COLUSA BASIN WATERSHED ASSESSMENT. Final. Prepared by: H. T. Harvey & Associates. In Collaboration With:

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COLUSA BASIN WATERSHED ASSESSMENT Prepared by: In Collaboration With: G. Mathias Kondolf Geomorph Blankinship & Associates Prepared for: Colusa County Resource Conservation District 100 Sunrise Boulevard, Suite B Colusa, California 95932 Attn: Jennifer Masters Colusa Basin Watershed Coordinator Project No. 2850-01 983 University Avenue, Building D Los Gatos, CA 95032 Ph: 408.458.3200 F: 408.458.3210

LIST OF PREPARERS REPORT COMPILATION, BIOLOGY, LAND USE, AND SOCIAL CHARACTERISTICS Daniel Stephens, B.S., Principal-in-Charge Patrick Reynolds, M.S., Senior Restoration Ecologist Maximilliano Busnardo, M.S., Project Manager Matthew Ramsay, M.S., Restoration Ecologist John Sterling, B.A., Wildlife Ecologist Catherine Little, M.S., Plant Ecologist Samatha Moturi, M.S., GIS Specialist PHYSICAL PROCESSES (SOILS, GEOLOGY, GEOMORPHOLOGY, AND HYDROLOGY) G. Mathias Kondolf, Ph.D., Principal Geomorphologist Matt Smeltzer, P.E., M.L.A., Geomorphologist (with Geomorph) WATER QUALITY Blankinship & Associates Michael S. Blankinship, P.E., Project Manager Stephen Burkholder, B.S., Staff Biologist i

TABLE OF CONTENTS EXECUTIVE SUMMARY... 1 INTRODUCTION... 1 Overview... 1 Assessment Purpose... 1 FINDINGS... 2 Land Use and Social Characteristics... 2 Physical Processes (Geology, Geomorphology, Soils, Hydrology)... 3 Water Quality... 7 Biological Processes... 8 WATERSHED ACTION ITEMS... 9 INTRODUCTION... 11 GENERAL WATERSHED DESCRIPTION AND GEOMORPHIC SETTING... 11 ASSESSMENT PURPOSE AND STRUCTURE... 12 STAKEHOLDER ORGANIZATION AND PROCESS... 13 CLIMATE... 17 LAND USE AND SOCIAL CHARACTERISTICS... 24 HISTORICAL CONDITIONS AND TEMPORAL CHANGE... 24 Scope and Methods... 24 Watershed Community Characteristics (Demography and Economy Overview)... 24 Distribution of Communities and Transportation Systems... 27 Land-use and Agricultural Cropping Patterns... 27 EXISTING CONDITIONS... 31 Scope and Methods... 31 Watershed Community Characteristics... 32 Land-use Patterns, Zoning, Plans, and Policies (City and County)... 39 Easements (Agricultural, Conservation, etc.)... 46 Soil Class Effectiveness in Regard to Agricultural Preservation... 47 Agricultural Cropping Patterns and Irrigation Practices... 47 U. S. Fish and Wildlife Service Refuges... 50 GEOLOGY... 58 GEOLOGIC SETTING OF THE COLUSA BASIN WATERSHED... 58 Generalized Geologic Section... 58 Coast Range Foothills... 59 Tertiary Tehama Formation... 60 Older and Younger Alluvium... 66 Geologic Description of the Alluvial Units... 68 Valley Terraces... 71 Colusa Basin... 76 CASE STUDY: NORTH BRANCH SAND CREEK... 79 GEOMORPHOLOGY... 107 GEOMORPHIC SETTING OF THE COLUSA BASIN WATERSHED... 107 Available Geomorphology Data... 107 Fluvial Geomorphology of Colusa Basin Watershed Streams... 109 Influences of Geologic Structure on Colusa Basin Watershed Streams... 113 ii

Sediment Runoff and Transport... 115 Effects of Human Activities on Valley Flat Streams... 116 Effects of Human Activities on Foothill Streams... 116 SOILS... 131 OVERVIEW... 131 Scope and Methods... 131 GENERAL DESCRIPTION OF THE SOILS OF COLUSA BASIN WATERSHED... 132 The General Soil-type Classification of Storie and Weir (1951)... 132 Influence of Geologic Parent Material on Soil Formation... 134 Relation between Older Geomorphic Units and Older Soils... 134 General Description of Soils Occurring on the Typical Geomorphic Surfaces in the Watershed... 136 Examples of Soil-type Patterns on the Landscape... 138 General Soil Maps from County Soil Surveys... 139 Effects of Human Activities on Alkali Soils... 142 Effects of Human Activities on Soil Erosion... 144 CASE STUDY: NORTH BRANCH SAND CREEK... 148 SURFACE WATER HYDROLOGY... 160 OVERVIEW... 160 Available Colusa Basin Watershed Hydrology Studies and Data... 160 Summary Analysis of Foothill Stream Hydrology Data... 164 Effects of Human Activities on Foothill Stream Hydrology... 166 GROUNDWATER HYDROLOGY... 170 GROUNDWATER SUBAREAS... 170 Historical Groundwater Studies and Data... 173 Current Groundwater Management... 174 Groundwater Level Trends... 175 Representative Period of Record Groundwater Hydrographs... 176 Land Subsidence... 177 FLOOD MANAGEMENT... 189 Pre-1850 Sources and Patterns of Flood Waters in the Colusa Basin Watershed... 190 Sacramento River Flood Chronology Adapted from Kelley (1989)... 191 Failure of Early Privately Constructed Flood Protections... 192 Sacramento River Flood Chronology... 195 Reflections on the Outcomes of Early Flood Control Efforts... 197 Sacramento River Flood Control Project... 198 Description of Flood Control and Drainage Facilities... 199 Structural and Non-structural Projects for Relieving Residual Flooding Problems in the Watershed... 201 Ongoing Efforts to Reduce Residual Flooding... 204 WATER QUALITY... 216 HISTORICAL CONDITIONS... 216 Prior to Euro-American Contact (pre-1850)... 216 Post Euro-American Contact (post-1850)... 216 Surface Water... 216 Groundwater... 219 iii

EXISTING CONDITIONS... 220 Background... 220 Surfacewater... 220 Groundwater... 224 BIOLOGY... 226 HISTORICAL CONDITIONS AND TEMPORAL CHANGE... 226 Overview... 226 Data Sources and Methods... 226 Vegetation at Time of Settlement... 227 Anthropogenic Changes to Vegetation... 229 Wildlife... 231 Invasive Plants... 232 EXISTING CONDITIONS... 232 Biotic Habitats (Vegetation and General Wildlife Use by Habitat Type)... 232 Special-status Species (Plants and Wildlife)... 259 Invasive Plants... 270 Regulated Habitats and Permitting Overview... 286 DATA GAPS... 304 LAND-USE... 304 Updated General Plans for each County in the Watershed... 304 GEOMORPHOLOGY... 304 Fluvial Geomorphology for Stream Restoration and Bank Stabilization Design... 304 HYDROLOGY... 305 Mean Daily Flow Data... 305 Peak Flow Data... 306 Water Budget... 306 Flood Management... 306 BIOLOGY... 307 Vegetation... 307 Wildlife... 308 WATERSHED ACTION ITEMS... 310 NEXT STEPS TOWARD DEVELOPMENT OF A WATERSHED MANAGEMENT PLAN... 310 Preparation of an Integrated Watershed Management Plan... 310 Initial Identification of Stakeholder Resource Issues and Goals... 312 EXAMPLE PROJECT IDEAS... 313 Foothill Streams Creek Bank Stabilization and Riparian Habitat Restoration Projects 313 Oak Woodland Habitat Management... 314 Wetland and Riparian Management and Restoration Projects... 314 REFERENCES... 315 PERSONAL COMMUNICATIONS... 328 FIGURES: INTRODUCTION Figure 1. Vicinity... 14 iv

Figure 2. Subwatersheds and Major Drainages... 15 Figure 3. Elevation... 16 LAND USE Figure 1. Ownership... 52 Figure 2. Land Use... 53 Figure 3. Biologically Significant Areas... 54 Figure 4. Groundwater Recharge Zones... 55 Figure 5. Potentially Restorable Wetlands... 56 Figure 6. Williamsons Act Lands...57 GEOLOGY Figure 1. Section of Underlying Geologic Structure... 82 Figure 2. General Geologic Section near Grimes... 83 Figure 3. Oblique Aerial Photo of the Coast Range Foothills... 84 Figure 4. Excerpts of Geologic Maps of the Colusa Basin Watershed... 85 Figure 5. 1907 Topographic Map of Zamora, California... 90 Figure 6. Cache Creek Slough at Knights Landing Ridge... 91 Figure 7. 1949 Topographic Map of Funks Creek... 92 Figure 8. Map of Sacramento River... 93 Figure 9. Reproductions from 1925 Topographic Maps of the Sacramento Valley... 94 Figure 10. Detail Reproduced from 1840s Jimeno Land Grant Map... 96 Figure 11. Photo of Sand Creek Road Crossing Upstream... 97 Figure 12. Photo of Downstream Sand Creek Road Downstream... 98 Figure 13. Sand Creek Longitudinal Profile of Elevation, Geology, and Soils... 99 Figure 14. North Branch Sand Creek Foothill Valley Geologic Section... 100 Figure 15. North Branch Sand Creek Pleistocene Fanhead Geologic Section... 101 Figure 16. North Branch Sand Creek Holocene Fan Apex Geologic Section... 102 Figure 17. North Branch Sand Creek Distal Alluvial Fan Geologic Section... 103 Figure 18. North Branch Sand Creek Topography, Soils, and Geology Map near the Foothill Front... 104 Figure 19. North Branch Sand Creek Topography, Soils, and Geology Map near the Distal Alluvial Fan... 105 Figure 20. Colusa Basin Topography, Soils, and Geology Details near Grimes... 106 GEOMORPHOLOGY Figure 1. Photo from Hahn Road to Colusa Basin Drain... 123 Figure 2. Photo of Whiskey Creek... 124 Figure 3. Photo of Clarks Ditch, Petroleum Creek, Looking Downstream... 125 Figure 4. Photo of Petroleum Creek Looking Upstream... 126 Figure 5. Photo of Remnant of North Fork Elk Creek Looking Downstream... 127 Figure 6. Photo of Stone Corral Creek Looking Downstream... 128 Figure 7. Photo of Stone Corral Creek Looking Downstream during High Runoff Conditions 129 Figure 8. Sand Creek Looking Upstream... 130 SOILS Figure 1. Photocopy of Generalized Soil Map... 151 Figure 2. General Soil Map... 152 Figure 3. Typical Soil Patterns... 153 Figure 4. General Soil Map of Yolo County... 154 v

Figure 5. General Soil Map of Colusa County... 155 Figure 6. General Soil Map of Glenn County... 156 Figure 7. Saline-alkali Soils in Eastern Glenn County... 157 Figure 8. Hydrologic Soil Groups... 158 Figure 9. Soil Permeability in Sacramento Valley... 159 HYDROLOGY Figure 1. Colusa Basin Drainage District Irrigation Season Water Budget for 1977... 167 Figure 2. Colusa Basin Drainage District Irrigation Season Water Budget for 1980... 168 Figure 3. Colusa Basin Drainage District Irrigation Season Water Budget for 1988... 169 GROUNDWATER Figure 1. Changes in Groundwater Levels Spring 1975-Spring 1988... 179 Figure 2. Groundwater Contour Map Spring 1988... 180 Figure 3. Change in Groundwater Elevation Spring 1988-Fall 1988... 182 Figure 4. Representative Groundwater Well Hydrographs 1970-1988... 183 Figure 5. Representative Groundwater Well Hydrographs 1963-2008... 184 Figure 6. Areas of Historical Land Subsidence, 1926-1970... 188 FLOOD MANAGEMENT Figure 1. Detail from 1904 Plan for Sacramento Valley Flood Control... 209 Figure 2. Detail from 1940 Illustration of February-March 1940 Flood... 210 Figure 3. Detail from 1940 Map of the Areas Inundated by the Flood of February-March 1940... 211 Figure 4. Existing Flood Control Features and FEMA Map... 212 Figure 5. Historically Flooded Areas in the Willows Area... 215 BIOLOGY Figure 1. Pre-1900 Historic Vegetation Map... 290 Figure 2. 1945 Historic Vegetation Map... 291 Figure 3. 1995 Historic Vegetation Map... 292 Figure 4. Vegetation Map... 293 Figure 5. CNDDB Plant Records North... 294 Figure 6. CNDDB Plant Records South... 295 Figure 7. CNDDB Animal Records North... 296 Figure 8. CNDDB Animal Records South... 297 Figure 9. Barbed Goatgrass... 298 Figure 10. Giant Reed... 299 Figure 11. Medusahead... 300 Figure 12. Purple Starthistle... 301 Figure 13. Perennial Pepperweed... 302 Figure 14. Saltcedar... 303 TABLES: CLIMATE Table 1. Temperature and Precipitation Recorded in the Period 1961-1990 at Colusa and East Park Reservoir; Adapted from Reed 2006... 19 Table 2. Freeze Dates in Spring and Fall Recorded for the Period 1961-1990; Adapted from Reed 2006.... 21 vi

Table 3. Growing Season Recorded for the Period 1961-1990; Adapted from Reed 2006... 21 Table 4. Temperature and Precipitation Recorded in the Period 1971-2000 at Colusa... 22 Table 5. Growing Season Recorded at Colusa for the Period 1971-2000.... 23 LAND USE Table 1. Key Dates in the History of the Colusa Basin Watershed.... 25 Table 2. Rice Acreage 1913-1919.... 30 Table 3. Historic Crop Acreage Based on County Crop Reports for the Years Shown.... 30 Table 4. Demographic Statistics of 3 County Study Area and Local Communities... 35 Table 5. Demographic Statistics of 3 County Study Area and Local Communities... 36 Table 6. Land Uses in Colusa Basin Watershed... 40 Table 7. Land Use Proportions in Colusa County circa 1989... 43 Table 8. Projected Land Use Proportions in Colusa County in 2010.... 43 Table 9. Soil Class Data by Percent for Each of the 3 Counties within the Colusa Basin Watershed.... 48 Table 10. Soil Class Data for Each of the 3 Counties within the Colusa Basin Watershed in Acres by County.... 48 Table 11. Gross Agricultural Production Value of the Top 10 Commodities for Each of the 3 Counties in the Colusa Basin Watershed... 49 SOILS Table 1. Estimated Sediment Yields from Foothill Subwatersheds.... 148 HYDROLOGY Table 1. Historical Stream Gage Data Summary... 162 Table 2. Colusa Basin Drainage District Irrigation Season Water Budgets for 1977, 1980, and 1988... 164 BIOLOGY Table 1. Wildlife Species in Each WHR Landcover Type in the Colusa Basin Watershed... 242 Table 2. Biodiversity Indices, Species Richness, for Each Landcover Type in the Colusa Basin Watershed.... 255 Table 3. Special-Status Wildlife Species, Their Status, and Potential Occurrence in the Colusa Basin Watershed.... 261 Table 4. Special-status Wildlife Species in Each WHR Landcover Type in the Colusa Basin Watershed.... 266 Table 5. Special-status Plant Species, Their Status, and Potential Occurrence in the Colusa Basin Watershed.... 271 Table 6. Invasive Plant Species of Particular Management Concern in Colusa Basin Watershed.... 282 WATERSHED ACTION ITEMS Table 1. Preliminary Identification of Stakeholder Resource Issues and Goals... 312 APPENDICES Appendix 1. Introduction. List of Acronyms and Abbreviations... 329 Appendix 2. Introduction. Technical Advisory Committee Members... 332 Appendix 3. Introduction. Stakeholder Interview Summaries... 335 Appendix 1. Land Use. DWR Standard Land Use Legend... 378 Appendix 2. Land Use. Definitions of Important Farmland Categories... 395 vii

Appendix 1. Hydrology. Complete Period of Record Annual Hydrographs of Mean Daily Flow Measured at Gages in the Colusa Basin Watershed... 401 Appendix 1. Biology. The Central Valley Historic Mapping Project Sources and Methods... 431 Appendix 2. Biology. Plant Species Mentioned in the Text... 441 Appendix 3. Biology. Animal Species Referenced in the Text... 445 viii