Agency Reports

Sharing research that has been conducted in the Green Lake watershed is an essential component of lake management. This collection includes reports that have been developed by government agencies and educational institutions. Each report has a brief summary and a link to the full document.

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Green Lake County Farmland Preservation and Comprehensive Planning (2011)

Ken Jaworski, Martenson & Eisele, Inc.
This industry report summarizes the magnitude of the agricultural industry in Green Lake County in terms of job creation, tax revenue, property ownership, farm size, and farm type. As of 2013, agriculture is the dominant industry in the county, with 64% of Green Lake County land being used for agriculture. The presentation presents the changes that have occurred in Green Lake County’s agricultural industry over time and projects future population change in order to understand the trajectory of agricultural planning. Read »

Aquatic Vegetation

Green Lake Aquatic Plant Community Assessment (2015)

Brenton Butterfield, Eddie Heath et al., Onterra LLC
This 2014 comprehensive assessment of the aquatic plant communities in Green Lake summarizes data from a point-intercept survey that was funded by the Green Lake Sanitary District and the Wisconsin Department of Natural Resources. With over 3,000 sampling points, data collected included depth, substrate type, plant species, and species relative abundance. Within the lake, 34 aquatic plant species were located. Coontail (Ceratophyllum demersum) and hybrid water milfoil (Myriophylllum sibiricum X spicatum) were the most frequently encountered species, making up more than 50% of the plant community. The aquatic vegetation within the lake had an average conservatism of 6.2 and a Floristic Quality Index of 31, both of which were higher than the median values of lakes in the Southeastern Wisconsin Till Plains. This survey also contains results for estuaries surrounding Green Lake: Beyers Cove, City Millpond, County Marsh, and Silver Creek Estuary. Results are compared to past Green Lake aquatic plant community inventories, and the report specifies locations of non-native aquatic plant populations.

Climate Change

Wisconsin’s Changing Climate: Impacts and Adaptation (2011)

Elizabeth Katt-Reinders, Steve Pomplun, et al., Wisconsin Initiative on Climate Change Impacts (WICCI)
This report details the observed and projected effects of climate change on Wisconsin’s industry and ecosystems. The research described in chapters 3, 5, and the appendices predicts that Wisconsin’s lakes will experience shorter ice cover periods, increased evapotranspiration, increased flooding, and higher sediment loads. In order to prevent erosion, which would cause farmland degradation and water pollution, Wisconsin’s farmers will need to adapt in order to preserve their soil resources. Full text includes detailed explanations of these and more climate change effects.

The WICCI initiative also developed an interactive map so users can see which locations presently have a climate similar to what is predicted for Wisconsin within the next century. By the end of this century, using an average of available climate models and a scenario of high emissions, Green Lake is predicted to have a climate similar to what is currently observed 590 miles to the southwest around Wichita, Kansas. Explore the map.

Climate Wizard is another platform for visualizing impacts from climate change. This map allows users to specify different emission scenarios and climate models to see predicted temperature and precipitation changes over the next century. The map can show data at a global, national, and state scale.


Near Shore Fishes of Green Lake (2015)

Dave Marshall, Mark Sesing et al., Green Lake Sanitary District
This 2015 survey was a comprehensive nearshore inventory of nongame fish species and associated immature sportfish in Green Lake. There were 16 sampling sites around the lake and four within County K Marsh. Since 1928, 40 fish species have been reported within Green Lake, and this survey found 19 species. This data established baseline monitoring for County K Marsh, “fish sticks” habitat enhancements along the lake shoreline, and overall nearshore fish populations. The most common fish found were bluegill, rock bass, yellow bullhead, yellow perch, mimic shiner, largemouth bass, and smallmouth bass. Iowa darter and central mudminnow were collected for the first time since 1928. Fantail Darters and mottled sculpin were found for the first time. Overall, the survey resulted in relatively low to moderate numbers of fish in nearshore areas. It was recommended to resurvey in 2020.

The Whitefishes of Wisconsin’s Inland Lakes: The 2011-2014 Wisconsin Department of Natural Resources Cisco and Lake Whitefish Survey (2015)

John Lyons, Jeff Kampa et al., Wisconsin Department of Natural Resources
Beginning in 2011, WDNR undertook a survey of cisco and lake whitefish populations in the state’s inland lakes. These fish require cold, well-oxygenated water, and their current distribution and population status were poorly known. Cisco were captured from 94 of the 133 lakes sampled, and whitefish were captured from 6 of the 9 sampled systems. Sampling at Green Lake, in 2013, showed relatively high cisco populations. Lake whitefish are limited to the northern third of the state, so none were found in Green Lake.

Final Environmental Impact Statement for the Proposed Introduction and Stocking of Landlocked Salmon into Big Green Lake (2014)

Chuck Mirr, Phil Burkart et al., The Green Lake Coldwater Fishery Advisory Committee
This proposal to stock Landlocked Atlantic Salmon in Green Lake as a replacement for stocked domestic brown trout would have been appealing to anglers because of an added species of cold-water sport fish. In fall 2014, this proposal was opened for public comment. Evolving concerns relating to the negative impacts on the current fishery, especially the cisco population, proved large enough to postpone the project. The Department of Natural Resources determined that increased public support and more long-term fish monitoring would be required for this proposal to be implemented.


Microstratification and Oxygen Depletion in Green Lake, Wisconsin (2014)

Carl Watras, Wisconsin Department of Natural Resources
This study collected fine-scale vertical profiles of seven water quality variables (temperature, dissolved oxygen, dissolved carbon dioxide, pH, beam attenuation, Chl flourescense, and specific conductivity) at six stations. Researchers found a major metalimnetic oxygen minimum (MOM) and other minor oxygen minima. The metalimnion is the thermal layer of a lake where there is a large change in temperature; warmer water is above and cooler water is below. For this study, it was generally at a depth of 12 m. The oxygen minima were associated with other results suggesting heterotrophic activity by plankton. Modeling showed excess carbon dioxide levels in the deepest parts of the lake suggesting that anaerobic respiration may be an important process. Conclusions supported further focus on the lake’s microbiota and metabolism.

What Green Lake’s Sediments Tell us about its History (2002)

Paul Garrison, Wisconsin Department of Natural Resources
In 1999, sediment cores were extracted from 4 sites throughout Green Lake. These cores were analyzed to reconstruct the nutrient history over the past 150 years. Results showed that Green Lake’s western basin had historically slower sedimentation rates than the eastern basin. Recent sedimentation rates within the western basin had increased, however. For all cores, the greatest deposition of nutrients had occurred during the 1990s.

The Annual Nutrient Contribution of Roosting Canada Geese to Green Lake, Wisconsin (1980)

William S. Brooks, et al, Ripon College
Random but frequent visual counts of Canada Geese were made at different times of the day from October to January (14 wk) on Green Lake for 3 seasons (1975-76, 76-77, 77-78), allowing mean hourly numbers to be determined for each day.

Evaluation of Algal Productivity in Green Lake, Wisconsin with Bioassay Techniques (1974)

James Litton et al, Ripon College
As eutrophication of Green Lake was becoming a growing concern, a group of students at Ripon College investigated factors influencing algal blooms. They collected water samples to analyze water quality and to identify algal species. They documented nutrient conditions suggesting nonpoint source pollutants and found a variety of both blue-green and green algae. Algal productivity was also evaluated under differing nutrient environments with results indicating that phosphorous and nitrogen both had stimulatory effects on growth.

Management Plans

A Lake Management Plan for Green Lake (2013, revised 2015)

Mark F. Sesing, et al.
The Green Lake planning team, comprised of eight stakeholder groups in the region, first started work on the Lake Management Plan (LMP) in spring of 2011. The LMP was published in 2013, and this edition was revised in 2015. The LMP brings together new research, previous work, and input from stakeholders and residents in one comprehensive plan which will guide future management efforts for Green Lake. See also Appendices to A Lake Management Plan for Green Lake

Fond du Lac County Land & Water Resource Management Plan (2012)

James D. Kiser, Dale Theel, et al., Fond du Lac County Land Conservation Committee
Fond du Lac County’s Resource Management Plan outlines the county’s goals for the management of soil, water, and other important resources, and defines the actions necessary to achieve these management goals. Many of the goals and steps identified by this document are consistent with the prevailing objectives in the wider Green Lake Watershed, including nutrient management; the prevention of pollution from phosphorus and sediment; the reduction of invasive species populations; and the implementation of BMPs in pursuit of these goals.

Green Lake County Land & Water Resource Management Plan (2011)

Thomas Eddy, Paul Gettelman, et al., Green Lake County Land Conservation Committee
The Land & Water Resource Management Plan was a countywide effort to establish a locally driven process of watershed planning. In 1999, the initial stated goal was to reduce phosphorus and sediment delivery by 35% over 10 years. By 2005, soil erosion had been reduced by 10%. In order to meet further goals, this plan defines a set of objectives and action steps and identifies programs available for landowners and land users to implement conservation practices. The long-term vision is to implement dynamic, effective nonpoint source programs designed to achieve and maintain beneficial uses of water.

The State of the Upper Fox River Basin (2011)

Ellen Barth, Robin McLennan, et al., DNR Natural Resources Board
The Upper Fox River Basin Team and its partners developed a report which identified conditions, issues, and work priorities for the entire basin. The report also identified specific issues for Big Green Lake and its tributaries. Some of the major issues identified by the team included increasing development pressure, inconsistent land management decisions, nonpoint source pollution concerns, aquatic invasive species, and relatively poor understanding of lake hydrology dynamics. The team highlighted the importance of building partnerships within the watershed, establishing goals, and defining strategies to address water resources related problems.

Big Green Lake Priority Watershed Plan Reports (1981-1997)

In 1980, the Green Lake Watershed was one of four watersheds selected in Wisconsin for participation in the Wisconsin Non-point Source Pollution Abatement Program, in large part because of its value as a high water quality recreational resource. The primary role of the project was to provide cost sharing and technical assistance for the control of non-point pollution via installation of best management practices in an effort to reduce sediment and nutrient loading into Green Lake.

Green Lake Priority Watershed Project: Final Report (1997)

Gail Puzach, James Hebbe, Lynn Mathias, Department of Natural Resources

Big Green Lake Priority Watershed Project: Final Evaluation Monitoring Report (1992)

Ron Kroner, Joe Ball, and Mike Miller, Department of Natural Resources

Interim Evaluation of the Big Green Lake Nonpoint Source Control Project (1988)

Jim Bachhuber, Department of Natural Resources

Big Green Lake Priority Watershed Plan (1981)

Richard Quade, Green Lake County Soil and Water Conservation District

Big Green Lake Watershed PL-566 Study (1992)

James Hebbe, Green Lake County Department of Land Conservation
In 1992, the Green Lake Association approached the Green Lake County Land Conservation Department (GLCLCD) to determine the feasibility of implementing a PL-566 project for the Big Green Lake Watershed. The PL-566 program is a federal watershed project where large-scale dams and retention basins are constructed to protect channel areas and to reduce sedimentation from unstable shorelines that would otherwise reach the lake.


Application of the Soil and Water Assessment Tool (SWAT) to Evaluate Non-Point Source Phosphorus and TSS Loads in the Big Green Lake Watershed, Wisconsin

Paul Baumgart, University of Wisconsin-Green Bay
The Soil and Water Assessment Tool (SWAT) is a predictive tool used to estimate potential for phosphorus (P) and total suspended solids (TSS) load reductions in the watershed. The 2015 application of the SWAT estimates average annual loads of 24,000 lbs of P and 2,950 tons of TSS to Green Lake. The SWAT model uses inputs of land cover, land use, tillage practices, nutrient management, soil materials, and stream flows from 1998-2012. This report describes the derivation and structure of the model and the projection results. Wuerches Creek and White Creek had the highest simulated TSS yield. The upper portion of Wuerches Creek had the highest modeled P yield.

Predicting Phosphorus and TSS Export with the Soil and Water Assessment Tool (SWAT) to Evaluate Alternative Agricultural Management Practices in the Big Green Lake Watershed, Wisconsin (2000)

Paul Baumgart, University of Wisconsin-Green Bay
The 2000 application of the Soil and Water Assessment Tool (SWAT) estimates average annual loads of phosphorus (P) and total suspended solids (TSS) to Green Lake and its watershed from 1987-1998. This report compares the predicted annual loads to observed amounts, using the model to estimate potential reductions in P and TSS under alternative management scenarios. The SWAT uses inputs of land cover, land use, tillage practices, nutrient management, climate, and stream characteristics from 1987-1998. This report describes the model’s derivation and the results of the projections. Under current practices, the model estimated annual average loads of 3,707 tons of TSS and 33,820 lbs of P. Wuerches Creek had high yields for P and TSS.

Lake Water Quality Model Study for Big Green Lake, Green Lake Co., Wisconsin (1999)

Stemming from a 1998 DNR lake protection grant, this water quality model of Green Lake examined the impact of watershed pollutants. Monitoring data was used to calibrate a model and to develop a lake loading response curve using the Wisconsin Lake Model Spreadsheet (WILMS) 2.00. The report concluded that based on spring total phosphorus (P) concentrations, the lake was eutrophic. Some criticisms of this conclusion exist, though, because spring data were used in a summer-average model. Silver Creek contributed 44% of the annual total P, which constituted 50% of the tributary loading. The southwest inlet (County K Marsh) was the second largest source of P, contributing 13% of the total and 15% of the tributary input. It was recommended to establish an in-lake total P goal and to develop sufficient BMP’s to meet that goal.

Social Science

Big Green Lake 2012 Citizen Survey Results (2012)

J. McNelly, University of Wisconsin-Stevens Point, UW Extension
In 2012, researchers from the University of Wisconsin-Stevens Point conducted a survey in order to better understand the demographics of the Green Lake watershed. Surveys were sent to 1,000 Green Lake watershed residents, half of whom owned property on Green Lake. A total of 557 residents responded to the survey. The responses revealed several patterns. Most respondents indicated that the lake was of great personal importance. While most respondents were familiar with the Green Lake Association and other local agencies, the responses indicated a lack of knowledge about the lake’s health and a reluctance to adopt best management practices for the health of the lake.


Water Quality Monitoring Report for the Silver Creek Watershed, Green Lake and Fond Du Lac County, Wisconsin (2015)

David Bolha, Wisconsin Department of Natural Resources
This report analyses inorganic chemistry data, aquatic macroinvertebrate (insect) samples, qualitative habitat assessments, and fish surveys at sites on the mainstem of Silver Creek and on its Unnamed Tributaries. Total phosphorus (TP) and Total Suspended Solids (TSS) samples were collected from May-October 2014. Eight out of 11 sampled sites had average TP concentrations that exceeded the water quality criteria of 0.075 mg/L. 10 sites had a “Fair” water quality index based on the macroinvertebrate community, and one site was rated as “Poor”. All sampling sites were assessed to have “Good” habitat conditions. Water quality condition categories based upon fish populations ranged from “Poor” to “Excellent”. Three Unnamed Tributaries of Silver Creek were recommended to be listed as impaired due to degraded habitat with the pollutant TSS, and two were recommended to be listed as impaired due to degraded biological community with the pollutant TP.

Targeted Watershed Assessment Report for Tributaries on the South Side of Big Green Lake, Green Lake County, Wisconsin (2015)

David Bolha, Wisconsin Department of Natural Resources
his assessment used a combination of citizen and DNR water quality monitoring of streams on the south side of Green Lake. Data was collected on total phosphorus (TP), habitat, aquatic macroinvertebrates (insects), and fish. A goal of this assessment was to determine if these streams exceeded state water quality criteria and to establish impairments under the Clean Water Act Section 303d. Stream habitats were quantified as “Good” and “Fair”, and stream bank erosion was identified as a problem. Water quality condition categories based on fish surveys were “Poor” and “Fair”. Water quality condition categories based on the macroinvertebrate community were all rated as “Fair”. Hill Creek was recommended for the Clean Water Act Section 303d Impaired Waters List for degraded biological community due to the pollutant phosphorus.

An Assessment of Hill, Roy, Silver, and Wuerches Creeks (303d Impaired Water) (2011)

Ted Johnson, Adam Nickel, and Eric Evensen, Wisconsin Department of Natural Resources
Impaired waters (as classified under the Clean Water Act Section 303d) were evaluated through fish surveys, macroinvertebrate collection, qualitative habitat assessment, continuous temperature monitoring, and measurements of phosphorus levels. Hill Creek showed categories of Poor for fish and macroinvertebrates. Roy Creek was rated Poor for its fish population. Silver Creek had the highest index for fish populations and rated as Fair, and sampling showed high diversity of macroinvertebrates. Silver Creek had the highest average phosphorus levels of all the creeks sampled. Wuerches had a Poor fish rating and relatively high diversity of macroinvertebrates. All streams in this study showed elevated levels of phosphorus and total suspended solids.

The DNR lists additional documents and grants that show results from volunteer water quality monitoring.

Submit Agency Reports relating to Green Lake’s watershed.