Upper St. Croix Lake, Upper St. Croix and Eau Claire Rivers Watershed (SC18)
Upper St. Croix Lake, Upper St. Croix and Eau Claire Rivers Watershed (SC18)
Upper St. Croix Lake (2747300)
828.28 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.
Shallow Lowland
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 Lowland
Shallow lowland 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.


Upper St. Croix Lake, in the Upper St. Croix and Eau Claire Rivers Watershed, is a 828.27 acre lake that falls in Douglas County. This lake is an outstanding/exceptional resource water under NR102 under the Fisheries Program. This lake is managed for fishing and swimming and is currently not considered impaired.

Date  2011

Author   Aquatic Biologist

Historical Description

This lake is situated at the headwaters of the St. Croix River. In addition to its status as a
major contemporary recreational resource this waterbody occupies a place in history as a part of
the Brule - St. Croix portage. The early European explorers often stopped on this lake in their
journeys from Lake Superior to the Mississippi River.

Upper St. Croix Lake has been nominated as an "Outstanding Resource Water" and has an
excellent fishery as well as providing significant aquatic recreational opportunities. This lake
does exhibit some symptoms of eutrophication that are somewhat unexpected from a waterbody
located at the headwaters of a stream system. The Village of Solon Springs is situated on the
west shore of this lake and did experience some problems with groundwater pollution from
individual sewage disposal systems in the past. This problem has been corrected with the
installation of a municipal collection and treatment system.

A feasibility study to assess the current status of water quality in this lake and the nutrient
budget would be a desireable first step for this lake community. A long range lake management
plan would be the logical goal for this important lake.

This ORW nominated lake should be considered as a high priority for a Priority Lakes project.

Date  1992

Author   Surface Water Inventory Of Wisconsin

Upper St. Croix Lake, Upper St. Croix and Eau Claire Rivers Watershed (SC18) Fish and Aquatic LifeUpper St. Croix Lake, Upper St. Croix and Eau Claire Rivers Watershed (SC18) RecreationUpper St. Croix Lake, Upper St. Croix and Eau Claire Rivers Watershed (SC18) Fish Consumption

General Condition

Upper St. Croix Lake (2747300) was assessed during the 2016 listing cycle; total phosphorus sample data were clearly below 2016 WisCALM listing thresholds for Recreation use and Fish and Aquatic Life use. Chlorophyll sample data were clearly below FAL use listing thresholds and did not exceed REC listing thresholds. This water was also assessed for chlorides and sample data were clearly below 2016 WisCALM chronic and acute listing criteria for the 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.



Control Invasive Species
2747300 Upper Saint Croix Lake
Watercraft Inspections Clean Boats, Clean Waters
2747300 Upper Saint Croix Lake
Nine Key Element Plan
Upper St. Croix - Eau Clair Rivers PWS Plan - Nine Key Element Plan - The Upper St. Croix - Eau Clair Rivers Priority Watershed is at the headwaters of the St. Croix River and the Mississippi River system. The historical significance of this resource is well documented in many accounts referring to the beauty and abundance of this outstanding resource. In 1988, the St. Croix River was designated as an Outstanding Resource Water by the State of Wisconsin. The Upper St. Croix - Eau Clair Rivers watershed project has a protection orientation, as opposed to the more traditional remediation based watershed projects, and takes a proactive approach to prevent nonpoint pollution before it happens.

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

Upper Saint Croix Lake is located in the Upper St. Croix and Eau Claire Rivers watershed which is 277.89 mi². Land use in the watershed is primarily forest (83.90%), wetland (9.50%) and a mix of open (4.30%) and other uses (2.40%). This watershed has 153.93 stream miles, 7,654.41 lake acres and 13,694.48 wetland acres.

Nonpoint Source Characteristics

This watershed is ranked Not Ranked for runoff impacts on streams, Not Ranked for runoff impacts on lakes and Low for runoff impacts on groundwater and therefore has an overall rank of Low. This value can be used in ranking the watershed or individual waterbodies for grant funding under state and county programs.This water is ranked High Lake for individual Lakes based on runoff problems and the likelihood of success from project implementation.

Natural Community

Upper St. Croix Lake is considered a Shallow Lowland 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 lowland lake describes the depth and location of the lake in a watershed. These variables affect the lakes response to watershed variables.