Mukwonago River, Mukwonago River Watershed (FX06)
Mukwonago River, Mukwonago River Watershed (FX06)
Mukwonago River (765500)
2.35 Miles
0 - 2.35
Natural Community
Natural communities (stream and lake natural communities) represent model results that use predicted flow and temperature based on landscape features and related assumptions. Ranges of flow and temperature associated with specific aquatic life communities (fish, macroinvertebrates) help biologists identify appropriate resource management goals. Wisconsin Natural Communities.
Warm Mainstem
Year Last Monitored
This is the most recent date of monitoring data stored in SWIMS. Additional surveys for fish and habitat may be available subsequent to this date.
Trout Water 
Trout Waters are represented by Class I, Class II or Class III waters. These classes have specific ecological characteristics and management actions associated with them. For more information regarding Trout Classifications, see the Fisheries Trout Class Webpages.
Outstanding or Exceptional 
Wisconsin has designated many of the state's highest quality waters as Outstanding Resource Waters (ORWs) or Exceptional Resource Waters (ERWs). Waters designated as ORW or ERW are surface waters which provide outstanding recreational opportunities, support valuable fisheries and wildlife habitat, have good water quality, and are not significantly impacted by human activities. ORW and ERW status identifies waters that the State of Wisconsin has determined warrant additional protection from the effects of pollution. These designations are intended to meet federal Clean Water Act obligations requiring Wisconsin to adopt an 'antidegradation' policy that is designed to prevent any lowering of water quality - especially in those waters having significant ecological or cultural value.
Impaired Water 
A water is polluted or 'impaired' if it does not support full use by humans, wildlife, fish and other aquatic life and it is shown that one or more of the pollutant criteria are not met.

Fish and Aquatic Life

Current Use
The use the water currently supports. This is not a designation or classification; it is based on the current condition of the water. Information in this column is not designed for, and should not be used for, regulatory purposes.
Fish and Aquatic Life - waters that do not have a specific use designation subcategory assigned but which are considered fishable, swimmable waters.
Attainable Use
The use that the investigator believes the water could achieve through managing "controllable" sources. Beaver dams, hydroelectric dams, low gradient streams, and naturally occurring low flows are generally not considered controllable. The attainable use may be the same as the current use or it may be higher.
Fish and Aquatic Life - waters that do not have a specific use designation subcategory assigned but which are considered fishable, swimmable waters.
Designated Use
This is the water classification legally recognized by NR102 and NR104, Wis. Adm. Code. The classification determines water quality criteria and effluent limits. Waters obtain designated uses through classification procedures.
Default FAL
Fish and Aquatic Life - Default Waters do not have a specific use designation subcategory but are considered fishable, swimmable waters.


The Mukwonago River is a 16.8-mile-long river in Walworth and Waukesha Counties. Mile 4.08 through 9.68 (from the mouth) is classified as a Class II trout water. Mile 9.68 through 9.76 of Mukwonago River is classified as a Class III trout water, and Mile 11.97 through 15.47 of the river is a Class I trout water.

Date  2012

Author   Aquatic Biologist

Mukwonago River, Mukwonago River Watershed (FX06) Fish and Aquatic LifeMukwonago River, Mukwonago River Watershed (FX06) RecreationMukwonago River, Mukwonago River Watershed (FX06) Fish Consumption

General Condition

Mukwonago River was assessed during the 2018 listing cycle; new chloride and new biological (macroinvertebrate and fish Index of Biotic Integrity (IBI) scores) sample data were clearly below the 2018 WisCALM listing thresholds for the Fish and Aquatic Life use. This water was meeting this designated use and was not considered impaired.

Date  2017

Author  Ashley Beranek


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.



Monitor Water Quality or Sediment
Conduct water quality sampling on the Mukwonago River
Information and Education
Nature Conservancy interns in canoes will also intercept boaters utilizing the channel between Lulu and Eagle Springs and speak about reversing their motors to prevent the spread of exotic species
Control Invasive Species
Worked to control Phragmites, purple loosestrife, reed canary grass, buckthorn, Eurasian water milfoil and narrow leafed cattail. Control methods include hand pulling, hand cutting, backpack chemical treatment and beetle rearing/dispersal.
Monitor Water Quality or Sediment
More data collect, continuous monitoring, biology not showing impairment. AU: 897059; ID: 10029281
Nutrient Budget Development
Data analysis, report production
Evaluated data and literature regarding potential impacts of swimming on the water quality of lakes
Educate and engage residents
The Friend's of the Mukwonago River group proposes to hire part-time staff and institute a volunteer program. This project will support efforts to implement Phase 2 of their organizational capacity building plan. Goals and objectives will include: - Implement sustainable financial and organizational development practices - Institute youth camp watershed service learning program - Build comprehensive membership and volunteer program - Activate, educate, and engage general population and targeted organizations, business, and riparian populations in villages, towns, and counties The project area includes the entire Mukwonago River watershed. A final project report will be submitted to the WDNR.
Partnership Project
Enhance both internal and external measures of organizational effectiveness. This project would include: 1) Hire staff to enhance internal support and establish external partnerships and public outreach and membership building. Develop a strategic plan. 2) Increase public exposure to information on the Mukwonago and its watershed via website, publications and presentation while crafting a priority action plan for fundraising, organizational growth, educational outreach and further accomplishment of mission objectives. 3) Develop website, publications, new or enhanced partnerships, an event to highlight the Mukwonago River, and produce a project summary. A final report incorporating all of the project deliverable will be provided.
Drawdown of Water
1) Successfully drawdown two impoundments on the upper Mukwonago river followed by removal of the two dams with negative impact down stream. 2) Permanently mitigate the risk of either dam breaching causing negative impacts down stream. 3) Restore the functional wetland system to the areas of the current impoundments by recreating approximately 15 acres of wetland. 4) Repair several areas around the two impoundments that have been altered by the fisheries operation to return features to historic conditions.
Lakes Protection Grant
This is part of a multi phased program to gather information, assess, response and determine how best to coordinate and cooperate on projects with Phantom Lakes Management District, Lake Beulah , Eagle Springs Management Districts, The Nature Conservancy and Friends of the Mukwonago River. This project will also result in a stream protection plan, data, information and analyses of the upper reaches of the Mukwonago River. All of the data and information collected will included in a single comprehensive river protection plan. The results will also be communicated to the citizens through I&E programs of the Friends of the Mukwonago River, The Nature Conservancy and governmental meetings.
Protect Riparian or Shorelands
Develop a management and protection plan to enhance the water quality and biological integrity of the stream and its riparian corridor. A full description of the project scope and deliverables is available in the grant application, which is part of this agreement. The DNR will be provided with two paper copies and an electronic copy of the final report. Information will be disseminated to the public as described in the grant application.
Rivers Planning Grant
The Eagle Spring Lake Mgt. Dist. is applying for a river planning grant to help fund a water quality monitoring study on tributaries of the Mukwonago River. The purpose of the project is to determine nutrient loading problems to the streams and use the data to work with local government on land use and development issues. Two local organizations (Mukwonago River Initiative and Friends of Mukwonago River) would also like to utilize the project to gain membership and financial support for future projects. Ten water samples will be collected five times per year for 2004-2006. Lab analysis with be done by UWSP and will include conductivity, total and reactive phosphorus, ammonia, nitrate-nitrite nitrogen, total kjeldahl nitrogen, chloride, and total solids. Lab costs total $9639.00. Total project costs are $12,308.00. Therefore, sponsor match is about $3100.00 to be shared by Eagle Spring and Phantom Lakes Mgt. Dist. Mukwonago River is an ERW and these tributaries are vital to its protection. The district intends to uitilize press release, newsletters, mailings, and public presentations for I&E Effors. Area School groups willl be involved in sampling and data evaluation. A Final report will be submitted to the WDNR at the end of the project period.
Rivers Planning Grant
The Waukesha Land Conservancy proposes to develop a video of the Mukwonago River to be used for educational programs on the river protection efforts and recruitment of new members.
Information and Education
The Waukesha Land Conservancy proposes to develop a video of the Mukwonago River to be used for educational programs on the river protection efforts and recruitment of new members.
Engage Volunteers in Monitoring/Restoration
The Waukesha Land Conservancy proposes to develop a video of the Mukwonago River to be used for educational programs on the river protection efforts and recruitment of new members.
Water Quality Planning
Water Quality Planning
Aquatic resources, including fish and aquatic plants, in the Mukwonago River Watershed should be monitored and managed in consideration of existing and revised plans. Evaluation of the plans over time should be done to review and revise the success of the activities and available resources.
Stormwater Planning, Implementation
Consider the many unique and threatened / endangered resources in the Mukwonago River Watershed when planning and implementing stormwater controls.
Information and Education
Coordinate outreach efforts to improve awareness of the valuable resources in the Mukwonago River Watershed.
Stormwater Planning, Implementation
Coordinate planning and implementation of construction and long-term stormwater management controls in the Mukwonago River Watershed among local, county and state authorities, including state transportation projects.
Protect Riparian or Shorelands
Plan developments with consideration for protection and / or enhancement of natural resources and habitat areas that define the unique character of the Mukwonago River Watershed.

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 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

Mukwonago River is located in the Mukwonago River watershed which is 86.21 miĀ². Land use in the watershed is primarily forest (28.40%), agricultural (22.80%) and a mix of suburban (16.90%) and other uses (31.90%). This watershed has 63.38 stream miles, 2,340.41 lake acres and 4,822.44 wetland acres.

Nonpoint Source Characteristics

This watershed is ranked Medium for runoff impacts on streams, High 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.

Natural Community

Mukwonago River is considered a Warm Mainstem under the state's Natural Community Determinations.

Natural communities (stream and lake natural communities) represent model resultsand DNR staff valiation processes that confirm or update predicted conditions based on flow and temperature modeling from historic and current landscape features and related variables. Predicated flow and temperatures for waters are associated predicated fish assemblages (communities). Biologists evaluate the model results against current survey data to determine if the modeled results are corect and whether biological indicators show water quaity degradation. This analysis is a core component of the state's resource management framework. Wisconsin's Riverine Natural Communities.

Warm Mainstem waters are moderate-to-large but still wadeable perennial streams with relatively warm summer temperatures. Coldwater fishes are absent, transitional fishes are common to uncommon, and warm water fishes are abundant to common. Headwater species are common to absent, mainstem species are abundant to common, and river species are common to absent.