DRAFT Sonoma Creek Watershed Enhancement Plan An owner’s manual for the residents & landowners of the Sonoma Creek Watershed. Prepared by: The Sonoma Resource Conservation District in conjunction with the people of the Sonoma Creek Watershed and collaboration with the Sonoma Ecology Center. TABLE OF CONTENTS ACRONYMS .................................................................................................................................. 6 ACKNOWLEDGEMENT .............................................................................................................. 8 SECTION 1. INTRODUCTION AND BACKGROUND.............................................................. 9 CHAPTER 1: INTRODUCTION .............................................................................................. 10 PURPOSE OF THE SONOMA CREEK WATERSHED ENHANCEMENT PLAN....................................... 10 PROCESS FOR DEVELOPING THE PLAN ........................................................................................ 10 STAKEHOLDER GROUPS ............................................................................................................. 11 ORGANIZATION OF THE PLAN ..................................................................................................... 14 WATERSHED GOALS ................................................................................................................... 15 CHAPTER 2: WATERSHED DESCRIPTION AND HISTORY ............................................... 18 WATERSHED BOUNDARY OVERVIEW ......................................................................................... 18 CLIMATE .................................................................................................................................... 18 GEOLOGY AND SOILS ................................................................................................................. 19 Geologic History.................................................................................................................... 19 Watershed Geology ............................................................................................................... 19 WATER RESOURCES ................................................................................................................... 20 Hydrology .............................................................................................................................. 20 Surface Water Resources ....................................................................................................... 21 Groundwater Resources ......................................................................................................... 21 HABITAT TYPOLOGY AND NATURAL RESOURCES ...................................................................... 22 Oak-Dominated Forest, Woodland, and Savannah ............................................................ 22 Chaparral ............................................................................................................................ 23 Coniferous Forest and Redwood Grove ............................................................................. 23 Grasslands .......................................................................................................................... 23 Wetlands and Riparian Areas............................................................................................. 23 Special Status Plant Species .................................................................................................. 24 Invasive Plant Species ........................................................................................................... 26 1 FISH AND WILDLIFE ................................................................................................................... 27 Special Status Species ........................................................................................................... 27 Salmonid Fish: Steelhead Trout and Chinook Salmon .......................................................... 28 REGIONAL HISTORY AND CULTURAL RESOURCES ..................................................................... 29 Land Use ................................................................................................................................ 31 Historic Timeline ................................................................................................................... 31 Summary Timeline of Changes: ............................................................................................ 33 CURRENT LAND USE .................................................................................................................. 33 AGRICULTURE ............................................................................................................................ 33 Developed Areas .................................................................................................................... 34 Unincorporated Lands ........................................................................................................... 35 City of Sonoma Area ............................................................................................................. 35 PARKS AND OPEN SPACE ............................................................................................................ 36 FUTURE LAND USE ..................................................................................................................... 36 Land Use Buildout Projections .............................................................................................. 37 Urban Service Boundaries ..................................................................................................... 38 DEMOGRAPHICS AND ECONOMICS .............................................................................................. 38 SECTION 2. MANAGEMENT AND RECOMMENDATIONS ................................................ 40 CHAPTER 3. AGRICULTURAL AND RURAL SUSTAINABILITY ..................................... 41 AGRICULTURAL SUSTAINABILITY .............................................................................................. 41 AGRICULTURAL BENEFICIAL MANAGEMENT PRACTICES ........................................ 42 AGRICULTURAL REGULATIONS .................................................................................................. 42 RURAL BENEFICIAL MANAGEMENT PRACTICES ......................................................... 46 CHAPTER 4. CLIMATE CHANGE IMPACTS AND ADAPATION ......................................... 48 CLIMATE CHANGE IMPACTS IN CALIFORNIA ............................................................... 48 IMPACTS TO BIODIVERSITY AND HABITAT ................................................................... 49 FLOODS AND SEA LEVEL RISE ........................................................................................... 49 2 HEAT AND FIRE ..................................................................................................................... 49 AGRICULTURE AND LOCAL ECONOMY .......................................................................... 50 SONOMA COUNTY CLIMATE INITIATIVES ..................................................................... 51 CHAPTER 5. WATER QUANTITY ............................................................................................ 53 WATER DEMAND .................................................................................................................. 53 IMPORTED WATER ............................................................................................................... 53 SURFACE WATER ................................................................................................................. 54 GROUNDWATER.................................................................................................................... 54 RECYCLED WATER ............................................................................................................... 55 FACTORS IMPACTING WATER QUANTITY ..................................................................... 55 RECOMMENDED ACTIONS ................................................................................................. 56 CHAPTER 6. FLOODING ........................................................................................................... 58 HISTORIC AND CURRENT CONDITIONS .......................................................................... 58 Lower Sonoma Creek ............................................................................................................ 58 Upper Sonoma Creek............................................................................................................. 60 FLOOD MANAGEMENT AND ECOSYSTEM ENHANCEMENT OPPORTUTNITES ...... 60 CHAPTER 7. WATER QUALITY ....................................................................................... 63 BENEFICIAL USES ..................................................................................................................... 63 Total Maximum Daily Loads ..................................................................................................... 63 SEDIMENT ................................................................................................................................. 65 Water Quality Standards .................................................................................................... 65 Available Data