Six Mile Creek, Six Mile and Pheasant Branch Creeks Watershed (LR10)
Six Mile Creek, Six Mile and Pheasant Branch Creeks Watershed (LR10)
Six Mile Creek (805500)
3.58 Miles
8.50 - 12.08
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.
Cool-Cold Mainstem, Cool-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.
2024
Poor
 
This river is impaired
High Phosphorus Levels
Total Phosphorus
 
Dane
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.
No
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.
Yes
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.
Yes

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.
Restricted Aquatic Life
Fish and Aquatic Life communities are not fully supported in this ecosystem.
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.
LFF
Streams capable of supporting small populations of forage fish or tolerant macro-invertebrates that are tolerant of organic pollution. Typically limited due to naturally poor water quality or habitat deficiencies. Representative aquatic life communities associated with these waters generally require warm temperatures and concentrations of dissolved oxygen that remain above 3 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.
WWSF
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.

Overview

Sixmile Creek Water quality in Six Mile Creek's 12-mile length is generally good, supporting a limited forage fishery west of Hwy 113, a diverse forage and warm water sport fishery from Hwy 113 to Lake Mendota, and abundant spawning areas. Six Mile Creek's 43-square-mile watershed is predominately agricultural (63%) but also includes the rapidly urbanizing village of Waunakee (WDNR 1996b). From 1995 to 2000, the village grew by 25%, to roughly 9,000 people. Waunakee's wastewater effluent is treated at the Madison Metropolitan Sewerage District (MMSD). Upstream of the village, Waunakee Marsh traps sediment from the area's row-cropped fields, which is adversely affecting the wetland's ecology.

Downstream of the village of Waunakee to Lake Mendota urban development threatens the stream. Several small rural communities and large developments lie in the drainage area outside of the village, contributing pollutants from agricultural land spreading, construction site erosion, and habitat loss. In Summer 1991, Stokely's wastewater spray irrigation system--which landspreads its canning waste on 178 acres just outside of the village--malfunctioned, causing fish kills in Six Mile Creek. This incident was not the first caused by Stokely's landspreading operations. Fish kills in Six Mile Creek occurred three times in a short two-year period. The July 12, 1991 spill released 6,000 gallons of untreated wastewater directly into the creek. This spill followed on the heels of a pipe leak July 1, 1991, during which 85,000 gallons of wastewater drained into the creek. In 1990 a spill released to the creek 230,000 gallons from a pipe leak (WDNR 1996a). Fish managers estimate hundreds to thousands of pike, walleye, bass etc., fingerlings were killed in the last incident, as a fish rearing marsh for Lake Mendota is located just off the creek.

A recent fishkill on Six Mile Creek on July 2, 2001, resulted in the death of over 200 fish (white suckers and creek chubs) near Madison Street Bridge in Waunakee. The fishkill coincided with the flushing of a new water main. New water mains are typically more heavily chlorinated as a means to sanitize and disinfect before bringing the main online. It s likely that this flushing event depressed oxygen levels or contained high levels of chlorine, resulting in a fishkill.

Date  2002

Author   Aquatic Biologist

Historical Description

Six Mile Creek originates in Section 2 of Springfield Township (T8N, R8E) and flows east to Waunakee and south to the north end of Lake Mendota. The watershed once encompassed plentiful wetlands, but many of these areas have been drained, filled, or altered for the development of more cropland. Two major remaining wetlands are the Waunakee Marsh in the northwestern part of the watershed and the marshes near the creek's mouth on Lake Mendota (Dane Cty. Reg. Plann. Comm. 1979a). Channel alterations in the upper reaches of the creek and sewage effluent contribute to the high sediment load. Much of the creek bottom is heavily silted. The marshes serve as sediment traps and also contrIbute ground water seepage to the creek. Six Mile Creek supports a diverse forage and warm water game fishery and offers abundant spawning areas for fish from Lake Mendota. The creek has a history (as recent as 1980) of fishkills near Waunakee caused by discharges of biochemical oxygen demand (BOD) waste from a canning factory with a defective land irrigation disposal system. There are no other known point sources of pollution on the creek and water quality is good. Public access is available at state and city parks, the DNR-owned portion of the Waunakee Marsh and 19 road crossings. The Waunakee Marsh supports a varied habitat for pheasants, waterfowl, rabbits, deer, and furbearers.
Fish species: bowfin, central mudminnow, northern pike, stoneroller (unsp.), common carp, golden and common shiner, southern redbelly dace, bluntnose and fathead minnow, creek chub, white sucker, pearl dace, bullhead (unsp.), black and yellow bullhead, channel catfish, brook stickleback, white bass, green sunfish, pumpkinseed, blueglll, largemouth bass, white and black crappie, yellow perch, freshwater drum, and walleye.

Six Mile Creek -T8N, R9E, Sec. 28, Surface acres = 14.5, Length = 12 miles, Stream order = II, Gradient = 7.2 ft/mile, Base discharge = 16.4 cfs.
From: Day, Elizabeth A.; Grzebieniak, Gayle P.; Osterby, Kurt M.; and Brynildson, Clifford L., 1985. Lake and Stream Classification Project. Surface Water Resources of Dane County, Wisconsin Department of Natural Resources, Madison, WI.

Date  1985

Author   Aquatic Biologist

Six Mile Creek, Six Mile and Pheasant Branch Creeks Watershed (LR10) Fish and Aquatic LifeSix Mile Creek, Six Mile and Pheasant Branch Creeks Watershed (LR10) RecreationSix Mile Creek, Six Mile and Pheasant Branch Creeks Watershed (LR10) Fish Consumption

Impaired Waters

Six Mile Creek, from mile 8.5 to 10, was evaluated in the 2022 cycle: phosphorus levels were above listing thresholds as outlined in 2022 WisCALM. This stream was added to the 2022 Impaired Waters List.

Date  2022

Author  Ashley Beranek

Impaired Waters

The 2018 assessments of Sixmile Creek (miles 0-8.5) showed continued impairment by phosphorus; new total phosphorus sample data overwhelmingly exceeded the 2018 WisCALM listing criteria for the Fish and Aquatic Life use. However, available biological data did not indicate impairment (i.e. no macroinvertebrate or fish Index of Biotic Integrity (IBI) scored in the "poor" condition category). Based on the most updated information, no change in the existing impaired waters listing was needed.

Date  2017

Author  Ashley Beranek

Impaired Waters

Sixmile Creek (805500) was assessed during the 2016 listing cycle; total phosphorus sample data overwhelmingly exceed 2016 WisCALM listing thresholds for the Fish and Aquatic Life use, however, available biological data do not indicate impairment (i.e. no macroinvertebrate or fish Index of Biotic Integrity (IBI) scored in the "poor" condition category). Chloride sample data clearly met 2016 WisCALM chronic and acute listing criteria for the Fish and Aquatic Life use.

Date  2015

Author  Aaron Larson

Condition

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.

Reports

Recommendations

Citizen-Based Stream Monitoring
Collect chemical, physical, and/or biological water quality data to assess the current overall stream health. The data can inform management decisions and may be used to identify impaired waters for biennial lists.
Citizen-Based Stream Monitoring
Collect chemical, physical, and/or biological water quality data to assess the current overall stream health. The data can inform management decisions and may be used to identify impaired waters for biennial lists.
Citizen-Based Stream Monitoring
Collect chemical, physical, and/or biological water quality data to assess the current overall stream health. The data can inform management decisions and may be used to identify impaired waters for biennial lists.
Citizen-Based Stream Monitoring
Collect chemical, physical, and/or biological water quality data to assess the current overall stream health. The data can inform management decisions and may be used to identify impaired waters for biennial lists.
Runoff Grant
wet detention pond, Waunakee
County Land and Water Management Plan
Dane County will undertake a River Planning Grant project to incorporate an urban analysis component within the SWAT (Soil and Water Assessment Tool) model. Project deliverables are as follows: 1.) Develop a revised SWAT model that can reliably simulate runoff from both urban and rural sources within the Six Mile Creek Watershed, 2.) Provide a summary of the modeling approach and modeling results in the final report; 3.) revised SWAT model will be an open source model available at no charge for other users.
Sewer Service Area Planning
Waunakee is a growing community and works cooperatively with the Town of Westport to provide municipal urban services to commercial and residential customers in the incorporated area.

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

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

Sixmile Creek is located in the Six Mile and Pheasant Branch Creeks watershed which is 119.45 miĀ². Land use in the watershed is primarily agricultural (45%), suburban (15.70%) and a mix of open (13.20%) and other uses (26.00%). This watershed has 145.61 stream miles, 9,959.08 lake acres and 2,759.80 wetland acres.

Nonpoint Source Characteristics

This watershed is ranked Not Available for runoff impacts on streams, Not Available for runoff impacts on lakes and High for runoff impacts on groundwater and therefore has an overall rank of High. 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

Six Mile Creek is considered a Cool-Cold Mainstem, Cool-Warm Mainstem under the state's Natural Community Determinations.

Natural communities (stream and lake natural communities) represent model results and 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.

Cool (Cold-Transition) Mainstem streams are moderate-to-large but still wadeable perennial streams with cold to cool summer temperatures. Coldwater fishes are common to uncommon, transitional fishes are abundant to common, and warm water fishes are uncommon to absent. Headwater species are common to absent, mainstem species are abundant to common, and river species are common to absent.