Lakes & Streams

Big Cedar Lake (Lake) is a 937-acre spring lake located within the Towns of West Bend and Polk in Washington County. As a spring-fed lake, groundwater provides most of the water in the Lake although several small unnamed tributaries provide surface-water inflow, including from 44-acre Gilbert Lake to the northwest. The Lake forms the headwaters of Cedar Creek, which is the Lake’s outlet. Water leaving Big Cedar flows downstream along Cedar Creek into Little Cedar Lake before flowing into the Milwaukee River near Cedarburg and ultimately discharging into Lake Michigan. The Lake is impounded by a weir along its southeastern shore. The Lake attains a maximum depth of 105 feet and a mean depth of 34 feet. Four boat launches provide public access to the Lake: two launches along the western shore on Cedar Park Drive and Gonring Drive and two launches along the eastern shore on Wagner Lane and South Hacker Drive. According to the WDNR Presto-Lite model, the Lake receives runoff from 9.4 square mile watershed; nearly half of the watershed is in agricultural uses while most of the remainder is in forest, urban, and wetland uses. 

The BCLPRD would like to study several issues related to the Lake’s ability to maintain desirable ecological conditions and provide quality recreational opportunities to Lake users. Commission staff used prominent concerns expressed as part of several conversations, meetings, emails, and documents to design a project scope to prepare a comprehensive lake management plan for the Lake. The plan was split into two phases, the first having been completed by Commission staff in 2024. Phase two of the project commenced in spring 2025. 

The major factors proposed to be examined as part of the study are listed below.

• Morphology, hydrology, and watershed conditions
• Lake water quality
• Groundwater
• Shoreline condition
• Septic systems
• Stormwater management
• Pollutant sources and loads
• Aquatic plant community and management
• Recreational use
• Fish and wildlife

Materials prepared for the plan will be posted here as they become available.

Comprehensive Plan Update Presentation

Delavan Lake is a 2,072-acre deep lowland lake located within the Town and City of Delavan in Walworth County. The Lake is popular for its recreational use. The Lake is dammed, and its outflow contributes to Turtle Creek and eventually to the Rock River. Both the Lake and Jackson Creek, the Lake’s primary tributary, are listed on the 303(d) impaired waters list for total phosphorus.

The Commission published a lake management plan for the Lake in 2002. Water quality and pollutant loading remain concerns for the Town of Delavan, the Delavan Lake Sanitary District, the Delavan Lake Improvement Association, and other lake stakeholders. The Town and District requested the Commission’s assistance in updating the comprehensive lake management plan to address issues regarding water quality, pollutant loading, aquatic plants, and recreational use. The draft comprehensive lake management plan is currently in preparation.

Topics addressed in the comprehensive lake management plan include:

• Lake conditions
  • Examine water quality trends
  • Evaluate aquatic plant community
  • Monitor recreational use
• Sediment and phosphorus load reduction
  • Phosphorus and sediment capture by wetland ponds
  • Evaluating best management practice effectiveness
  • Phosphorus and sediment capture by lake inlets
  • Examining efficacy of sediment-consumption pellets
• Lake and watershed management
  • Capacity to and benefits of water level fluctuations
  • Integrate recommendations regarding water quality and pollutant loads
  • Recommend strategies to reduce recreational use conflicts
  • Suggest funding sources and opportunities

Materials prepared for the plan will be posted here as they become available.

Comprehensive Plan Update Presentation

Geneva Lake is one of Wisconsin's largest (5,262 acres) and deepest (140-foot maximum depth) lakes. Located in Walworth County, the Lake is renowned for good water quality and hosts a remarkably diverse array of high-quality recreational opportunities. For its size, Geneva Lake has a very small watershed (less than 30 square miles). 

The Commission completed numerous studies over the past decades providing valuable insight into Lake-related issues, including a 1985 water quality study and 2008 lake management plan.

Geneva Lake stakeholder organizations are currently updating the Lake’s management plan with the Commission’s assistance and with funding through a Wisconsin Department of Natural Resources Surface Water Grant awarded to the Geneva Lake Conservancy. As grantee, the Conservancy is the organization ultimately responsible for executing the grant scope. However, a host of organizations and entities are integral to, and encouraged to participate in, the planning process.

Topics that will be addressed in the Lake Geneva Management Plan include:

• Inventory lake data and management actions
  • Aquatic plant community
  • Water quality
  • Tributary sediment deposition
  • Boat traffic and activity
  • Bigfoot Creek study
  • Past lake management efforts
• Quantify stakeholder perceptions and foster cooperation
  • Conduct lake user survey
  • Stakeholder outreach
  • Enhance stakeholder collaboration
• Inventory watershed condition
  • Delineate and characterize Lake watershed
  • Study select tributaries
  • Windwood Creek demonstration
  • Examine stormwater infrastructure

Materials prepared for the plan will be posted here as they become available.

Water Quality Conditions Presentation

Recreational Use Presentation

Rock Lake is a 45.6-acre deep headwater lake located in the Village of Salem Lakes in Kenosha County. The Lake is a tributary of Trevor Creek, which drains to the Fox River. Attaining a maximum depth of 33 feet, the deepest portions of the Lake are likely not capable of supporting an aquatic plant community, but previous surveys have indicated that the shallow nearshore areas support abundant growth of rooted aquatic plants. The most recent point-intercept survey of the Lake in 2019 by the QI Lake and Pond Solutions observed 24 species. The last plan was completed in 2020 by Lake and Pond Solutions utilizing the 2019 plant data.

The Rock Lake Restoration Association manages aquatic plant growth on Rock Lake to enhance navigation and recreational opportunities through mechanical harvesting and diver-assisted hand-pulling. Aquatic plant management is regulated by the WDNR and requires a permit. Use of chemical treatments requires permit applications annually while mechanical harvesting requires a permit application with accompanying management plan every five years. To apply for an updated permit, the Association has decided to evaluate the Lake’s aquatic plant community and prepare an aquatic plant management plan encompassing the lake. This plan needs to consider the present status of the aquatic plant community, must identify plant community changes that may have occurred, must examine the potential success or lack of success of the current aquatic plant management strategies, must consider current trends and issues that pertain to aquatic plant management issues and techniques, and must describe the methods and procedures associated with proposed continuation of aquatic plant management in the Lake. The Association retained the Commission to conduct an aquatic plant inventory during 2025 and use the information to prepare the aquatic plant management plan by early 2026.

Materials prepared for the plan will be posted here as they become available.

Supporting materials will be posted here as they become available.

The 841-acre Lauderdale Lakes chain spreads over three similarly sized, irregularly shaped, moderately deep natural lakes (Green, Middle, and Mill Lakes) in Walworth County. Although large areas of the Lakes are too deep to support growth of rooted aquatic plants, nearshore areas, bays, and shallow areas support aquatic vegetation. Shallow water areas are most prevalent in Middle and Mill Lake. Much of the western portion of Middle Lake is WDNR-designated Sensitive Area, in which aquatic plant management activity is more restricted. The most recent aquatic survey conducted by the Commission in 2019 observed 17 species in Green Lake, 21 species in Middle Lake, and 19 species in Mill Lake.

The Lauderdale Lakes Lake Management District manages aquatic plant growth on the Lakes to enhance navigation and recreational opportunities. Since 1992, mechanical aquatic plant harvesting has been the primary management strategy employed at the Lakes. Aquatic plant management is regulated by the WDNR and requires the District to periodically evaluate the aquatic plant community, update the aquatic plant management plan to reflect prevailing plant community condition, and renew the aquatic plant management permit every five years. Aquatic plant inventories and management plans have been completed at the Lakes several times in the past to support aquatic plant management permit applications.

In anticipation of permit renewal, the District retained the Commission to complete a new aquatic plant inventory during 2025 and use this information to update its aquatic plant management plan. The updated plan is expected to be published in early 2026. These efforts are supported through a Wisconsin Department of Natural Resources NR 193 Surface Water Grant.

Materials prepared for the plan will be posted here as they become available.

Supporting materials will be posted here as they become available.

Little Muskego Lake is a 481-acre drainage lake located in southeastern Waukesha County within the City of Muskego. Although large areas of the Lakes are too deep to support growth of rooted aquatic plants, nearshore areas, bays, and shallow areas along the eastern and western shores support abundant aquatic vegetation. The Lake has four distinct WDNR-designated Sensitive Areas, in which aquatic plant management activity is more restricted. The most recent aquatic survey of the Lake was conducted in 2023 by WDNR staff during which WDNR observed 17 species in the Lake.

The Little Muskego Lake District manages aquatic plant growth on the Lakes to enhance navigation and recreational opportunities. Since the early 2000s, mechanical aquatic plant harvesting has been the primary management strategy employed at the Lakes; however, chemical treatments and water drawdowns have also been utilized to manage Eurasian watermilfoil and starry stonewort. Aquatic plant management is regulated by the WDNR and requires the District to periodically evaluate the aquatic plant community, update the aquatic plant management plan to reflect prevailing plant community condition, and renew the aquatic plant management permit every five years. Aquatic plant inventories and management plans have been completed at the Lakes several times in the past to support aquatic plant management permit applications. 

The last aquatic plant inventory was completed in September 2023 and the last plan update was completed in June 2019. To renew the permit, the District must evaluate the Lakes’ aquatic plant community and develop an updated aquatic plant management plan. The District retained the Commission to utilize existing aquatic plant inventories to update the aquatic plant management plan. The plan is expected to be published by early 2026. These efforts are supported through a Wisconsin Department of Natural Resources NR 193 Surface Water Grant.

Materials prepared for the plan will be posted here as they become available.

Supporting materials will be posted here as they become available.

Lac La Belle is a 1,164-acre two-story lake located within the City of Oconomowoc and Town of Oconomowoc in Waukesha County. Lac La Belle is the last lake in a chain of six major lakes along the Oconomowoc River system; the River is the primary tributary to and outlet for the Lake. The Lake is quite popular for recreational use and the southern lake shoreline forms the backdrop of the City of Oconomowoc’s downtown.

Lac La Belle was listed on the 2022 303(d) impaired waters list with total phosphorus and polychlorinated biphenyl as pollutants. The Lac La Belle Management District and its partners, particularly the Oconomowoc Watershed Protection Program, are actively implementing projects to address pollutant loading to the Lake. The District has requested the assistance of the Commission in studying phosphorus and water flows to the Lake.

Topics that will be addressed in the study include:

• Monitoring water quality and streamflow on the Lake’s tributaries
• Digitizing the Lake’s bathymetric map
• Updating the Lake-direct watershed delineation
• Developing total phosphorus and water budgets for the Lake
• Prioritizing areas and practices to reduce phosphorus loads

Materials prepared for the plan will be posted here as they become available.

Supporting materials will be posted here as they become available.

The Fox River has its headwaters in southern Washington County and flows largely south for 84 miles to the Wisconsin-Illinois border. Within Wisconsin, Fox River watershed covers 924 square miles across six counties. Plans by the Commission and other entities have addressed water quality, hydrology, water use and supply, and hazard mitigation in the watershed.

The Southeastern Wisconsin Fox River Commission (“SEWFRC”) was established in 1977 by the State of Wisconsin in response to concerns over water resources problems in the Fox River. From 1977 to 2015, SEWFRC had jurisdiction on the Fox River from the City of Waukesha to the Waterford dam. In 2016, SEWFRC expanded its jurisdictional boundary to include an additional 27 miles of the Fox River from Waterford dam to the state line. Due to this expansion, the SEWFRC retained the Commission to:

1. Inventory streambank erosion within the expanded boundary
2. Integrate and compare findings from the expanded area to a prior study conducted within the existing boundary
3. Re-prioritize erosion severity of sites over the entire SEWFRC boundary area
4. Characterize watershed pollutant loading
5. Recommend best management practices and programs to address pollutant loading
6. Publish these findings in a report, which is currently in preparation

The LMPN program was established by WDNR to support networks of organizations conducting essential lake monitoring activities, such as baseline water quality measurements, inspecting watercraft for AIS, purple loosestrife biocontrol, and early detection AIS surveys. Walworth County has received LMPN grant awards each year since 2021. The County has utilized a portion of these grant awards to retain the Commission’s service in monitoring AIS and baseline water quality on lakes within the County. As in previous years, the County has requested that the Commission focus their efforts on County lakes that have less frequent monitoring activities. For the 2025 iteration of the project, the County and Commission agreed to conduct an aquatic plant point-intercept survey on a third lake in addition to the two meander surveys that the Commission has typically conducted.
County and Commission staff reviewed a list of lakes with little recent AIS, aquatic plant, or water quality monitoring activity in publicly available databases. Using this preliminary list, the County decided to conduct an early detection AIS survey on Pell Lake and Lake Como as well as an aquatic plant point-intercept survey on Swift Lake, which has never been surveyed for aquatic plants before. Commission staff will conduct baseline water quality monitoring on all three lakes. 

The data collected from the AIS meander, aquatic plant and water quality surveys will be compiled into a Staff Memorandum report that summarizes key findings. This report is expected to be completed in fall/winter 2025.

Materials prepared for the plan will be posted here as they become available.

Supporting materials will be posted here as they become available.

In 2022, the Wisconsin Department of Natural Resources (WDNR) identified high-quality waters (streams, lakes, and wetlands) across Wisconsin: less than 15% of lakes in Wisconsin were designated as high quality. Additionally, the Commission has identified the most significant remaining natural areas in the Region through its Regional Natural Areas Plan. The goals of these designations are to bring attention and funding to protect high-quality waters, since historically the focus has been on restoring impaired waters.

In 2023, the Commission received four WDNR Surface Water Education Grants. The Commission’s grant projects aim to establish a network of well-informed stakeholders from identified high-quality lakes within Walworth and Waukesha Counties. The Commission will provide a toolkit and a practice-based workshop to inform and train stakeholders on lake data inventory, best management practices, and funding, as well as to form connections and inspire protection of these lakes.

The Commission’s main goals across the grants are to:

• Collect information about WDNR-identified high-quality lakes in Walworth and Waukesha Counties and active stakeholder organizations affiliated with these lakes through discussions and interviews with lake stakeholders.
• Educate stakeholders on how to collect information about lake conditions and management. Facilitate learning and communication between similar lake type network members through a practice-based workshop.
• Publish a best management practice toolkit for each lake type.

Materials prepared for the plan will be posted here as they become available.

Map of HQW in Waukesha & Walworth

Deep Headwater Informational Handout

Deep Lowland Informational Handout

Seepage Informational Handout

Shallow Lowland Reservoir Informational Handout

Two-Story Informational Handout

Interview Questions

2025 National Monitoring Conference Presentation

Healthy Lakes and Rivers

Interviews Project Recap

Lake Chloride Summary

Natural Areas Plan Update

WDNR Surface Water Grants

Wonderful Waters of WI Presentation