Eagle River Chain of Lakes Vilas-Oneida Counties, Wisconsin Comprehensive Management Plan December 2019 Sponsored by: Eagle River Chain of Lakes Association WDNR Grant Program AEPP-388-13; AEPP-433-14; AEPP477-16; AEPP-500-17 Onterra, LLC 815 Prosper Road De Pere, WI 54115 920.338.8860 www.onterra-eco.com Eagle River Chain of Lakes Vilas & Oneida Counties, Wisconsin Comprehensive Management Plan December 2019 Created by: Brenton Butterfield, Tim Hoyman, Eddie Heath, Todd Hanke, and Josephine Barlament Onterra, LLC De Pere, WI Funded by: Eagle River Chain of Lakes Association Wisconsin Dept. of Natural Resources Lakes Grant Program (AEPP-388-13; AEPP-433-14, AEPP-477-16, & AEPP-500-17) Acknowledgements This management planning effort was truly a team-based project and could not have been completed without the input of the following individuals: Eagle River Chain of Lakes Planning Committee The Planning Committee was comprised of riparian property owners from the following lakes: Cranberry Lake Eagle Lake Lynx Lake Catfish Lake Scattering Rice Lake Duck Lake Voyageur Lake Otter Lake Yellow Birch Lake Watersmeet Lake Eagle River Chain of Lakes Comprehensive Management Plan 1 TABLE OF CONTENTS 1.0 Introduction ............................................................................................................................................ 4 2.0 Stakeholder Participation ....................................................................................................................... 6 3.0 Results & Discussion ........................................................................................................................... 10 3.1 Lake Water Quality ......................................................................................................................... 10 3.2 Watershed Assessment .................................................................................................................... 28 3.3 Shoreland Condition ........................................................................................................................ 35 3.4 Aquatic Plants .................................................................................................................................. 46 3.5 Aquatic Invasive Species in the Eagle River Chain ......................................................................... 77 3.6 Fisheries Data Integration ................................................................................................................ 79 4.0 Summary and Conclusions................................................................................................................... 79 5.0 Implementation Plan ............................................................................................................................ 92 6.0 Methods.............................................................................................................................................. 115 7.0 Literature Cited .................................................................................................................................. 117 FIGURES Figure 2.0-1. Select survey responses from the Eagle River Chain Stakeholder Survey............................. 8 Figure 2.0-2. Select survey responses from the Eagle River Chain Stakeholder Survey, continued ........... 9 Figure 3.1-1. Wisconsin Lake Natural Communities................................................................................. 14 Figure 3.1-2. Location of the Lower Eagle River Chain of Lakes within the ecoregions of Wisconsin. .. 15 Figure 3.1-3. Lower Eagle River Chain of Lakes average summer near-surface total phosphorus concentrations and median total phosphorus concentrations from comparable lakes. ............................... 17 Figure 3.1-4. Lower Eagle River Chain of Lakes average summer chlorophyll-α concentrations and median chlorophyll-α concentrations for comparable lakes. ................................................................................... 18 Figure 3.1-6. Lower Eagle River Chain of Lakes average summer Secchi disk transparency and median Secchi disk transparency values for comparable lakes. .............................................................................. 20 Figure 3.1-7. Lower Eagle River Chain of Lakes true color values. ......................................................... 20 Figure 3.1-10. Lower Eagle River Chain of Lakes mid-summer nitrogen to phosphorus ratios. .............. 23 Figure 3.1-11. Lower Eagle River Chain of Lakes and comparable lakes Trophic State Index values. .... 23 Figure 3.1-12. Lower Eagle River Chain of Lakes mid-summer pH values. ............................................. 24 Figure 3.1-13. Lower Eagle River Chain of Lakes alkalinity values and acid rain sensitivity ranges. ..... 25 Figure 3.1-14. Lower Eagle River Chain of Lakes susceptibility to zebra mussel survivability and establishment based on calcium concentration. .......................................................................................... 26 Figure 3.1-15. Stakeholder survey response Question #13. ....................................................................... 27 Figure 3.1-16. Stakeholder survey response Question #14. ....................................................................... 27 Figure 3.2-1. Lower Eagle River Chain of Lakes watershed and land elevation. ...................................... 30 Figure 3.2-2. Lower Eagle River Chain of Lakes proportion of land cover types used in WiLMS modeling. Based upon National Land Cover Database (NLCD – Fry et. al 2011). ..................................................... 31 Figure 3.2-3. Lower Eagle River Chain of Lakes watershed land cover types in acres............................. 33 Figure 3.2-4. Lower Eagle River Chain of Lakes watershed to lake area ratios. ........................................ 33 Figure 3.2-5. Lower Eagle River Chain of Lakes estimated water residence times. Estimated with WiLMS. .................................................................................................................................................................... 34 Figure 3.2-6. Lower Eagle River Chain of Lakes measured versus WiLMS-predicted growing season mean (GSM) total phosphorus concentrations. .................................................................................................... 34 Document Information Eagle River Chain of 2 Lakes Association Figure 3.3-1. Shoreline assessment category descriptions. ........................................................................ 42 Figure 3.3-2. Lower Eagle River Chain of Lakes shoreland condition...................................................... 43 Figure 3.3-4. Lower Eagle River Chain of Lakes total number of coarse woody habitat (CWH) pieces per shoreline mile. ............................................................................................................................................. 44 Figure 3.4-1. Aquatic plant rake fullness ratings. ...................................................................................... 56 Figure 3.4-2. Spread of Eurasian watermilfoil within WI counties. ........................................................... 59 Figure 3.4-3. Frequency of occurrence of aquatic vegetation, native and non-native Eurasian watermilfoil (EWM), in the Lower Eagle River Chain of Lakes from 2005-2017. N = 3,669. Decline in native vegetation is believed to be due to decline in chain-wide water clarity. ...................................................................... 63 Figure 3.4-4. Recorded maximum depth of aquatic plant growth in the Lower Eagle River Chain of Lakes from 2005/06, 2012, and 2017. Decline in maximum depth of aquatic plant growth is due to reduction in chain-wide water clarity over this period. ................................................................................................... 63 Figure 3.4-5. Eagle River Chain of Lakes littoral frequency of occurrence of select aquatic plant species from NEI 2005/06, Onterra 2012 and 2017 point-intercept surveys........................................................... 64 Figure 3.4-6. Lower Eagle River Chain of Lakes individual lake and chain-wide littoral frequency of occurrence of Eurasian watermilfoil from 2005/06, 2012, and 2017 point-intercept surveys. ................... 66 Figure 3.4-7. Lower Eagle River Chain of Lakes 2012 and 2017 native species richness. ....................... 67 Figure 3.4-8. Lower Eagle River Chain of Lakes average coefficients of conservatism. .......................... 69 Figure 3.4-9. Lower Eagle River Chain of Lakes Floristic Quality Index values. ..................................... 70 Figure 3.4-10. Lower Eagle River Chain of Lakes Simpson’s Diversity Index. ....................................... 71 Figure 3.4-11. Lower Eagle River Chain of Lakes emergent and floating-leaf aquatic plant community composition. ................................................................................................................................................ 72 Figure 3.4-12. Acreage of mapped EWM colonies within the Lower Eagle River Chain of Lakes from 2007-2017. Created using data from Onterra Late-Season EWM Peak-Biomass Survey data. ................ 74 Figure 3.4-13. Lower Eagle River Chain of Lakes individual lake and chain-wide littoral frequency of occurrence of Eurasian watermilfoil from 2005/06, 2012, and 2017 point-intercept surveys. ................... 74