Nagawicka Lake, Bark River Watershed (LR13)
Nagawicka Lake, Bark River Watershed (LR13)
Nagawicka Lake (828000)
980.94 Acres
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.
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.
Shallow headwater lake describes the depth and location of the lake in a watershed. These variables affect the lakes response to watershed variables.
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.
Aquatic Life
Waters that support fish and aquatic life communities (healthy biological communities).
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.


Nagawicka Lake is a large mesotrophic drainage lake on the Bark River. The village of Delafield lies on the southwest edge of the lake and there is significant home and cottage development around the lake. The lake has a good Warm Water Sport Fishery and high recreational use. The lake's major issues are development pressures, lack of stormwater management, and shoreline disturbance. Nutrient and sediment loading from upstream, surrounding agricultural and urban runoff, and erosion from construction sites have affected the lake's quality. Septic systems in non-sewered areas may also be a problem, though almost the entire lake lies within a sewer service area. Applications to conduct dredging along the lake's west shore have been submitted. Recently, the city of Delafield purchased property along the lake to connect with the downtown corridor trail system. There are no lake association or Self-Help monitoring volunteers for this lake. A WDNR Lake Planning Grant could fund development of a long-term lake management plan for the lake, including determining the lake management institutional structure, such as developing a lake association, and protection strategies.

Date  2002

Author   Aquatic Biologist

Historical Description

Source: 1963, Surface Water Resources of Waukesha County Nagawicka Lake T7N, R18E, Sections 8 and 17

A large deep lake occupying the valley drained by the Bark River in the interlobate moraine. The water is clear and most of the bottom is gravel. Both inlet and outlet are traversable by boat with the exception of the dam site. The fishery consists of northern pike, walleyes, large and smallmouth bass, and pan fish. Fishing success has been above average for a number of years. A major-use problem is weeds, which have required treatment nearly every year in the past decade. One county park provides excellent access for multiple use on the east shore. In addition to the lake proper there are 32 acres of water in an extensive channel system on the west shore. A summer camp of 550 capacity additionally provides for high summer use of the lake shores. A small northernmost basin is bordered by timber swamp of high aesthetic and wildlife value. In 1942, a Department evaluation Suggested a waterfowl refuge here.

Surface Acres = 957, S.D.F. = 1.98, Maximum Depth = 90 feet

Date  1963

Author   Surface Water Inventory Of Wisconsin

Nagawicka Lake, Bark River Watershed (LR13) Fish and Aquatic LifeNagawicka Lake, Bark River Watershed (LR13) RecreationNagawicka Lake, Bark River Watershed (LR13) Fish Consumption

General Condition

Nagawicka Lake (828000) was assessed during the 2016 listing cycle; total phosphorus and chlorophyll sample data were clearly below 2016 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use. This water is meeting these designated uses and is not considered impaired.

Date  2015

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.



Best Management Practices, Implement
The City of Delafield will implement best practices described in Wisconsin's 2014-2017 Healthy Lakes Implementation Plan on Nagawicka Lake. Practices include: 350 ft2 native plantings, rain gardens, and diversion practices on 3 properties, including the City\2019s Graham Street demonstration site. The best practices require a contract to remain in effect for 10 years and must include minimum operation and maintenance requirements and data collection as described in grant condition #17.
Habitat Restoration - Shoreland
Practices include: 350 ft2 native plantings, rain gardens, and diversion practices on 3 properties.
Diagnostic/Feasibility Assessment
Diagnostic and feasibility study for Nagawicka Lake to improve and enhance the water quality of the Lake. There will be a final design for the wet detention basins based on the preferred design alternatives selected by the City of Delafield and the DNR. There will be at least 6 formal meetings or presentations in addition to the public information meetings anticipated.
Land Acquisition
The Waukesha Land Conservancy will acquire 2.85 acres of land on Nagawicka Lake for lake protection purposes.
Land Acquisition
The Waukesha Land Conservancy proposes to acquire 12.4 acres of land, including 411 feet of shoreline, situated on Nagawicka Lake in the Village of Nashota, Waukesha County for lake protection purposes.
Land Acquisition
The City of Delafield will acquire approximately .61 acres of land on the western border of Nagawicka Lake for lake protection and public outdoor recreation purposes. Eligible costs include acquisition of the parcel, appraisal fee and preparation of an environmental assessment
Lakes Planning Grant
The village and city of Delafield should apply for a WDNR lake planning grant to develop a long-term lake management plan for Nagawicka Lake, including determining the lake management institutional structure and protection strategies.

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

Nagawicka Lake is located in the Bark River watershed which is 185.84 miĀ². Land use in the watershed is primarily agricultural (29.90%), wetland (22.40%) and a mix of forest (15.20%) and other uses (32.50%). This watershed has 265.69 stream miles, 3,499.26 lake acres and 22,145.94 wetland acres.

Nonpoint Source Characteristics

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

Nagawicka Lake is considered a Two-Story 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.

Shallow headwater lake describes the depth and location of the lake in a watershed. These variables affect the lakes response to watershed variables.