Fish and Aquatic Life
This stream originates from several spring-fed streamlets in an area of bedrock outcroppings in the Gogebic-Penokee Iron Range subsection, flowing about 11 miles to its confluence with Long Lake Branch in the Bibon Marsh. Its primary feeders are an unnamed tributary at T44N R5W S8 and Pre-emption Creek, both of which are excellent spring water trout feeders. All of Twenty Mile Creek is considered trout water and is classified as outstanding resource waters. From the Highway 63 crossing near its confluence with Pre-emption Creek down to the mouth, the stream supports a Class II brook and brown trout fishery. Upstream of Highway 63, the stream is considered Class I waters for brook and brown trout, with the brook trout more common. The stream flows through mostly wild lands with bank vegetation ranging from dense alder to mixed hardwoods and scattered conifer. In and around the town of Grandview, pasturing becomes more common before the stream enters the Bibon Marsh.
The drainage basin experiences rapid runoff, resulting in damage to in-stream cover. Several stream improvement projects were conducted in damaged areas. Beaver and muskrat are common to the stream and waterfowl use the stream during migration. Forest Road 378 in the Chequamegon National Forest parallels the stream in its upper reaches and the potential for forestry activities exists in forested areas of the watershed.
The Grandview wastewater treatment facility discharges effluent to an intermittent and wetland tributary to Twenty Mile Creek, proposed for inclusion in the NR104 list of variance waters as supporting limited aquatic life. Sampling at this site in 1989 and 1991 turned up elevated nutrient levels and a single high level of biochemical oxygen demand below the discharge overflow.
The stream is identified in the Lake Superior Coastal Wetland Evaluation (Epstein 1997) as an aquatic priority site. The entire stream is considered trout water. Macroinvertebrates were very diverse, including 50 taxa, five of which are rare. Fauna is dominated by mayflies, caddisflies and stoneflies. Management concerns include the presence of pastured land in the watershed and some siltation.
From: Turville-Heitz, Meg. 1999. Lake Superior Basin Water Quality Management Plan. Wisconsin Department of Natural Resources, Madison, WI.
Author Aquatic Biologist
Twenty Mile Creek was assessed during the 2018 listing cycle; new biological (fish Index of Biotic Integrity (IBI) scores) sample data were clearly below the 2018 WisCALM listing thresholds for the Fish and Aquatic Life use. This water was meeting this designated use and was 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 2016 . See also 'monitoring' and 'projects'.
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 and implementation of a Total Maximum Daily Load Analysis, habitat restoration work, partnership education and outreach and more. If specific recommendations exist for this water, they will be displayed below.
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
|Project Name (Click for Details)||Year Started|
|WBIC||Official Waterbody Name||Station ID||Station Name||Earliest Fieldwork Date||Latest Fieldwork Date||View Station||View Data|
|2895100||Twenty Mile Creek||10044004||Twentymile Creek at Hwy 63 Bridge||Map||Data|
|2895100||Twenty Mile Creek||10022569||Twenty Mile Creek - Off Wisco Rd 0.9 Miles South From Intersection With Camp 8 Rd - Station #4 ||1/1/2015||1/1/2015||Map||Data|
|2895100||Twenty Mile Creek||10013210||Twenty Mile Creek - 39 m US Camp 8 Rd - Station #3||10/20/2000||1/1/2015||Map||Data|
|2895100||Twenty Mile Creek||10041174||TWENTY MILE CREEK UPSTREAM N. COUNTRY TRAIL FOOT BRIDGE (STATION 5)||1/1/2015||1/1/2015||Map||Data|
Twenty Mile Creek is located in the White River watershed which is 366.15 mi². Land use in the watershed is primarily forest (70%), wetland (11%) and a mix of grassland (6%) and other uses (12%). This watershed has 472.79 stream miles, 7,218.85 lake acres and 29,057.91 wetland acres.
Nonpoint Source Characteristics
This watershed is ranked Not Ranked for runoff impacts on streams, Not Available 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.