Eden Area Watershed Assessment December 2012 Eden Area Watershed Assessment Prepared By Piedmont Triad Regional Council Cy Stober, Water Resources Manager Joy Fields, Environmental Educator Elizabeth Jernigan, Environmental Outreach Coordinator Malinda Ford, GIS Manager Supported By North Carolina Clean Water Management Trust Fund December 2012 Table of Contents INTRODUCTION ................................................................................................................................... 1 SECTION 1: STAKEHOLDER PROCESS ................................................................................................... 12 Watershed Stakeholder Committee ...................................................................................................................... 12 Technical Services ...................................................................................................................................................... 13 SECTION 2: WATERSHED CHARACTERIZATION ................................................................................... 14 Geography ................................................................................................................................................................. 14 Geology ...................................................................................................................................................................... 16 Soils .............................................................................................................................................................................. 19 Topography ................................................................................................................................................................ 27 Surface Hydrology .................................................................................................................................................... 31 Floodplains and Wetlands ...................................................................................................................................... 35 Ecological Habitat ..................................................................................................................................................... 39 Watershed Delineation ............................................................................................................................................ 44 SECTION 3: NC DIVISION OF WATER QUALITY (DWQ) SUMMARY OF EXISTING MONITORING DATA .. 46 Biological Monitoring ................................................................................................................................................ 52 Water Chemistry Monitoring ................................................................................................................................... 53 Water Chemistry Monitoring Summaries .............................................................................................................. 55 Dissolved Oxygen & pH .................................................................................................................................... 55 Turbidity ........................................................................................................................................................... 56 Fecal Material ................................................................................................................................................... 62 Nutrients .......................................................................................................................................................... 68 Water Quality Data Summary ............................................................................................................................... 73 SECTION 4: REVIEW OF LOCAL GOVERNMENT CODES, ORDINANCES, RULES, AND PROGRAMS .......... 74 Watershed Planning ................................................................................................................................................. 76 Watershed Protection ............................................................................................................................................... 77 Technique Description ............................................................................................................................................... 77 New Construction ....................................................................................................................................................... 77 Construction Inspections and Enforcement ............................................................................................................. 77 BMP Maintenance ...................................................................................................................................................... 77 Agricultural BMPs ....................................................................................................................................................... 77 Septic System Maintenance ..................................................................................................................................... 77 Low-Impact Development (LID) ............................................................................................................................... 77 Forestry Guidelines ................................................................................................................................................... 77 Illicit Discharge Detection and Elimination (IDDE) ................................................................................................ 77 Riparian Buffers ......................................................................................................................................................... 77 Water Quality Monitoring ....................................................................................................................................... 77 Watershed Restoration ............................................................................................................................................ 77 Conservation Easements and Acquisitions ............................................................................................................. 77 Outreach, Education and Public Involvement ....................................................................................................... 77 Comprehensive and Land Development Planning ............................................................................................... 78 Zoning ............................................................................................................................................................... 82 Subdivisions ...................................................................................................................................................... 84 Water Supply Watersheds ............................................................................................................................... 84 Development Requirements ..................................................................................................................................... 88 Site Design ........................................................................................................................................................ 88 Density Regulations .......................................................................................................................................... 88 Parking Lot Regulations & Landscaping ........................................................................................................... 89 Environmental Considerations .................................................................................................................................. 91 Soils .................................................................................................................................................................. 91 Topographic Slope ............................................................................................................................................ 92 Floodplain Regulations ..................................................................................................................................... 95 Aquatic Buffers ................................................................................................................................................. 96 Stormwater Management Practices ....................................................................................................................... 97 Design Criteria .................................................................................................................................................. 97 Low Impact Development (LID) ........................................................................................................................ 98 Erosion and Sediment Control ....................................................................................................................... 100 Inspections, Maintenance, Funding Agreements & Responsible Parties ....................................................... 101 Open Space Design & Management .................................................................................................................. 101 Agricultural