Overview

ELKHART LAKE
T16N, R21E, Section 29, 30; MWBIC - 0059300, Sheboygan County, Sheboygan River Watershed
Surface Acres = 300, S.D.F. = 1.83, Maximum Depth = 113 feet

At 300 acres, Elkhart Lake is the largest kettle moraine lake in Sheboygan County and the fourth deepest natural lake in the state. A fair sized, submerged island separates the lake into two major basins. A fixed crested weir at the outlet maintains the water level of the lake. The greatest attraction of the lake is its clear water, which provides excellent swimming, boating, water skiing, and aesthetic enjoyment. Septic tank seepage and isolated surface runoff from adjacent cropland and farm operations has resulted in gradual increases in nutrients in the Lake. These sources could trigger major use problems in the future if control efforts are not expanded.

A two-story fishery exists in Elkhart Lake with the presence of both warmwater and coldwater fish (trout) species. Walleye, panfish, and smallmouth bass, are the mainstays of the fishery. This lake is well known for producing trophy size walleye and northern pike. True muskellunge were introduced in 1987 and are growing at an extremely fast rate due to an abundant forage base. Efforts are underway to increase the amount of fish cover in the lake. In August 1994, Elkhart Lake became the second inland lake in Wisconsin to become infested with zebra mussels. A launch site adjacent to the outlet currently provides public access. Parking is adequate and toilet facilities are provided.

In 1987, the Sheboygan River was selected as a Priority Watershed Project. As a part of this project the land uses and polluted runoff loading to Big Elkhart Lake were inventoried by the Sheboygan County Land Conservation Department. The appraisal report and recommendations for the Big Elkhart Lake area are summarized in the Sheboygan River Priority Watershed Report (WDNR 1993).

A nutrient and water budget sponsored by the Elkhart Lake Improvement Association, and moneys obtained from the DNR through the Wisconsin Lake Management Planning Grant Program, has been completed for the lake by the University of Wisconsin-Milwaukee and the U.S. Geological Survey (Edgington et al. 1996). It is recommended that a detailed fishery survey be conducted to determine the community structure of the fishery. This is recommended since the existing zebra mussel study is not going to be evaluating this portion of the food chain and additional information on the fish community structure on Big Elkhart Lake would augment that study. It is also recommended that the general water quality condition of the lake be evaluated on a recurring basis. Water use objectives are also found in the Nonpoint Source Control Plan for the Sheboygan River Priority Watershed Project, (WDNR 1993). The water resource objectives for this lake need to be reevaluated in light of the modeling results that are being completed by the Center for Great Lake Studies and the discovery of the zebra mussel in the lake. These two elements will guide and influence the future of Big Elkhart Lake.

Aquatic Plants

The aquatic plant community in Big Elkhart Lake can best be described as sparse. In addition to the field survey conducted in 1994 aerial photographs of the lake were taken in 1993 to assist in the development of a Eurasian Water milfoil (EWM) control program for the Big Elkhart Lake Property Owners Association. The photographs from the aerial survey are archived in the Big Elkhart Lake file in the Southeast District headquarters, a duplicate set was given to the Proper Owners Association.

Date  2001

Author   Aquatic Biologist

Overview

Eurasian Water milfoil was present in approximately 15 locations around the lake in 1993. There were 3 areas with EWM in 1994. There appeared to be a significant decrease in the overall plant growth in Big Elkhart Lake in 1994 compared to 1993, which was substantiated by conversations with local residents. Table 43 lists the species present during the general survey.

Table 33. Aquatic plants in Big Elkhart Lake Sheboygan Co., 1994.
Common Name Scientific Name
Musk Grass
Pondweed
Richardson Pondweed
Bulrush
Sago Pondweed

Eurasian Watermilfoil
Coontail
White Water Lily Chara sp.
Potamogeton sp.
Potamogeton richardsonii
Eleocharis sp.
Potamogeton pectinatus

Myriophyllym spicatum
Ceratophyllum demersum
Nymphaea sp.

Water Quality

The water quality of Big Elkhart Lake was monitored once in May and again in September during 1994. Temperature and dissolved oxygen profiles were made in the northern basin in May and the southern basin in September. The temperature in September shows a normal thermal profile with a 16-degree stratification factor. The dissolved oxygen profile can be characterized as a typical clinograde profile except it has a dissolved oxygen peak in the metalimnion. This dissolved oxygen peak is very strong and has been documented during other limnological surveys of the lake. The dissolved oxygen in the metalimnion has been measured to be greater than 20 ppm during earlier surveys. The lake is well stratified by September with a thermocline at a depth of approximately 35 feet. The hypolimnion was anoxic at a depth of 60 feet, and there was greater than 5 ppm dissolved oxygen to a depth of 45 feet (Wakeman 1996).

During water quality surveys conducted in 1994, the pH, specific conductance and total dissolved solids were 8.4 su, 470 (mS/cm), and 0.201 (g/l) respectively, at the surface in September. At the thermocline the same parameters were 8.1 su, 495 (mS/cm), and 0.317 (g/l) respectively. At 115 feet, the pH was 7.2 su, specific conductance was 549 (mS/cm) and total dissolved solids were 0.351 (g/l).

Trophic Status Index

The trophic status index for Big Elkhart Lake indicates a seasonally variable trend. Within one year the trophic status can go from Eu-Mesotrophic to Meso-Oligotrophic as indicated in Figure 13. The spatial distribution of primary producers in the lake results in an underestimation of productivity by conventional trophic status indices. It is believed that the spring Trophic Status Index is an accurate measure at that time however the summer values significantly underestimate the productivity of the lake.

Date  2001

Author   Aquatic Biologist

Historical Description

Source: 1968, Surface Water Resources of Sheboygan County

(Big) Elkhart Lake T16N, R21E, Section 29, 30
Surface Acres = 300, S.D.F. = 1.83, Maximum Depth = 113 feet
The largest, kettle moraine lake in the county, fourth deepest lake
in the state. A fair sized, submerged island separates the lake into two
major basins. The greatest attraction of the lake is its clear waters,
which provides excellent swimming, boating, water-skiing, and esthetic
enjoyment. Gradual increases in fertility entering the lake in the form
of septic tank seepage, and some isolated surface runoff from adjacent
cropland and farm operations, could trigger major use problems in the
future, if control efforts are not expanded. The presence of 4 resorts,
132 dwellings, and 1 public boat access site with parking, and two
beaches, confirms the lake's attributes. Walleyes, panfish, and
smallmouth bass, are the mainstay of the fishery. Splake were
experimentally planted in 1965 and 1967 to help diversify the fishery.

Date  1968

Author   Surface Water Inventory Of Wisconsin

Impaired Waters

Elkhart Lake (59300) was placed on the impaired waters list for Mercury in fish tissue in 1998. This water was assessed during the 2016 listing cycle; total phosphorus and chlorophyll sample data were clearly below 2016 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use. This lake is considered impaired for Fish Consumption use and meeting REC and FAL uses.

Date  2015

Author  Aaron Larson

Condition

Wisconsin has over 84,000 miles of streams, 15,000 lakes and milllions of acres of wetlands. Assessing the condition of this vast amount of water is challenging. The state's water monitoring program uses a media-based, cross-program approach to analyze water condition. An updated monitoring strategy (2015-2020) is now available. Compliance with Clean Water Act fishable, swimmable standards are located in the Executive Summary of Water Condition in 2018. See also the 'monitoring and projects' tab.

Reports

Management Goals

Wisconsin's Water Quality Standards provide qualitative and quantitative goals for waters that are protective of Fishable, Swimmable conditions [Learn more]. Waters that do not meet water quality standards are considered impaired and restoration actions are planned and carried out until the water is once again fishable and swimmable

Management goals can include creation or implementation of a Total Maximum Daily Load analysis, a Nine Key Element Plan, or other restoration work, education and outreach and more. If specific recommendations exist for this water, they will be displayed below online.

Monitoring

Monitoring the condition of a river, stream, or lake includes gathering physical, chemical, biological, and habitat data. Comprehensive studies often gather all these parameters in great detail, while lighter assessment events will involve sampling physical, chemical and biological data such as macroinvertebrates. Aquatic macroinvertebrates and fish communities integrate watershed or catchment condition, providing great insight into overall ecosystem health. Chemical and habitat parameters tell researchers more about human induced problems including contaminated runoff, point source dischargers, or habitat issues that foster or limit the potential of aquatic communities to thrive in a given area. Wisconsin's Water Monitoring Strategy was recenty updated.

Grants and Management Projects

Monitoring Projects

Watershed Characteristics

Elkhart Lake is located in the Sheboygan River watershed which is 260.12 mi². Land use in the watershed is primarily agricultural (47.30%), grassland (17.60%) and a mix of wetland (16.70%) and other uses (18.30%). This watershed has 340.24 stream miles, 4,345.33 lake acres and 27,968.05 wetland acres.

Nonpoint Source Characteristics

This watershed is ranked Not Available for runoff impacts on streams, Not Available for runoff impacts on lakes and High for runoff impacts on groundwater and therefore has an overall rank of High. This value can be used in ranking the watershed or individual waterbodies for grant funding under state and county programs.However, all waters are affected by diffuse pollutant sources regardless of initial water quality. Applications for specific runoff projects under state or county grant programs may be pursued. For more information, go to surface water program grants.