San Jose State University SJSU ScholarWorks Master's Theses Master's Theses and Graduate Research Fall 2009 Urban creek restoration, Adobe Creek, Santa Clara County, California. Chris D. Pilson San Jose State University Follow this and additional works at: https://scholarworks.sjsu.edu/etd_theses Recommended Citation Pilson, Chris D., "Urban creek restoration, Adobe Creek, Santa Clara County, California." (2009). Master's Theses. 3995. DOI: https://doi.org/10.31979/etd.mbv7-fnfb https://scholarworks.sjsu.edu/etd_theses/3995 This Thesis is brought to you for free and open access by the Master's Theses and Graduate Research at SJSU ScholarWorks. It has been accepted for inclusion in Master's Theses by an authorized administrator of SJSU ScholarWorks. For more information, please contact [email protected]. NOTE TO USERS This reproduction is the best copy available. IJMI URBAN CREEK RESTORATION, ADOBE CREEK, SANTA CLARA COUNTY, CALIFORNIA A Thesis Presented to The Faculty of the Department of Geology San Jose State University In Partial Fulfillment of the Requirements for the Degree Master of Science by Chris D. Pilson December 2009 UMI Number: 1484330 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMT Dissertation Publishing UMI 1484330 Copyright 2010 by ProQuest LLC. All rights reserved. This edition of the work is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 ©2009 Chris D. Pilson ALL RIGHTS RESERVED SAN JOSE STATE UNIVERSITY The Undersigned Thesis Committee Approves the Thesis Titled URBAN CREEK RESTORATION, ADOBE CREEK, SANTA CLARA COUNTY, CALIFORNIA by Chris D. Pilson APPRO.VED FQR THE DEPARTMENT OF GEOLOGY / Di\Stehn W. Williams, Department of Geology Date Dr. Paula Messina, Department of Geology Date _ --g^ Robert Van den Berg, Santa Clara Valley^Water District Date APPROVED FOR THE UNIVERSITY Vwf t^p^L-^ w\°y Associate Dean Office of Graduate Studies and Research Date ABSTRACT URBAN CREEK RESTORATION, ADOBE CREEK, SANTA CLARA COUNTY, CALIFORNIA by Chris D. Pilson Increased urban development has encroached upon and impacted Adobe Creek by constricting the route and volume of flow to predetermined corridors, often irrespective of the original creek morphology. The headwaters geology and human influences have contributed to the creek's disequilibrium. Channelization and instream modifications have segmented the creek system limiting the transfer of changes through the system. Located east of the San Andreas fault (SAF) in the Franciscan Complex, Adobe Creek flows from the eastern foothills of the Santa Cruz Mountains and empties into the San Francisco Bay. A geomorphic creek design was developed for the upper 335m(1100ft) of Reach 5. Upper Reach 5 extends from West Edith Avenue to downstream of the confluence with the Robleda Creek storm drain. This reach and the park upstream are prone to flooding during winter months. Upper Reach 5 is characterized by failing bank protection structures and a discontinuous artificially hardened bed. These features contributed to reduced flow capacity and increased the potential for property loss. The solution was based on a geomorphic assessment and survey from the upper watershed in Hidden Villa downstream to Foothill Expressway in Los Altos. Stable geomorphic characteristics for Adobe Creek include an entrenchment ratio greater than 2.4 and a stream gradient of 0.75. ACKNOWLEDGEMENTS An enormous debt of gratitude is owed to Dr. Williams of San Jose State University, thank you for your patience, unyielding support and for reigning in my tangential research. Thank you. A posthumous thank you to Seena Hoose, without whose guidance I might never have found the opportunity on Adobe Creek and at the District. Thanks to everyone in the former Stream Water Quality Unit; especially Rob Van den Berg, Dipankar Sen and Brett Calhoun. Thanks to everyone else at the District who has helped me track down information and for letting me tag along. A huge thanks goes to my family for their patience, understanding and unwavering belief in my success. v TABLE OF CONTENTS INTRODUCTION 1 Reach 5 Project Background 4 Scope of Research Project 10 GEOLOGIC AND GEOMORPHIC SETTING 10 General Location 10 Uplands Geologic Setting 13 Carbonate Influence 13 Natural Segmentation 23 Tectonism 23 Fault Bound Assemblages 25 Range-Front Faults 29 Valley Fill Materials and Subsurface Geology 34 Alluvial and Fluvial Deposits 34 Santa Clara Formation 37 Geologic Subareas 38 HUMAN INFLUENCE 47 A Creek by Many Names 47 Early Landuse 53 Agricultural Transition 54 Creek Modifications 58 Riparian Conditions 60 vi Segmentation 63 Suburbanization 65 Subsidence 67 1950's Flood Control 71 1970's Flood Control 73 1980's Flood Control 74 FIELD RESEARCH 74 Survey 74 Longitudinal Profile 79 Cross-Sections 80 Geomorphic Assessment 85 Manning's n 85 Pebble Count 86 Section Analyzer 87 Stable Reaches 92 ENGINEERING 100 Paleochannels 100 Transportation Corridor Modifications 103 Evolution of Project 104 FURTHER RESEARCH 105 CONCLUSIONS 106 REFERENCES CITED 109 vii LIST OF FIGURES Figure 1. General Location of Adobe Creek 2 2. Adobe Creek Reach 5 Location 3 3. Historic Flooding in Adobe Creek Reach 5 5 4. Aerial Photograph of Adobe Creek Upstream of Reach 5, 1956 6 5. Adobe Creek Flooding Edith Park, 1952 7 6. Upper Reach 5 Blue Line Limits 9 7. Upper Adobe Creek Watershed 11 8. Charleston Slough circa 1850 12 9. Average Annual Rainfall Dahl Ranch Rain Gauge 14 10. Average Monthly Rainfall at Dahl Ranch Gauge 15 11. Carbonate Build-up in Previous Century's Water Supply Pipe 17 12. Geologic Map of Adobe Creek 18 13. Cemented Forest Debris 19 14. Hardened Waterway 20 15. Adobe Creek Source 21 16. Geographic Features of the Santa Clara Valley 24 17. Regional Faults 26 18. Assemblages of Adobe Creek 27 19. Reverse Range-Front Faults, 1975 30 20. Reverse Range-Front Faults, 2000 31 viii LIST OF FIGURES (CON'T) 21. Stream Profile at Fault Crossing 33 22. Valley Cross-Section Location Map 35 23. Valley Cross-Section B-B' 36 24. Confined Aquifer and Surface Recharge Zones, Santa Clara Valley 39 25. Schematic Cross-Section of the Santa Clara Valley 40 26. Hydrogeologic Subareas of Western Santa Clara County... 42 27. Location ofVanBuren Well No. 2 and ShoupPark 43 28. Downstream-most Extent of the Natural Unmodified Channel 45 29. Trapezoidal Channel Downstream of El Camino Real 46 30. Lower Adobe Creek Channelized Flatlands 48 31. AllardtMapofl862 50 32. Thompson and West Index Map of 1876 51 33. Westdahl Map of 1897 52 34. Soils Map of Adobe Creek 55 35. Earthen Transition, Ephemeral Branches, Paleochannels and Sausals 57 36. Thompson and West Map of 1876 59 37. 1899 Palo Alto 30-Minute Quadrangle 61 38. Redwood Grove Nature Preserve 62 39. Adobe Creek Locked Segments 64 40. 1956 O'Keefe Avenue Bridge 66 41. 2004 O'Keefe Avenue Bridge 66 ix LIST OF FIGURES (CON'T) 42. Aerial Photograph of Edith Park, 1972 68 43. Subsidence Map of Santa Clara Valley 69 44. 1931 Election Poster 70 45. Depth to Groundwater, Population and Subsidence Graph 72 46. Adobe Creek Bypass Upstream of Interstate 280 75 47. Typical Channelized Section through Foothill College 76 48. Typical Bridge Crossing in Foothill College 77 49. 1931 West Edith Avenue Bridge 78 50. Cross-Section and Pebble Count Location Index Map 81 51. Hidden Villa Cross-Section and Pebble Count Locations 82 52. Lower Adobe Creek Cross-Section and Pebble Count Locations 83 53. Riffle Slope to dso Comparison 88 54. Cross-Section to dso Comparison 89 55. Hidden Villa Photograph Locations 93 56. Photograph of Upper Hidden Villa 94 57. View Downstream, Upstream of West Branch Confluence 96 58. Photograph of Middle Hidden Villa 97 59. Photograph of Lower Hidden Villa 98 60. Photograph of Shoup Park Vegetation 101 x LIST OF TABLES Table 1. Water Chemistry of Adobe Creek, Hardness 22 2. Industry Change in San Jose, California 56 3. Geomorphic Calculations 99 4. Alternative Designs Comparison 102 LIST OF APPENDICES Appendix A. Longitudinal Profiles 116 B. Cross-Sections 130 C. Pebble Counts 169 XI INTRODUCTION The goal of this project was to support a design for a stable creek in the upper portion of Adobe Creek Reach 5. This reach was plagued by instream erosion, extensive failing bank protection structures and reduced flow capacity. The geomorphic design was based on data from field measurements of the physical properties of Adobe Creek. Creek reaches free of indicators of incision or aggradation and lateral migration were considered stable. These stretches of creek were used as reference reaches to be studied then emulated. The design was to provide flood protection, increase riparian habitat and decrease hardscape. Approximately 1.5 percent of the overall length of the creek was addressed by this project. See Figure 1 for the location of Adobe Creek within Santa Clara County and Figure 2 for a close-up of Upper Reach 5, which extends approximately 335m(1100ft) downstream of the West Edith Avenue Bridge. Adobe Creek has a history of flooding from Reach 5 upstream through Edith Park. In a Los Altos History Show interview (Geschke, 1998) with Ruth Eleanor Cranston Fowle Cameron, a long-time resident of the Los Altos region, she described the creek behavior during the early 20th century in the area of Reach 5. Her family, the Cranstons, lived on a hill above the creek at the corner of Fremont and Campo Vista Lane.