely new shoreline of Kenmore, as well as changes to both the inflow and outflow of the lake. Lake Washington is primarily fed by surface water inputs and therefore tends to be at high risk for water quality degradation. Much of the pollution that reaches the lake comes from sources outside if the shoreline, especially runoff roadway and parking areas.

The Sammamish River drains a watershed of about 240 square miles and has a total length of 13.8 river miles, of which the lower 1.82 miles are in Kenmore. The wetlands and floodplains along the river in Kenmore are all areas that were at one time part of Lake Washington. The weir at Marymoor Park controls the rate of water flowing from Lake Sammamish into the river.

Swamp Creek drains an area of approximately 23.5 square miles. Originating in the southern extents of the city of Everett, the mainstem of the creek flows approximately 14 miles before emptying into the Sammamish River approximately 0.7 miles upstream from where the river empties into the northern end of Lake Washington. The lower 2.53 miles of Swamp Creek are within Kenmore, and are abutted by extensive wetlands (Table 1).

Habitat and Species

The City’s shorelines are used by a variety of aquatic and terrestrial species. Of special interest are areas that provide habitat for federally listed species and species of local importance, including bull trout (threatened) and Chinook salmon (threatened), coho salmon, sockeye, kokanee, steelhead, coastal cutthroat, bald eagle, pileated woodpecker, and great blue heron. The entire shore of Lake Washington is designated critical habitat for bull trout and Chinook salmon. Approximately 48 percent of the shoreline has bulkheads or riprap, 4 percent is beach, and 48 percent is natural shoreline.

Land Use and Public Access

The major land uses along the Kenmore shoreline are single-family homes, parks, and commercial development. Single-family residential zoning occupies more than 50 percent of the land area within the shoreline. Multi-family development is becoming more common. Commercial 2

Planning Commission Meeting, February 20, 2008 developments (including office, retail, and industrial) occupy a significant portion of the city’s land area and are located primarily in the downtown area, along the major transportation corridor of Bothell Way. Industrial and manufacturing land areas are centralized along the northern Lake Washington and lower Sammamish River shorelines, including a variety of businesses.

Conclusions

The shoreline in Kenmore is characteristic of urbanizing shoreline elsewhere in the region. Public access to the shoreline, recreational opportunities, and water-oriented uses such as boating and fishing abound in the Kenmore. In this regard, goals of the SMA related to public use and enjoyment of the State’s shorelines are generally being met in the city. In some locations, the natural structure and functions occurring at the shoreline have been altered through development of shoreline armoring and removal of vegetation. On the other hand, St. Edward State Park and other parks provide natural shoreline conditions where processes remain unaltered.

Altered shorelines have lower value as fish and wildlife habitat, and often adjacent uses contribute pollutants to the adjacent waterbody such as through accidental spills, application of pesticides and fertilizers, and runoff from parking areas and roads. Additionally, development on a watershed scale has affected the shoreline by increasing impervious area in uplands, resulting in increased peak flow velocities and volumes, impaired water quality, and erosion in streams.

Restoration Opportunities

As part of the inventory opportunities for restoration of shoreline ecological functions are being identified. These will be refined as part of the SMP update process and compiled in a later report, the Shoreline Restoration Plan.

References available related to SMP updates:

Department of Ecology Shoreline Inventory Page : http://www.ecy.wa.gov/programs/sea/SMA/st_guide/SMP/inven_analysis/index.html Department of Ecology Shoreline Management Home Page: http://www.ecy.wa.gov/programs/sea/SMA/index.html King County Shoreline Management Home Page: http://www.metrokc.gov/shorelines/default.aspx

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