Fish and Aquatic Life
Mallalieu Lake is the most downstream impoundment on the Willow River with its dam located at the river mouth. The lake is located in the city of Hudson, village of North Hudson and Town of Hudson. A bacteriological survey conducted in the summer of 1989 indicated that severe bacteriological contamination of the lake was occurring. The water quality standard for bacterial pollution was exceeded throughout the summer and the lake was closed for swimming the entire summer. A sanitary survey of riparian septic systems indicated that several systems were contributing to the contamination of the lake. These sources of contamination have been controlled with the installation of sanitary sewers in the city of Hudson, the village of North Hudson and replacement of failed septic systems in the Town of Hudson.
The city of Hudson received a lakes planning grant in 1990 to assess lake water quality and watershed land uses. The result of the water quality assessment indicate that the impoundment is hypereutrophic. The lake has very poor water clarity and high levels of nutrients and algae. The study also document the widespread occurrence of Eurasian watermilfoil (Myriophyllum spicatum) in the lake. This is the first documented occurrence of eurasian milfoil in St. Croix county.
Author Surface Water Inventory Of Wisconsin
Mallalieu Lake is a hardwater, drainage impoundment situated on the Willow River near its outlet at Hudson. This flowage has a navigable inlet and a 20 foot head public utility dam (Northern States Power Co.) on its outlet (59 CFS). It is managed for largemouth bass and panfish. The panfish species include perch, bluegills, black crappies, pumpkinseeds and black bullheads. There are also northern pike, walleyes, carp, quillback, white suckers, redhorse and sheepshead present. Access may be had from a landing off Highway 35, where the city owns approximately 250 feet of flowage frontage. One resort is available and 45 dwellings and cottages have developed much of the shoreline. Muskrats, beaver and broods of mallards, blue-winged teal, wood ducks and hooded mergansers inhabit the 76 acres of predominantly willow shrub wetlands at the flowage's inlet. Coot and other members of the puddle and divingduck groups are also found here during migratory seasons. There is a licensed private fish hatchery on an impounded spring area at the flowage's east end.
Source: 1961, Surface Water Resources of St.Croix Co.
Mallalieu Lake T. 29 N., R. 19, 20 W., Sec. 13, .18, 19, 24
Surface Acres 282.0 S.D.F. = 3.12 Maximum Depth = 17 feet
Author Surface Water Inventory Of Wisconsin
Lake Mallalieu is a 270 acre flowage near the mouth of the Willow River. The Willow River is the only inlet stream to Lake Mallalieu. The first dam was constructed in forming the lake in 1848. The present dam was constructed in 1934 after the former had washed out in April of that year. Lake Mallalieu has
a maximum water depth of 17 feet with a mean depth of 5 feet. The watersheds primary land use is urban/residential, agriculture and woodlands.
Lake Mallalieu is considered to be a hypereutrophic lake with poor water quality due to high nutrient levels, high algal concentrations, and poor water clarity. There were a total of 24 species of aquatic plants found in Lake Mallalieu during the 1998 survey (Konkel 1999). Included were three non- native species: Lythrym salicaria (purple loosestrife), Myriophyllum spicatum (Eurasian water milfoil), and Potamogeton crispus (curly-leaf pondweed). Nonpoint source pollution from agricultural operations throughout the watershed has been contributing phosphorous and nitrogen loading, adding to subsequent water quality deterioration.
Lake Mallalieu has an abundant source of large woody debris along certain parts of the flowage. Residential and shoreline development has eliminated large woody debris and natural vegetative buffers in numerous locations throughout the lake. Many shoreline lots have been converted to limestone rip-rap, which has been proven to benefit young smallmouth bass, but may also fail to provide both juvenile and adult fish cover for most other fish species. Preservation of large woody debris and natural shoreline buffers consisting of emergent and submergent plant beds, trees, shrubs, grasses and forbs will assure survival of healthy fish and aquatic life resources. Despite these impacts, Lake Mallalieu currently provides an abundant and diverse sportfish community. Both largemouth and smallmouth bass fishing is excellent with many trophy bass present. Northern pike densities are low; however, the size distribution is well above average. Panfish populations are good but growth rates and large adult densities are lower than expected for small fertile flowages.
Author Kathy Bartilson
Lake Mallalieu (WBIC 2607100) was placed on the 303(d) impaired waters list for eutrophication and pH from total phosphorus in 2004. Excess algal growth impairment was added in 2016. The 2018 assessments showed continued excess algal growth; new chlorophyll-a sample data exceeded the 2018 WisCALM listing thresholds for the Recreation use. Based on the most updated information, no change in the existing impaired waters listing was needed.
Author Ashley Beranek
This lake was placed on the 303(d) impaired waters list for eutrophication and pH from total phosphorus in 2004. The 2016 assessments showed continued impairment by phosphorus; total phosphorus sample data exceeded 2016 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use. Based on the most updated information a REC total phosphorus and excess algal growth impairment was added. This water remains impaired for total phosphorus.
Author Aaron Larson
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.
During 2008, the WDNR worked cooperatively with the St. Croix Watershed Research Station to develop a TMDL planning initiative in the Willow River Watershed. This plan is near completion. In order to achieve a 20% reduction of phosphorus to the St. Croix River, phosphorus reduction in the uplands is needed to meet the goal reduction.
Stormwater Planning, Implementation
Lake Management Plan Development
Monitoring work for Lake Mallileu - TMDL in development with TP,TSS, he lake is designated as high priority for eutrophication and ph impairments due to excess phosphorus, while the upstream reach of the river is a low priority for dissolved oxygen impairments. The river?s designation is due to excess phosphorus and biological oxygen demand (BOD).
Lake Mallalieu is a man made riverine lake located within the channel of the Willow River. Since 2004, Lake Mallalieu and an upstream reach of the Willow River have been included on the Environmental Protection Agency?s (EPA) 303(d) impaired waters list. The lake is designated as high priority for eutrophication and ph impairments due to excess phosphorus, while the upstream reach of the river is a low priority for dissolved oxygen impairments. The river?s designation is due to excess phosphorus and biological oxygen demand (BOD).
The Willow River has become degraded by excess nutrients, specifically phosphorus.
Management to improve the aquatic macrophyte community should
improving water qualit by expanding the buffer of natural shoreline and protecting wetlands in the watershed,
Lake Mallalieu TMDL Development
Cropland runoff should be addressed to lower the export of nutrients and sediments. This will benefit all tributary
streams, lakes, the Willow mainstem, and downstream waters such as the St. Croix River (Lake St. Croix). This is being
addressed through development of the Lake Mallalieu TMDL Implementation Plan.
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|
|2607100||Mallalieu Lake||563121||Lake Mallalieu - Deep Hole||9/12/1973||7/18/2022||Map||Data|
|2607100||Mallalieu Lake||10005432||Lake Mallalieu||8/7/1991||4/2/2022||Map||Data|
|2607100||Mallalieu Lake||563146||St. Croix River - Orange St. Ramp||Map||Data|
|2607100||Mallalieu Lake||564006||Mallalieu Lake - Mallalieu Lake||8/28/1979||9/11/2003||Map||Data|
|2607100||Mallalieu Lake||563132||Lake Mallalieu - Mid-Lake||5/24/2006||9/13/2006||Map||Data|
|2607100||Mallalieu Lake||10018188||Lake Mallalieu -- Access||7/21/2006||7/28/2013||Map||Data|
Mallalieu Lake is located in the Lower Willow River watershed which is 164.38 mi². Land use in the watershed is primarily agricultural (32.10%), forest (25.40%) and a mix of grassland (23.70%) and other uses (18.80%). This watershed has 99.33 stream miles, 2,139.74 lake acres and 2,482.81 wetland acres.
Nonpoint Source Characteristics
This watershed is ranked High for runoff impacts on streams, Not Ranked 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.