Fish and Aquatic Life
Grand Portage Lake is a medium hard water drainage lake having alkaline, clear water of moderate transparency. There are two inlet streams, one from Little Martha Lake, which affords little or no boating use, and one from Martha Lake, which is navigable to small craft. The outlet stream to Mercer Lake is navigable to small craft, however, there is an obstruction at the second downstream bridge due to a municipal water and sewer pipe that obstructs floating craft. Grand Portage Lake is part of the Little Turtle River drainage. Sand is the predominant littoral material (90 percent), with muck (5 percent), gravel (3 percent) and same rubble and boulders. The shoreline is predominantly upland (93 percent), 40 percent of which is cleared, with the remaining shoreline being wetland of the bog type. The common game fish are walleye and largemouth bass but some muskellunge and northern pike are present. Panfish include perch, bluegill, black crappie, rock bass and pumpkinseed. Black bullhead, white sucker and redhorse sucker complete the list. Waterfowl use by puddle ducks, diving ducks and on occasion Canada geese does occur but is somewhat limited. Mallard and black duck utilize this lake as a nesting site. Floating, emergent and submergent vegetation is moderate in density in half of the littoral area. There are 25 dwellings and three resorts located on the shoreline. There is a public swimming beach and recreational area on the north shore. Public access with parking from an improved landing is available from a town facility. There is 0.1 mile of public frontage owned by the Town of Mercer.
Surface Acres = 143.8, s.D.F. = 1.85, Maximum Depth = 31 feet
Source:1970, Surface Water Resources of Iron County,WI:WI-DNR Grand Portage Lake, T43N, R4E, Section 30
Author Aquatic Biologist
Grand Portage Lake Beach was assessed for the 2018 listing cycle; E. coli data sample data were clearly below the 2018 WisCALM listing thresholds for the Recreation use. This water was meeting its designated uses and not considered impaired.
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.
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
|WBIC||Official Waterbody Name||Station ID||Station Name||Earliest Fieldwork Date||Latest Fieldwork Date||View Station||View Data|
|2314100||Grand Portage Lake||10002737||Grand Portage Lake||8/29/2000||11/29/2020||Map||Data|
|2314100||Grand Portage Lake||10043194||Grand Portage Lake Beach||7/7/2014||1/1/2015||Map||Data|
Grand Portage Lake is located in the Flambeau Flowage watershed which is 247.18 mi². Land use in the watershed is primarily forest (56.80%), wetland (28.20%) and a mix of open (14.10%) and other uses (0.90%). This watershed has 190.98 stream miles, 10,199.06 lake acres and 43,978.35 wetland acres.
Nonpoint Source Characteristics
This watershed is ranked Not Ranked 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.