Water Quality in Mayflower Lake. N. Turyk Water Resource Scientist UW-Stevens Point

Transcription

1 Water Quality in Mayflower Lake N. Turyk Water Resource Scientist UW-Stevens Point

2 Tonight s discussion Water movement Water quality Zoning/Build-outs in the Watersheds Recommendations and Considerations

3 Where is water coming from? Near shore runoff and groundwater Surface watershed Groundwater watershed Water flows from higher to lower elevations Above ground Below ground

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5 Watersheds Mayflower Lake Surface Watershed: 1,652 acres Ground Watershed: 905 acres

6 What influences water quality? Land use practices Near shore activities Lake type Natural geology, soil, and topography Seasonal and environmental changes

7 Watersheds: Where the Water Originates Surface watershed Groundwater watershed

8 More Impervious Surface = More Runoff In a forest, rain soaks into the ground and is taken up by tree roots or moves down through the soil into the groundwater. When rain falls on impervious surfaces, it cannot soak into the ground and instead becomes runoff. Water (runoff) carries sediments and nutrients to the lake

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10 Shoreline Vegetation Reduces runoff Filters contaminants (sediment, nutrients, etc.) Provides habitat

11 Buffers Preserve Restore

12 Native Plants Have deeper roots that stabilize soil Lessen raindrop impact & erosion Stay upright in runoff to filter sediment Provide food & shelter for wildlife

13 Mayflower Lake Shoreland

14 Shoreland Disturbances

15 Types of Lakes Where/how are water, sediments, and nutrients moving in/out? How long does water stay in the lake? What kind of water quality can be expected?

16 Lake Type & Residence Time Mayflower Lake: approx 10 months

17 Water Quality Dissolve Oxygen Water Clarity and Color Nutrients (fertilizer) Minerals

18 Dissolved Oxygen Comes from atmosphere Important to aquatic organisms Changes with depth and season

19 Dissolved Oxygen Mayflower Lake DO (mg/l) Depth from surface (ft) Date 2/22/2011 4/25/2011 6/15/2011 7/7/2011 7/25/2011 8/17/2011 9/7/ /21/2011 6/20/2012 7/11/2012 8/1/2012 8/22/2012 9/15/ DO (mg/l)

20 Water Clarity Measure of light penetration in water Effected by Sediment Color Algae Controls depth aquatic plants can grow

21 Impacts of phosphorus Phosphorus added here - More rough fish, less game fish - More algae & vegetation - Obstructed navigation - Less attractive for swimming - Less oxygen

22 Phosphorus Grows Algae and Aquatic Plants! In a lake: 1 additional pound can grow 500 pounds of algae! Natural Sources Wetlands, soils, plants, animals Additions by Humans Fertilizer Manure/Septic systems/wastewater Erosion/Runoff

23 Nutrients Nitrogen and Phosphorus Grow plants and algae Occurs naturally Can be significantly increased by Exposing soil Lawn/garden/agricultural fertilizer Animal waste Septic systems Re-suspending bottom sediments In a lake: 1 additional pound can grow 500 pounds of algae!

24 Phosphorus Loading from Land Uses lbs. P/sq. mi./yr Forest Residential Agriculture Panuska and Lillie, 1995

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26 Phosphorus in Mayflower Lake Summer

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28 Algae species

29 Mayflower Lake Trophic Scorecard GOOD FAIR POOR Total P (Summer Average) 20 ppb Inorganic N (spring overturn) 0.3 ppm Chlorophyll a (Summer) Clarity 5.2 ppm 6.7 feet Algae Mesotrophic

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31 Mayflower Lake Other Parameters LOW MEDIUM HIGH Sulfate 2.9 ppm Chloride 3.6 ppm Potassium Sodium 1.1 ppm 0.9 ppm Atrazine <0.10 ppb

32 Land Management Practices to Improve Water Quality

33 Fertilizers containing phosphorus should not be used. Most soil has sufficient phosphorus concentrations to maintain a vegetative cover. If a soil is deficient in phosphorus it may be applied according to recommendations based on soil test results. Consider using native vegetation that doesn t require additional fertilizer.

34 Acknowledgements Marathon County Citizens and Lake Groups Marathon County Wisconsin Dept. of Natural Resources UWSP Water and Environmental Analysis Lab Algae - Dr. Bob Bell Aquatic Plants - Jen McNelly Cultural Survey - Dr. Kristin Floress Fisheries and Lake Maps - Drs. Ron Crunkilton and Justin Sipiorski Christine Koeller Sediment Cores - Dr. Samantha Kaplan and Paul Garrison (Wisconsin DNR) Shoreland Assessments and Build Outs - Dan McFarlane Water Quality and Watersheds Nancy Turyk, Paul McGinley, Ryan Haney, Danielle Rupp Zooplankton - Dr. Chris Hartleb UW-Stevens Point Undergraduate Students

35 Questions?