Monterey Lake Improvement Study and Management Plan Allegan County, Michigan Provided for: Sandy Pines Recreational Community Sandy Pines Wilderness Trails, Inc. 2745 136th Ave. Hopkins, Michigan 49328 Prepared by: Restorative Lake Sciences Jennifer L. Jermalowicz-Jones, PhD Water Resources Director 18406 West Spring Lake Road Spring Lake, Michigan 49456 www.restorativelakesciences.com ©Restorative Lake Sciences, 2019 1 TABLE OF CONTENTS SECTION PAGE LIST OF FIGURES ................................................................................................................................... 4 LIST OF TABLES ..................................................................................................................................... 7 1.0 EXECUTIVE SUMMARY ............................................................................................................ 9 2.0 LAKE ECOLOGY BACKGROUND INFORMATION .................................................................... 10 2.1 Introductory Concepts ............................................................................................... 10 2.1.1 Lake Hydrology ................................................................................................ 10 2.1.2 Biodiversity and Habitat Health ...................................................................... 11 2.1.3 Watersheds and Land Use .............................................................................. 12 3.0 MONTEREY LAKE PHYSICAL & WATERSHED CHARACTERISTICS .......................................... 13 3.1 The Monterey Lake Basin .......................................................................................... 13 3.2 Monterey Lake Extended and Immediate Watershed and Land Use ....................... 17 3.3 Monterey Lake Land Use and Shoreline Soils ........................................................... 19 4.0 MONTEREY LAKE WATER QUALITY ....................................................................................... 21 4.1 Water Quality Parameters ......................................................................................... 22 4.1.1 Dissolved Oxygen ............................................................................................ 24 4.1.2 Water Temperature ........................................................................................ 24 4.1.3 Specific Conductivity ....................................................................................... 25 4.1.4 Turbidity, Total Dissolved Solids, and Total Suspended Solids ....................... 26 4.1.5 pH .................................................................................................................... 28 4.1.6 Total Alkalinity ................................................................................................. 29 4.1.7 Total Phosphorus and Ortho-Phosphorus ...................................................... 30 4.1.8 Total Kjeldahl Nitrogen and Total Inorganic Nitrogen .................................... 31 4.1.9 Chlorophyll-a and Algae .................................................................................. 32 4.1.10 Secchi Transparency ...................................................................................... 32 4.2 Monterey Lake Aquatic Vegetation Communities .................................................... 36 4.2.1 Monterey Lake Exotic Aquatic Macrophytes .................................................. 39 4.2.2 Monterey Lake Native Aquatic Macrophytes ................................................. 42 4.3 Monterey Lake Food Chain: Zooplankton and Macroinvertebrates ........................ 48 4.4 Monterey Lake Fishery Spawning Habitat ................................................................. 54 2 5.0 MONTEREY LAKE MANAGEMENT IMPROVEMENT METHODS ............................................ 56 5.1 Monterey Lake Aquatic Plant Management ............................................................. 56 5.1.1 Aquatic Invasive Species Prevention .............................................................. 56 5.1.2 Aquatic Herbicides and Applications .............................................................. 62 5.1.3 Mechanical Harvesting .................................................................................... 63 5.1.4 Benthic Barriers and Nearshore Management Methods ............................... 64 5.1.5 Diver Assisted Suction Harvesting................................................................... 65 5.2 Monterey Lake Water Quality Improvement ............................................................ 66 5.2.1 Laminar Flow Aeration and Bioaugmentation................................................ 66 5.2.2 Benthic Aluminum Applications ...................................................................... 68 5.2.3 Dredging .......................................................................................................... 69 5.2.4 Fishery Habitat Enhancement ......................................................................... 71 5.3 Monterey Lake Watershed Management ................................................................. 74 5.3.1 Monterey Lake Erosion and Sediment Control .............................................. 74 5.3.2 Monterey Lake Nutrient Source Control ........................................................ 90 6.0 MONTEREY LAKE PROJECT CONCLUSIONS AND RECOMMENDATIONS .............................. 91 7.0 SCIENTIFIC REFERENCES ........................................................................................................ 94 3 LIST OF FIGURES FIGURE PAGE 1. Aerial Photo of Monterey Lake (RLS, 2018) ..................................................................... 14 2. Monterey Lake Depth Contour Map (RLS, 2019) ............................................................ 15 3. Monterey Lake Sediment Hardness Map (RLS, 2019) ..................................................... 16 4. Monterey Lake Immediate Watershed Map (RLS, 2019) ................................................ 18 5. Monterey Lake Soils Map (NRCS-USDA data) .................................................................. 20 6. The Lake Eutrophication Process ..................................................................................... 22 7. Monterey Lake Deep Basin Water Quality Sampling Location Map (2019) .................... 23 8. Thermal Stratification Process ......................................................................................... 25 9. Changes in Mean Conductivity with Time in Monterey Lake (2009-2019) ..................... 26 10. Changes in Mean TDS with Time in Monterey Lake (2009-2019) ................................... 27 11. Changes in Mean pH with Time in Monterey Lake (2009-2019) ..................................... 28 12. Changes in Mean Total Alkalinity with Time in Monterey Lake (2009-2019) ................. 29 13. Changes in Mean TP with Time in Monterey Lake (2009-2019) ..................................... 30 14. Secchi Disk Measurement Diagram ................................................................................. 33 15. Changes in Mean Secchi with Time in Monterey Lake (2009-2019) ............................... 33 16. Monterey Lake Aquatic Vegetation Biovolume Map (June 28, 2019)............................. 38 17. Photo of Chara ................................................................................................................. 41 18. Photo of Thin-leaf Pondweed .......................................................................................... 41 19. Photo of Flat-stem Pondweed ......................................................................................... 41 20. Photo of Yellow Waterlily ................................................................................................ 41 21. Photo of Bladderwort ...................................................................................................... 41 4 22. Photo of Coontail ............................................................................................................. 41 23. Photo of American Pondweed ......................................................................................... 42 24. Photo of Illinois Pondweed .............................................................................................. 42 25. Photo of Cattails .............................................................................................................. 42 26. Photo of Spikerush ........................................................................................................... 42 27. Photo of Water Smartweed ............................................................................................. 42 28. Photo of Blue flag Iris ....................................................................................................... 42 29. Photo of Hybrid EWM ...................................................................................................... 43 30. Photo of Hybrid EWM Canopy ......................................................................................... 44 31. Distribution Map of EWM and Phragmites in Monterey Lake (2019) ............................. 45 32. Photo of a CLP .................................................................................................................. 46 33. Photo of Phragmites ........................................................................................................ 47 34. Photo of Phragmites in One Area of