Over the decades, numerous studies and projects have been completed by the Green Lake Association and other partners regarding Big Green Lake. These projects informed our practices to protect the water quality of Green Lake and its watershed. To gain a better understanding of this work, take a look below at our completed research studies, ongoing studies, and ongoing monitoring.

You can also find all known studies compiled on the Nelson Institute's website here.



  • 2021, US Geological Survey and Michigan Technological University, Diagnostic and Feasibility Study Findings: Water Quality Improvements for Green Lake, Wisconsin (here)

  • 2020, Upper Fox Wolf Total Maximum Daily Load (here)

    • Prepared for: US EPA & ​Wisconsin DNR 

  • 2019, Fuller, Sarah: “Temporal and spatial variation of nutrients and sediment in the marshes of Green Lake” (here

  • 2016, Delta Institute: “The Green Lake Watershed: Phosphorus Prioritization Tool” (here)

  • 2016, WI Department of Natural Resources: "Green Lake Fisheries Survey Summary Report" (here)

  • 2015, Lake Management Plan (here)

  • 2014, Stream survey (here)



  • Legacy Phosphorus in the Watershed of Wisconsin's Deepest Lake by Rachel Johnson, UW-Madison: Department of Biological Systems Engineering and Nelson Institute (WATCH HERE)

  • A Changing Lake: Addressing Low Dissolved Oxygen & High Phosphorus in Wisconsin's Deepest Natural Inland Lake, USGS/Michigan Technological University (WATCH HERE)

    • Presenters:

      • Stephanie Prellwitz, Executive Director, Green Lake Association

      • Dale Robertson, Research Hydrologist, U.S. Geological Survey Wisconsin Water Science Center

      • Cory McDonald, Assistant Professor of Environmental Engineering, Michigan Technological University




Big Green Lake is the deepest natural lake in Wisconsin. Changes in agriculture and urban development have altered the nutrient loading from the watershed and affected the water quality of the lake. Thanks to the Green Lake Sanitary District, this project is quantifying the amount of phosphorus and sediment delivered to Green Lake, measuring its water quality, and providing information about how the lake responds to input changes.


The Water Action Volunteers Stream Monitoring Program (WAV) incorporates three levels of participation for citizen scientists who are interested in monitoring local streams: Introductory (Level 1), Status and Trends (Level 2), and Special Projects Monitoring (Level 3).


A primary objective of introductory monitoring is to increase public understanding of watersheds and how human uses of the land impact stream quality, while building a baseline of basic water quality information. Data collected help to identify acute issues in wadeable streams.