Dell Creek, Dell Creek Watershed (LW26)
Dell Creek, Dell Creek Watershed (LW26)
Dell Creek (1295200)
0.41 Miles
0 - 0.41
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-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.
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.
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.
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.

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.
Fish and Aquatic Life - waters that do not have a specific use designation subcategory assigned but which are considered fishable, swimmable waters.
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.
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.
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.
Default FAL
Fish and Aquatic Life - Default Waters do not have a specific use designation subcategory but are considered fishable, swimmable waters.


Dell Creek is a warm water sport fishery for the lower 1.5 miles and a Class II trout stream for
the upper 10.5 miles of its length. The creek is an exceptional resource water (ERW). The
land use along the stream is agricultural with some woodlands and wetlands. Much of Dell
Creek's length in Sauk County is publicly owned.
The main problems on the creek are sediment and nutrient loading from agricultural sources,
and a lack of in-stream habitat. Surveys conducted in 1995 found low numbers of trout and
determined the water quality to be from fair to poor in some locations. This indicates that the
stream has experienced some severe environmental damage. It is thought that the limited
habitat is one of the limiting factors for aquatic life.

Ripp, Coreen, Koperski, Cindy and Folstad, Jason. 2002. The State of the Lower Wisconsin River Basin.
PUBL WT-559-2002. Wisconsin Department of Natural Resources, Madison, WI.

Date  2002

Author  Cynthia Koperski

Historical Description

Dell Creek is a Class II trout stream for 10.5 miles of its length (WDNR, 1980). All of
Dell Creek in Sauk County has been nominated as exceptional resource waters under
the state's antidegradation program. There are two large impoundments on Dell Creek,
Lake Delton and Mirror Lake. Much of Dell Creek's length in Sauk County is publicly
owned. Silt and sediment from farm fields are thought to be a problem in the stream
and are causing a sediment problem in the upper end of Mirror Lake (Trumm, 1991).
Suspected high nutrient inputs to Mirror Lake from Dell Creek are thought to be fueling
the excessive aquatic plant and algae growth in the lake (Schlesser, 1991-1992, Trumm, 1991).

Date  1994

Author   Surface Water Inventory Of Wisconsin

Dell Creek, Dell Creek Watershed (LW26) Fish and Aquatic LifeDell Creek, Dell Creek Watershed (LW26) RecreationDell Creek, Dell Creek Watershed (LW26) Fish Consumption

Impaired Waters

The 2018 assessments of Dell Creek (Unnamed Stream (WBIC 5029152) to the Sauk-Juneau county line) showed impairment by temperature; new temperature sample data exceeded the 2018 WisCALM listing criteria for the Fish and Aquatic Life use, however, available biological data do not indicate impairment (i.e. no fish Index of Biotic Integrity (IBI) scored in the "poor" condition category). Based on the most updated information, this water was proposed for the impaired waters list.

Date  2017

Author  Ashley Beranek

Impaired Waters

The 2018 assessments of Dell Creek (miles 1.84-7.56) showed continued impairment by phosphorus; new total phosphorus sample data 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


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.



Aquatic Plant Management Plan
Monitor Targeted Watershed Area (TWA)
Dell Creek BMP Evaluation TWA 2017 -2019
Monitor Targeted Watershed Area (TWA)
Monitor the status of streams and rivers in the Dell Creek section 319 funded watershed for BMP evaluation. The department needs current fish, habitat, temperature, water chemistry and macroinvertebrate data for streams in the watershed. The data will be used to determine whether these streams are achieving their attainable use in order to update the watershed tables, determine if Dell Cr. can be removed from the impaired waters list, and assess the overall health of the watershed and BMP effectiveness as required by Section 303(d) of the Clean Water Act.
Nine Key Element Plan
Dell Creek PWS Plan - Nine Key Element Plan - The goal of the Dell Creek Priority Watershed Project is to protect, enhance and restore the surface and groundwater in the watershed 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 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

Dell Creek is located in the Dell Creek watershed which is 133.73 miĀ². Land use in the watershed is primarily forest (48.30%), agricultural (22.50%) and a mix of grassland (11.20%) and other uses (18.00%). This watershed has 231.97 stream miles, 193.10 lake acres and 4,715.88 wetland acres.

Nonpoint Source Characteristics

This watershed is ranked High for runoff impacts on streams, Medium 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

Dell Creek is considered a Cool-Warm Mainstem 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.