Couderay River, Couderay River,Weirgor Creek and Brunet River Watershed (UC19)
Couderay River, Couderay River,Weirgor Creek and Brunet River Watershed (UC19)
Couderay River (2384700)
1.83 Miles
0 - 1.83
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.
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.
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.
Default FAL
Fish and Aquatic Life - Default Waters do not have a specific use designation subcategory but are considered fishable, swimmable waters.


The Couderay River joins the Chippewa River just below the Arpin Dam: upstream of this
confluence, the Couderay is impounded to form the Grimh Flowage.

Larson, Nancy and Lisa Kosmond (Helmuth). 1996. Upper Chippewa River Basin Water Quality Management Plan.
PUBL-WR-345-96-REV. Wisconsin Department of Natural Resources, Madison, WI.

Date  1996

Author   Aquatic Biologist


The Couderay River is fed by Grindstone, Lac Courte Oreilles, Whitefish, and Sand lakes
in west-central Sawyer County. From its outlet at Little Lac Courte Oreilles, the
Couderay flows south 5.5 miles, before heading east to meet the Chippewa River just
below Radisson. There are two impoundments on the river, the Billy Boy Flowage, a 74-
acre impoundment just south of Little Lac Courte Oreilles, and Grimh Flowage, an 86-
acre impoundment near Radisson which has a hydroelectric plant. Fish movement
between the Chippewa and Couderay Rivers is blocked by dams. The Couderay would
probably be a sturgeon stream if not for the barrier imposed by the dam at Grimh
The Couderay River, which is managed as a sports fishery, is better known for its
rougfish than its northern pike and walleye (Pratt 1993). The river is one of the few
streams in the watershed not known to be affected by beaver activity.

Date  1996

Author   Aquatic Biologist

Couderay River, Couderay River,Weirgor Creek and Brunet River Watershed (UC19) Fish and Aquatic LifeCouderay River, Couderay River,Weirgor Creek and Brunet River Watershed (UC19) RecreationCouderay River, Couderay River,Weirgor Creek and Brunet River Watershed (UC19) 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.



Shoreland Monitoring, Assessment, Inventory
Courte Oreilles Lake Association is sponsoring a project to design and install shoreline buffer restorations on Lac Courte Oreilles and Little Lac Courte Oreilles Lakes. Project tasks include: 1) Shoreline buffer design/restoration on approximately 25 shoreline sites; 2) Modeling to estimate TSS and TP reductions from buffer restorations; 3) Develop and distribute shoreline buffer educational materials.

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

Couderay River is located in the Weirgor Creek and Brunet River watershed which is 324.00 miĀ². Land use in the watershed is primarily forest (64.80%), wetland (24.80%) and a mix of agricultural (4.10%) and other uses (6.40%). This watershed has 407.41 stream miles, 2,240.99 lake acres and 39,377.08 wetland acres.

Nonpoint Source Characteristics

This watershed is ranked Low for runoff impacts on streams, Not Ranked 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

Couderay 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.

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