Duncan and Grass Bays Watershed Management Plan October 2016 i Acknowledgements Thank you to Julia Kirkwood and Greg Goudy of the Michigan Department of Environmental Quality Nonpoint Source Program for their assistance with development of the Duncan and Grass Bays Watershed Management Plan. This NPS Pollution Control project has been funded wholly or in part through the Michigan Department of Environmental Quality’s Nonpoint Source Program by the United States Environmental Protection Agency under assistance agreement #C600E727-12 to Tip of the Mitt Watershed Council for the Duncan and Grass Bays: Watershed Management Development Project. The contents of the document do not necessarily reflect the views and policies of the United States Environmental Protection Agency or the Department of Environmental Quality, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use. Tip of the Mitt Watershed Council 426 Bay St. Petoskey, MI 49770 www.watershedcouncil.org MDEQ/EPA Approved October 2016 ii Table of Contents Project Partners ................................................................................................................................ ix Introduction ......................................................................................................................................1 What Is the Watershed Approach? ....................................................................................................... 1 Why the Duncan and Grass Bay Watershed? ....................................................................................... 2 The Environmental Protection Agency’s Nine Minimum Elements ...................................................... 3 Chapter 1: Duncan and Grass Bays Watershed ....................................................................................5 Climate .................................................................................................................................................. 6 Demographics ....................................................................................................................................... 6 Geology, Soils, and Groundwater ......................................................................................................... 6 Natural Communities .......................................................................................................................... 12 Wetlands ............................................................................................................................................. 18 Threatened, Endangered, and Species of Special Concern ................................................................. 25 Fisheries .............................................................................................................................................. 27 Land Use .............................................................................................................................................. 30 Recreation ........................................................................................................................................... 33 Enbridge Line 5 Pipeline ...................................................................................................................... 36 Zoning Assessment.............................................................................................................................. 37 Environmental Areas ........................................................................................................................... 40 Focus Groups within the Duncan and Grass Bays Watershed ............................................................ 41 Chapter 2: Water Quality Standards and Designated Uses of the State of Michigan ........................... 46 Chapter 3: Water Quality of Duncan and Grass Bays Watershed ........................................................ 50 Review of Existing Monitoring Data for the Grass and Duncan Bays Watersheds ............................. 50 Duncan Bay Tributaries ....................................................................................................................... 53 Chapter 4: Review of Nonpoint Source Pollution Inventories ............................................................. 63 Road/Stream Crossing Inventory ........................................................................................................ 63 Streambank Erosion Inventory ........................................................................................................... 68 Shore Survey ....................................................................................................................................... 71 Invasives Species ................................................................................................................................. 81 Stormwater Inventory ......................................................................................................................... 83 Land Use .............................................................................................................................................. 87 iii Chapter 5: Identification and Prioritization of Pollutants, Sources and Causes ................................... 89 Sediment Sources and Causes ............................................................................................................ 89 Nutrient Sources and Causes .............................................................................................................. 89 Sources and Causes of Other Pollutants ............................................................................................. 90 Critical Areas ............................................................................................................................ 92 Priority Areas ........................................................................................................................... 94 Protected Lands .................................................................................................................................. 94 Priority Parcels Process ............................................................................................................. 96 Chapter 6: Goals and Objectives ..................................................................................................... 100 Chapter 7: Watershed Protection Plan Implementation Steps ......................................................... 102 Overview of Implementation Tasks and Actions .............................................................................. 102 Proposed Best Management Practices (BMPs) ................................................................................. 102 BMP Effectiveness ............................................................................................................................. 104 Location of BMPs in the Watershed ................................................................................................. 105 Low-Impact Development ................................................................................................................. 105 Green Infrastructure ......................................................................................................................... 106 Implementation Steps ............................................................................................................ 107 Chapter 8: Information and Education Strategy .............................................................................. 121 Chapter 9: Monitoring Plan ............................................................................................................ 134 Surface Water Quality Monitoring .................................................................................................... 134 Shoreline and Streambank Surveys .................................................................................................. 134 Stormwater Monitoring .................................................................................................................... 134 Land Use monitoring ......................................................................................................................... 135 Road/Stream Crossing Monitoring ................................................................................................... 135 Land Protection and Management Monitoring ................................................................................ 135 Habitat Monitoring ........................................................................................................................... 135 Recreation, Human Health, and Safety Monitoring.......................................................................... 136 Groundwater Monitoring .................................................................................................................. 136 Wetland Monitoring ......................................................................................................................... 137 Aquatic Invasive Species ................................................................................................................... 137 Low Impact Development (LID) Monitoring ..................................................................................... 137 Socio-economic Monitoring 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