Tomahawk Lake, Upper Tomahawk River Watershed (UW38)
Tomahawk Lake, Upper Tomahawk River Watershed (UW38)
Tomahawk Lake (1542700)
3461.78 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.
Shallow headwater 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.
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.


Tomahawk Lake, in the Upper Tomahawk River Watershed, is a 3,461.71 acre lake that falls in Oneida County. This lake is an outstanding/exceptional resource water under NR102 under the Fisheries Program. This lake is managed for fishing and swimming and is currently not considered impaired.

Date  2011

Author   Aquatic Biologist

Historical Description

Source: 1966, Surface Water Resources of Oneida County Tomahawk Lake, T39N, R7E, Section 31 Surface Acres = 3,626.6, S.D.F. = 3.40, Maximum Depth = 79 feet.

soft water drainage lake having neutral clear water of high transparency. Sand is the predominant littoral material (55 percent) with rubble (20 percent), gravel (19 percent), muck (5 percent) and some boulders. Shoreline is predominantly upland (95 percent) with marsh and bog wetland adjoining limited portions of the lake basin. Fish species found in this lake are muskellunge, northern pike, walleye, largemouth bass, smallmouth bass, perch, bluegill, crappie, rock bass, pumpkinseed, bullhead, cisco andsucker. Lake trout have been introduced with the success of this stocking remaining to be evaluated. Public access with parking is available as well as navigable water access by the outlet stream leading to Minocqua Lake. There are 14 resorts, two public campgrounds, 151 dwellings, three youth camps, four marinas, one private campground and one organizational camp located on the shoreline. Mallard, black duck, blue-winged teal, wood duck and hooded merganser use this lake as a nesting site. Puddle ducks and diving ducks utilize this lake on their fall migrations. Water levels are influenced by a water control structure of four feet head, which is located on the outlet of Kawaguesaga Lake. Part of the Minocqua Chain, water levels are influenced by the dam at the outlet of Kawaguesaga Lake.

Date  1966

Author   Surface Water Inventory Of Wisconsin

Tomahawk Lake, Upper Tomahawk River Watershed (UW38) Fish and Aquatic LifeTomahawk Lake, Upper Tomahawk River Watershed (UW38) RecreationTomahawk Lake, Upper Tomahawk River Watershed (UW38) Fish Consumption

General Condition

Tomahawk Lake (1542700) was assessed during the 2016 listing cycle; total phosphorus and chlorophyll sample data were clearly below 2016 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use. This water is meeting these designated uses and is not considered impaired.

Date  2015

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.



Lakes Planning Grant
Lake Management Plan Development
Social Survey of Residents or Users
Watershed Mapping or Assessment
Aquatic Plant Monitoring or Survey
Map Invasive Species
Develop/Distribute Newsletter
Issue News/Media Release
Lakes Planning Grant
Lake Management Plan Development
Watershed Mapping or Assessment
Water Quality Modeling
Informational Meetings
Monitor Fish Community
Data analysis, report production
Shoreland Monitoring, Assessment, Inventory
Shoreland Monitoring, Assessment or Inventory
ATTAINS Water Identified for Protection
Town of Hazelhurst proposes to develop a comprehensive land use plan and implementation strategies to address the land and water issues in the Town. The Town proposes to work closely with Oneida County's lake classification program to create a land use plan that matches appropriate land uses with the specific class of lakes in the 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

Tomahawk Lake is located in the Upper Tomahawk River watershed which is 186.83 miĀ². Land use in the watershed is primarily forest (67%), wetland (16%) and a mix of open (14%) and other uses (3.10%). This watershed has 139.00 stream miles, 17,609.90 lake acres and 20,470.21 wetland acres.

Nonpoint Source Characteristics

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

Tomahawk Lake is considered a Two-Story 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.

Shallow headwater lake describes the depth and location of the lake in a watershed. These variables affect the lakes response to watershed variables.

Fish Stocking