FINAL DRAFT SHORELINE INVENTORY, ANALYSIS, AND CHARACTERIZATION REPORT GRANT COUNTY SMP UPDATE Source: https://fortress.wa.gov/ecy/coastalatlas/UICoastalAtlas/Tools/ShorePhotos.aspx Prepared for Grant County, Coulee City, City of Electric City, City of Grand Coulee, City of Soap Lake, Town of Krupp, and Town of Wilson Creek Prepared by Prepared with assistance from Anchor QEA, LLC Oneza & Associates 8033 West Grandridge Boulevard, Suite A Kennewick, Washington 99336 This report was funded through a grant from Washington State Department of Ecology June 2013 TABLE OF CONTENTS 1 INTRODUCTION ................................................................................................................ 1 1.1 Background and Purpose .................................................................................................1 1.2 Regulatory Overview .......................................................................................................1 1.3 Report Organization.........................................................................................................2 2 GRANT COUNTY OVERVIEW .......................................................................................... 4 2.1 Land Use/Land Cover and Ownership ............................................................................4 2.2 Geology .............................................................................................................................7 2.3 Climate ..............................................................................................................................8 2.4 Water Resources ...............................................................................................................8 2.4.1 Groundwater ...............................................................................................................9 2.5 Floodplains and Floodways ............................................................................................11 2.6 Channel Migration Zones ..............................................................................................12 2.7 Geologic Hazards ............................................................................................................12 3 SHORELINE JURISDICTION ANALYSIS ......................................................................... 15 3.1 SMP Jurisdiction Determination Methodology ............................................................17 3.2 Shoreline Jurisdiction Analysis .....................................................................................19 3.3 GIS Data Limitations ......................................................................................................20 3.4 Determining Stream Shoreline Master Program Jurisdiction......................................20 3.4.1 Rivers and Streams ...................................................................................................22 3.4.2 Lakes ..........................................................................................................................22 4 SHORELINE INVENTORY, ANALYSIS, AND CHARACTERIZATION ......................... 26 4.1 Ecosystem-wide Processes and Structure .....................................................................26 4.1.1 Hydrology .................................................................................................................26 4.1.1.1 Lake and Reservoir Hydrology ...................................................................... 26 4.1.1.2 Stream Hydrology ........................................................................................... 27 4.1.2 Sediment ...................................................................................................................27 4.1.3 Water Quality ...........................................................................................................28 4.1.4 Habitat .......................................................................................................................28 4.1.4.1 Fish Habitat ..................................................................................................... 29 4.1.4.2 Shoreline (Riparian Habitat) .......................................................................... 30 Final Draft Shoreline Inventory, Analysis, and Characterization Report June 2013 Grant County Shoreline Master Program Update i 110827-01.01 Table of Contents 4.2 Process Alterations .........................................................................................................30 4.2.1 Columbia Basin Project Storage ...............................................................................30 4.2.2 Columbia Basin Project Diversion/Conveyance .....................................................31 4.2.3 Impervious Surface ...................................................................................................31 4.2.4 Vegetation Alterations .............................................................................................32 4.2.5 Water Quality Impacts .............................................................................................33 4.2.6 Structural Effects on Habitat ...................................................................................34 4.2.7 Shoreline Hardening/Stabilization ..........................................................................34 4.2.8 Channelization..........................................................................................................35 4.2.9 Other Alterations .....................................................................................................36 4.2.10 General Ecological Processes and Major Alterations Summary ............................36 4.3 Grant County Shoreline Ecosystem Characterizations ................................................38 4.4 Columbia River...............................................................................................................38 4.4.1 Existing Conditions ..................................................................................................38 4.5 Other Streams .................................................................................................................42 4.5.1 Crab Creek ................................................................................................................42 4.5.2 Rocky Ford Creek .....................................................................................................43 4.5.3 Lind Coulee ...............................................................................................................43 4.5.4 Ecosystem Processes and Alterations for Streams ..................................................44 4.6 Lakes and Reservoirs ......................................................................................................45 4.6.1 Crescent Bay and Lake Roosevelt ............................................................................45 4.6.2 Banks Lake ................................................................................................................46 4.6.3 Coffee and Long Lakes .............................................................................................46 4.6.4 Sun Lakes ..................................................................................................................46 4.6.5 Soap Lake ..................................................................................................................47 4.6.6 Reservoirs along Main Canal ...................................................................................47 4.6.7 Small Lakes South of Wilson Creek ........................................................................47 4.6.8 Ephrata Lake and Rocky Ford Lake .........................................................................47 4.6.9 Moses Lake ................................................................................................................48 4.6.10 Quincy Basin Lakes ..................................................................................................48 4.6.11 Potholes Coulee and Frenchman Coulee Lakes ......................................................48 4.6.12 Potholes Reservoir ....................................................................................................48 4.6.13 Drumheller Channel Lakes ......................................................................................49 Final Draft Shoreline Inventory, Analysis, and Characterization Report June 2013 Grant County Shoreline Master Program Update ii 110827-01.01 Table of Contents 4.6.14 Lakes North of Lower Crab Creek ...........................................................................49 4.6.15 Lower Grant County Lakes ......................................................................................49 4.6.16 Lake Ecosystem Processes and Alterations .............................................................49 4.6.17 Artificial Waterbodies ..............................................................................................50 4.7 Reach Breaks and Grouping of Waterbodies ................................................................52 4.8 Reach Characterizations ................................................................................................56 5 CRITICAL AREAS AND OTHER APPLICABLE REGULATIONS ................................... 58 6 PUBLIC ACCESS ...............................................................................................................