Impairment Unknown, Excess Algal Growth
Fish and Aquatic Life
Hemlock Slough, in the Crossman Creek and Little Baraboo River Watershed, is a 22.34 acre lake that falls in Sauk County. This lake is managed for fishing and swimming and is currently not considered impaired.
Author Aquatic Biologist
Source: 1971, Surface Water Resources of Sauk County Hemlock Slough, T13N R3E, Sec. 21 Surface area= 12.22 acres, S.D.F. = 2.71, Maximum depth= 12 feet. A drained oxbow of the Baraboo River one mile northwest of LaValle. An earthen dam with a six-foot head and the adjoining Chicago North- western railroad track dike control the water level and enhance the sport fishery. The slough was treated with rotenone in 1964 in an attempt to eradicate the carp and other rough fish. Only a partial kill was achieved. The pond was restocked with largemouth bass and panfisb and provides a limited sport fishery at the present time. Northern pike are also present. Muskrat, beaver, mink and puddle ducks inhabit the slough while deer, squirrels, and ruffed grouse are found on the uplands. Public frontage totals 1.33 miles within the very attractive Hemlock County Park. A boat launching ramp and an earthen fishing dike are located on the northern shore.
Author Surface Water Inventory Of Wisconsin
Hemlock Slough (WBIC 1286100) was placed on the impaired waters list for total phosphorus in 2016. The 2018 assessments showed continued impairment by phosphorus; new total phosphorus sample data exceeded the 2018 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use. Chlorophyll-a sample data clearly exceeded the REC thresholds, but only nearly exceed the FAL use thresholds. Based on the most updated information, no change in the existing impaired waters listing was needed.
Author Ashley Beranek
Hemlock Slough (1286100) was assessed during the 2016 listing cycle; total phosphorus and chlorophyll sample data exceeded 2016 WisCALM listing thresholds for the Recreation use, but did not exceed Fish and Aquatic Life thresholds.
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.
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|
|1286100||Hemlock Slough||10018022||Hemlock Slough -- Access||6/25/2012||9/30/2013||Map||Data|
|1286100||Hemlock Slough||10005444||Hemlock Slough||7/27/1999||9/22/2017||Map||Data|
|1286100||Hemlock Slough||10037189||Hemlock Slough - South End||7/26/2012||1/1/2015||Map||Data|
|1286100||Hemlock Slough||10014909||Hemlock Slough - Spring Boomshocking||Map||Data|
Hemlock Slough is located in the Crossman Creek and Little Baraboo River watershed which is 213.80 mi². Land use in the watershed is primarily forest (36.40%), grassland (32.90%) and a mix of agricultural (20.40%) and other uses (10.30%). This watershed has 466.61 stream miles, 244.11 lake acres and 6,321.59 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.
Hemlock Slough is considered a Shallow Headwater 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.