Petenwell Flowage, Wisconsin Rapids,Fourteenmile Creek,Big Roche A Cri Creek,Lower Yellow (Juneau Co.) River Watershed (CW02)
Petenwell Flowage, Wisconsin Rapids,Fourteenmile Creek,Big Roche A Cri Creek,Lower Yellow (Juneau Co.) River Watershed (CW02)
Petenwell Flowage (1377100)
23000.81 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.
This impoundment is impaired
High Phosphorus Levels, Mercury Contaminated Fish Tissue, Dioxin Contaminated Fish Tissue, Low DO, PCBs Contaminated Fish Tissue, PFOS Contaminated Fish Tissue
Mercury, Dioxin, PFOS, Total Phosphorus, PCBs
Adams, Juneau
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.
Shallow Lowland
Shallow lowland lake describes the depth and location of the lake in a watershed. 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.
Streams capable of supporting a warm waterdependent sport fishery. Representative aquatic life communities associated with these waters generally require cool or warm temperatures and concentrations of dissolved oxygen that do not drop below 5 mg/L.
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.
Streams capable of supporting a cold water sport fishery, or serving as a spawning area for salmonids and other cold water fish species. Representative aquatic life communities, associated with these waters, generally require cold temperatures and concentrations of dissolved oxygen that remain above 6 mg/L. Since these waters are capable of supporting natural reproduction, a minimum dissolved oxygen concentration of 7 mg/L is required during times of active spawning and support of early life stages of newly-hatched fish.


Petenwell Lake is a soft water, drainage impoundment on the Wisconsin River that is the second largest lake within the State. Its water level is controlled by a hydroelectric power dam having a 42-foot head and it is owned by the Wisconsin River Power Company. The water has a light brown color, is alkaline, and has a low transparency. Northern pike, walleye, largemouth bass, bluegill, pumpkinseed, crappie, perch, and bullhead are the significant game fish species present. Commercial fishing for rough fish species and bullhead has taken place. Industrial pollution is a problem. Partial winterkill conditions exist. Public parks (multiple-use areas) are present in Adams and Juneau Counties. Commercial facilities are available and a few dwellings are present. Several species of puddle ducks nest at the flowage and there is also a heron rookery. Canada geese, coot, puddle ducks and divers use the area during their spring and fall migrations. Beaver are present and muskrat are significant.

Source: 1969, Surface Water Resources of Juneau County Petenwell Flowage, T18N, R4E, Section 4 Surface Acres = 22,218, S.D.F. = 3.88, Maximum Depth = 44 feet

Date  1969

Author   Aquatic Biologist

Historical Description

Jim Kreitlow (NOR) documented dissolved oxygen standards violations while sampling the lake in the mid 1990s. Dissolved oxygen concentrations below 5 mg/l were generally found during the early morning hours, probably a result of algae respiration. Values for pH above 9.0 were documented in 1996, 1997 and 1998.

The cause of these impairments is likely the result of excessive nutrient loading (phosphorus) from point and nonpoint sources in the watershed. As a result, the flowage is very eutrophic with abundant algae growth. The University of Wisconsin Stevens Point completed a nutrient and water budget modeling study in 1999 on Petenwell Flowage. Water chemistry data collected in 1996 indicates chlorophyll a concentrations ranged from 8.4 to 66.6 ug/l and total phosphorus concentrations ranged from 85 to 171 ug/l.

The Petenwell and Castle Rock Flowages Comprehensive Management Plan was completed in 1996. The report indicates severe algal blooms cause periodic shifts in dissolved oxygen. During photosynthesis, dissolved oxygen values are high (11-12 mg/l) but during respiration, they can drop below 5.0 mg/l (STORET 1992 was referenced). The report also indicates blue-green algae are the dominant phytoplankton in the Petenwell and Castle Rock Flowages. The report also references sediment sampling has been completed in both flowages however additional sampling is recommended. Previous sampling has found high levels of 2,3,7,8-TCDD and 2,3,7,8-TCDF in sediments. PCBs and mercury have also been detected at limited sampling sites. Currently, a fish consumption advisory exists on the flowage for PCBs, dioxin and mercury.

Monitoring conducted in 2003 found frequent pH exceedances during the summer.

Date  2006

Author   Aquatic Biologist

Petenwell Flowage, Wisconsin Rapids,Fourteenmile Creek,Big Roche A Cri Creek,Lower Yellow (Juneau Co.) River Watershed (CW02) Fish and Aquatic LifePetenwell Flowage, Wisconsin Rapids,Fourteenmile Creek,Big Roche A Cri Creek,Lower Yellow (Juneau Co.) River Watershed (CW02) RecreationPetenwell Flowage, Wisconsin Rapids,Fourteenmile Creek,Big Roche A Cri Creek,Lower Yellow (Juneau Co.) River Watershed (CW02) Fish Consumption

Impaired Waters

Petenwell (Flowage) Lake has been on the state's 303(d) impaired waters list since 1998 for Total Phosphorus (TP), Dioxin, PCBs, and Mercury. This lake was placed under a special fish consumption advisory for PFOS in 2020; this lake had a listing of PFOS in fish tissue placed on the 2022 Impaired Waters List.

Date  2022

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.



Educate and engage residents
Adams County proposes to provide educational and technical assistance to the public and Adams County lake organizations for the installation of shoreline buffers on waterways so they comply with the Adams County Shoreland, Wetland, and Habitat Protection Ordinance.
Habitat Restoration - Shoreland
Water Quality Modeling
Adams County proposes to provide up to 75% of the cost of shoreland restoration practices to lake front property owners on the Petenwell Flowage. Grant funds will be distributed to fund removal of sea walls, minor bank re-shaping, placement of rip-rap, establishment of vegetative buffers and implementation if individual stormwater management plans.
Lake Classification
Adams County proposes to wrap up its county-wide lake classification effort. Major project elements to include: 1) completion of water sampling, 2) development of lakes classification report and individual lake summaries, 3) development of a powerpoint presentation, 4) four public meetings, 5) expansion of shoreline restoration packet.
Lake Classification
Adams County continue its lake classification efforts through collecting and assessing chemical and biological data on all lakes within the county that afford public access. Major project componants to include: 1) collection and assessment of chemical and biological data, 2) development of a "library" of information for public use, 3) development of management recommendations, 4) I&E for riparians and lake users.
Lake Classification
Adams County proposes to initiate a Lakes Classification effort to assist in comprehensive plan development for communities surrounding its lakes with public access. Phase 1 elements, to be funded with this grant, include: 1) delination of surface watersheds and flow patterns, 2) delineation of ground watersheds, 3) identification and mapping of land uses, 4) inventory and mapping of shoreline erosion and development problems, 5) identification and mapping of sensitive/critical areas and natural heritage habitats, 6) verification of wetland delineations, 7) delineations of lake watersheds, 8) development of lake maps
Water Quality Modeling
Golden Sands Resource Conservation and Development Council, Inc. proposes to complete the second year of funding for water quality modeling of the Petenwell Flowage. Implementation of this plan will provide information on the following: 1) water/nutrient budget for the Petenwell Flowage, 2) sources of nutrients, 3) effects of nutrient reduction, and 4) prediction of the total maximum daily loads necessary to reach desired target nutrient levels. A working Model will be provided as well as a final report will be available for interested parties.

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

Petenwell Lake is located in the Lower Yellow (Juneau Co.) River watershed which is 261.05 miĀ². Land use in the watershed is primarily forest (43.70%), wetland (43.70%) and a mix of open (6.60%) and other uses (6.00%). This watershed has stream miles, lake acres and 65,343.09 wetland acres.

Nonpoint Source Characteristics

This watershed is ranked Low for runoff impacts on streams, Low for runoff impacts on lakes and Low for runoff impacts on groundwater and therefore has an overall rank of Low. 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

Petenwell Flowage is considered a Reservoir 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.