Stoughton Millpond, Yahara River and Lake Kegonsa Watershed (LR06)
Stoughton Millpond, Yahara River and Lake Kegonsa Watershed (LR06)
Stoughton Millpond (802000)
9.92 Acres
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.
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.
Small lake describes the size of small isolated waters. These variables affect the lakes response to watershed variables.
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.
Aquatic Life
Waters that support fish and aquatic life communities (healthy biological communities).
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.


Rock River Water Quality Management Plan, Lower Rock River Appendix. WT-668-2002. South Central Region, WDNR.

The Stoughton Millpond is a shallow impoundment of the Yahara River. It has a surface area of 82 acres and a maximum depth of 5 feet. The majority of the millpond lies within the Stoughton city limits. The surrounding land is dominated by agriculture to the north and municipal and residential areas to the south. Non-point source pollution and urban stormwater runoff negatively impair the millpond. No major wetlands border the lake, but several small sedge and grass meadows provide limited habitat for waterfowl and muskrats. The lake bottom is mostly clay with sand, silt, and some detritus present as well. With the exception of cattail stands on the lake’s east side, macrophytes are scarce as a result of the large carp population. The water is turbid, alkaline, and shows signs of eutrophication. Nuisance algae growths are common.
The Stoughton Millpond supports a diverse warm water fishery, and fish species include northern pike, common carp, bluntnose minnow, buffalo (unsp.), white sucker, black, yellow and brown bullhead, brook silverside, green sunfish, pumpkinseed, bluegill, largemouth bass, white and black crappie, johnny darter, yellow perch, walleye, and freshwater drum. Access is available at Stoughton and from the Yahara River by way of Viking County Park just north of the lake.

The Stoughton Dam is located in the City of Stoughton, which owns and operates it. Built in 1843, the spillway was washed out following a large storm in 1915 that also caused the Dunkirk and Stebbinsville dams to fail and was re-built the following year. The Stoughton dam generated power until the summer of 1999. The City of Stoughton would need to apply for a federal license if they elect to generate electricity again.
The dam is 520 feet long and 14.3 feet high with a normal hydraulic height (difference between headwater and tailwater) of 9 feet and dam creates a long, narrow impoundment lined with many landowners. The maximum storage capacity is 108 acre-feet, which can handle a flood of 2-1/2 times the magnitude of the 100-year flood. The dam must pass 15 cubic feet of water per second, which is the seven-day low flow with a ten-year recurrence interval on the Yahara River. The maximum water level is 842 feet and the minimum is 841 feet. The dam appears to need of only minor repairs but has not been inspected recently.

Date  2002

Author   Aquatic Biologist

Stoughton Millpond, Yahara River and Lake Kegonsa Watershed (LR06) Fish and Aquatic LifeStoughton Millpond, Yahara River and Lake Kegonsa Watershed (LR06) RecreationStoughton Millpond, Yahara River and Lake Kegonsa Watershed (LR06) Fish Consumption


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.


Lake Classification
Dane County Lake Classification-Phase 2: The Phase 1 classification grant classified all county lakes and streams. This grant will take the next step by developing a management program based on the classification.
Lake Classification
Dane County Department of Planning and Development will hire a project staff in order to develop a Lake Classification project, which is seen as the first step toward developing a consistent set of county-wide standards and procedures to protect Dane County Waters.
Rivers Management Grant
Stoughton is proposing to improve its river environment, promote recreational and business activities on and along the river, and improve the communities' understanding of the economic value of the Yahara River. The primary goals and objectives of the river planning project will be to define demographic characteristics of the public users of the City's waterfront areas and ecologically sensitive improvements to these areas that promote use and also provide economic advantages for the City and its waterfront businesses. Another goal is to create a coordinated approach to protecting the river using existing river organizations.
Sewer Service Area Planning
The City of Stoughton is requesting amendment to the Stoughton USA. The area is located at the northwestern corner of the City, abutting Town of Dunn, Town of Dunkirk, and Town of Rutland. The majority of the area is currently within the City. Three town islands currently exist in the amendment area: a roughly 1.5-acre parcel in the Town of Rutland and two parcels totaling around 14 acres in the Town of Dunkirk. The amendment area is split in half by USH 51. Existing land use is primarily agriculture, woodlands, other open lands, and single-family. Proposed land use to the east of USH 51 includes large-scale multi-family and duplex residential, open space/park, and stormwater management. Proposed uses immediately west of USH 51 include commercial and stormwater management, while large and small-scale multi-family residential, single-family residential, open space/park, and stormwater management uses are proposed further west.

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

Stoughton Millpond 429 is located in the Yahara River and Lake Kegonsa watershed which is 126.33 miĀ². Land use in the watershed is primarily agricultural (54.90%), grassland (10.70%) and a mix of wetland (10.30%) and other uses (24.20%). This watershed has 145.73 stream miles, 3,600.04 lake acres and 6,832.19 wetland acres.

Nonpoint Source Characteristics

This watershed is ranked Medium for runoff impacts on streams, Low 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

Stoughton Millpond is considered a Small under the state's Natural Community Determinations.

Natural communities (stream and lake natural communities) represent model results and 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.

Small lake describes the size of small isolated waters. These variables affect the lakes response to watershed variables.