For City of Bellevue Shorelines: Lake Washington, Lake Sammamish, Phantom Lake, Larson Lake, Kelsey Creek and Mercer Slough
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CITY OF BELLEVUE GRANT NO. G0800105 C U M U L A T I V E I M P A C T S A NALYSIS for City of Bellevue Shorelines: Lake Washington, Lake Sammamish, Phantom Lake, Larson Lake, Kelsey Creek and Mercer Slough Prepared for: City of Bellevue Development Services Department 450 110th Ave. NE Bellevue, WA 98009 Prepared by: 750 6th Street South Kirkland, WA 98033 June 2015 The Watershed Company Reference Number: 070613 Cite this document as: The Watershed Company. June 2015. Cumulative Impacts Analysis for the City of Bellevue Shorelines: Lake Washington, Lake Sammamish, Phantom Lake, Larson Lake, Kelsey Creek and Mercer Slough. Prepared for the City of Bellevue Development Services Department. Cumulative Impacts Analysis City of Bellevue The Watershed Company August 2015 T A B L E O F C ONTENTS Page # Grant No. G0800105 ........................................................................ 1 Cumulative Impacts Analysis ......................................................... 1 Cite this document as: .................................................................... 1 1 Introduction ............................................................................... 1 1.1 Preamble ................................................................................................. 1 1.2 Document Overview ............................................................................... 5 2 Methodology .............................................................................. 5 3 Existing Conditions ................................................................... 7 3.1 Existing Conditions Summaries by Waterbody ................................... 7 3.1.1 Lake Washington .............................................................................................. 8 3.1.2 Kelsey Creek/Mercer Slough ......................................................................... 11 3.1.3 Lake Sammamish ........................................................................................... 14 3.1.4 Phantom Lake ................................................................................................. 15 3.2 Existing Setbacks Analysis ................................................................. 17 3.3 Existing Vegetation Analysis .............................................................. 18 4 Anticipated Development ....................................................... 20 4.1 Shoreline Land Use Analysis .............................................................. 20 4.2 Permit History Analysis ....................................................................... 21 4.3 Summary of Anticipated Development ............................................... 22 5 Effect of Established Regulations and Programs ................. 22 5.1 City Regulations and Programs .......................................................... 22 5.2 King County Programs ........................................................................ 24 5.3 State Regulations ................................................................................. 24 5.4 Federal Regulations ............................................................................. 25 5.5 Shoreline Restoration Plan.................................................................. 27 6 Application of the SMP Provisions ........................................ 30 6.1 General Requirements Applicable to all Shoreline Development and Uses (LUC 25.25E.060) ........................................................................................ 30 6.2 Shoreline Uses (LUC 25.25E.070)........................................................ 31 6.2.1 Aquaculture (LUC 25.25E.070.B) .................................................................. 32 6.2.2 Recreation (LUC 20.25E.070.C) ..................................................................... 32 6.2.3 Residential (LUC 25.25E.065) ........................................................................ 33 6.2.4 Transportation (LUC 20.25E.070.D) .............................................................. 35 6.2.5 Utilities (20.25E.070.E) ................................................................................... 36 6.3 Shoreline Modifications (LUC 25.25E.080) ......................................... 37 6.3.1 Breakwaters, Jetties and Groins (LUC 25.23E.080.B) ................................ 37 Cumulative Impacts Analysis City of Bellevue 6.3.2 Clearing, Grading and Fill in the Shoreline (LUC 20.25E.080.C) ............... 38 6.3.3 Dredging and Dredge Material Disposal (LUC 20.25E.080.D) .................... 38 6.3.4 Non-Residential Moorage Facilities, Boat Ramps and Launches (LUC 20.25E.080.E) .............................................................................................................. 39 6.3.5 Shoreline Stabilization (LUC 20.25E.080.F) ................................................. 40 6.4 Shoreline Environment Designations ................................................. 41 6.4.1 Shoreline Residential Environment Designation ........................................ 47 Upland Development/Redevelopment ...............................................................................47 Overwater Structures ........................................................................................................52 Shoreline Stabilization .......................................................................................................54 6.4.2 Shoreline Residential Canal Environment Designation ............................. 55 6.4.3 Urban Conservancy & Urban Conservancy-Open Space Environment Designation ................................................................................................................ 56 Bellefield Office Complex ..................................................................................................57 6.4.4 Recreational Boating Environment Designation ........................................ 57 7 Summary of Net Effect on Ecological Function .................... 57 8 References ............................................................................... 59 9 Acronyms and Abbreviations ................................................. 60 A PPENDICES Appendix A Summary Tables of SMP Regulations that Protect Ecological Functions Appendix B Key Information Sources on Shoreline Functions and Effects of Shoreline Development in the City of Bellevue Appendix C Additional Information Provided by the Planning Commission and Bellevue Citizens Appendix C Shoreline Analysis Methodology L I S T O F F IGURES Figure 6-1. Upland environment designations generally ordered from higher ecological function/less intensive development to lower ecological function/more intensive development. .................................................... 42 Figure 6-2. Conceptual model of the continuum of lakeshore land cover values....... 49 L I S T O F T ABLES Table 3-1. Summary of ecological functions, as described in the Shoreline Analysis Report. ..................................................................................................... 8 The Watershed Company August 2015 Table 3-2. Lake Washington summary data. ............................................................. 9 Table 3-3. Lake Washington summary data by reach category. .............................. 10 Table 3-4. Lake Washington ecological function summary. ..................................... 11 Table 3-5. Kelsey Creek/Mercer Slough summary data. ......................................... 12 Table 3-6. Kelsey Creek / Mercer Slough summary data by reach. ......................... 13 Table 3-7. Kelsey Creek/Mercer Slough ecological function summary. ................... 14 Table 3-8. Lake Sammamish summary data. .......................................................... 14 Table 3-9. Lake Sammamish summary data by reach. ............................................ 15 Table 3-10. Lake Sammamish ecological function summary. .................................... 15 Table 3-11. Phantom Lake summary data. ................................................................ 16 Table 3-12. Phantom Lake summary data by reach. ................................................. 17 Table 3-13. Phantom Lake ecological function summary. ......................................... 17 Table 3-14. Existing setbacks by environment designation and waterbody. .............. 18 Table 3-15. Existing shrub and tree coverage in shoreline area by environment designation and waterbody. ................................................................... 19 Table 4-1. Shoreline permit history 2003 to 2013. ................................................... 21 Table 6-1. Summary of potential impacts from aquaculture. .................................... 32 Table 6-2. Summary of potential impacts from recreational development. ............... 33 Table 6-3. Summary of potential impacts from residential development and accessory uses. ..................................................................................... 34 Table 6-4. Summary of potential impacts from transportation facilities. ................... 36 Table 6-5. Summary of potential impacts from utilities. ........................................... 37 Table 6-6. Summary of potential impacts from breakwaters, jetties and groins. ...... 38 Table 6-7. Summary of potential impacts from clearing, grading and fill. ................. 38 Table 6-8. Summary of potential impacts from dredging and dredge disposal. ........ 39 Table 6-9. Summary of potential impacts from non-residential moorage