Arroyo Grande Creek Watershed Management Plan Update
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Arroyo Grande Creek Watershed Management Plan Update March 2009 Prepared for The Department of Fish and Game State of California This management plan was funded by the California State Department of Fish and Game Fisheries Restoration Grant Program. The contents of this document do not necessarily reflect the views and policies of the CDFG, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. Prepared by Central Coast Salmon Enhancement Table of Contents Executive Summary 1 Summary of Findings ......................................................................................................... 2 Introduction and Background 3 Introduction to the 2009 Update ....................................................................................... 3 Purpose and Need for the Plan .......................................................................................... 4 Watershed Overview .......................................................................................................... 5 History of Arroyo Grande Creek ...................................................................................... 8 History of Arroyo Grande Watershed Forum ............................................................... 11 Public Outreach Plan/Process ......................................................................................... 12 Goals & Objectives ........................................................................................................... 12 Sponsors ............................................................................................................................. 13 Existing Conditions 14 Physical Features and Processes ..................................................................................... 15 Topography ................................................................................................................................................. 15 Climate ....................................................................................................................................................... 15 Description of Current Conditions……………………………………………………..16 Geologic Setting ....................................................................................................................................... 16 Biology ..................................................................................................................................................... 25 Water Quality ........................................................................................................................................... 44 Cultural Resources .................................................................................................................................... 47 Land Use ................................................................................................................................................... 48 Social and Economic Demographics ........................................................................................................ 51 Critical Issues .................................................................................................................... 51 Water Quality ........................................................................................................................................... 51 Barriers to Fish Migration ........................................................................................................................ 54 Erosion and Sedimentation ....................................................................................................................... 65 Flood Protection ....................................................................................................................................... 67 Implementation 71 Approach to Implementing the Plan .................................................................................71 Benefits to Landowners and Community .........................................................................72 Recommended Projects ......................................................................................................72 Conduct Steelhead Restoration Planning ...................................................................................................... 72 Remove Exotic Species ................................................................................................................................ 76 Control Erosion to Reduce Sediment for Improved Water Quality .............................................................. 79 Promote Policy Planning and Education ....................................................................................................... 81 Status of Recommended Projects ......................................................................................88 Pending Changes to the Watershed ............................................................................90 Record of Watershed Activities and Project Treatments as Carried Out ..............91 Additional References about Activities and Treatments ....................................................................... 92 Regulatory Setting / Agency Jurisdiction ...................................................................93 Federal Agencies ................................................................................................................................... 93 State Agencies ....................................................................................................................................... 95 Local Agencies ...................................................................................................................................... 98 Resource Agencies – Non-Regulatory .........................................................................99 Federal Agencies ................................................................................................................................. 99 State Agencies ................................................................................................................................... 100 Local Agencies .................................................................................................................................. 101 Relationship to Other Existing Plans ........................................................................103 Conclusion 110 References 112 Endangered Species Recovery Plans and Federal Register Notices .................................................... 116 Acknowledgements 119 Agency Contact Information 121 Cover page: Arroyo Grande Creek, CCSE, 2004 Appendices A History of Arroyo Grande Creek Watershed B Geomorphic and Hydrologic Conditions of Arroyo Grande Creek C California Natural Diversity Database, USGS Quads for Oceano and Arroyo Grande D Stream Inventory for Arroyo Grande Creek E Volunteer Water Quality Monitoring Results F CCAMP Coastal Confluences Results G Census Trend 1970 to 2000 Summary Report and General Summary Report for Demographics of Zip Codes 93420 and 93445 H Community Questions and Answers for Critical Issues I Information on Types of Easements J Master Plan K Lower Arroyo Grande Creek and Lagoon Fishery and Aquatic Resources summary Monitoring Report L Watershed-wide Memorandum of Understanding M Summary of Fisheries Assessments in the Watershed List of Figures FIGURE 1. ARROYO GRANDE CREEK WATERSHED ..................................................................... 7 FIGURE 2. GEOLOGIC MAP OF ARROYO GRANDE CREEK WATERSHED .................................... 17 FIGURE 3. COVER AND SURFACE WATER ................................................................................. 24 FIGURE 4. LIFE CYCLE OF THE STEELHEAD TROUT .................................................................. 28 FIGURE 5. SAMPLE LOCATIONS AND GEOMORPHIC REACHES .................................................. 32 FIGURE 6. FISH SPECIES DISTRIBUTION, SNORKEL AND ELECTROFISHING SURVEYS ............... 33 FIGURE 7. DENSITY ESTIMATES FOR 1+ AND 2+ STEELHEAD .................................................... 34 FIGURE 8. WATER QUALITY MONITORING SITES ..................................................................... 45 FIGURE 9. LAND OWNERSHIP ................................................................................................... 50 FIGURE 10. FISH PASSAGE BARRIER - TWO CONCRETE DAMS ................................................. 54 FIGURE 11. FISH PASSAGE BARRIER – STREAM GAUGE ........................................................... 55 FIGURE 12. FISH PASSAGE BARRIER – CECCHETTI ROAD CULVERT ........................................ 57 FIGURE 13. FISH PASSAGE BARRIER – FOUR CULVERTS AT BIDDLE PARK .............................. 58 FIGURE 14. FISH PASSAGE BARRIER – ABANDONED DAM FOOTINGS ...................................... 59 FIGURE 15. FISH PASSAGE BARRIER – CONCRETE GRADE CONTROL WEIR ............................. 59 FIGURE 16. FISH PASSAGE BARRIER – LOS BERROS CREEK GAUGE ........................................ 60 FIGURE 17. FISH PASSAGE BARRIER – TAR SPRINGS CREEK CONCRETE WEIR ........................ 61 FIGURE 18. FISH PASSAGE BARRIER – TALLY HO CULVERT .................................................... 62 FIGURE 19. BEAVER DAM ........................................................................................................ 63 FIGURE 20. HISTORIC LOCATION OF FLOOD CHANNEL ...........................................................