Lake Ripley Beach, Lower Koshkonong Creek Watershed (LR11)
Lake Ripley Beach, Lower Koshkonong Creek Watershed (LR11)
Lake Ripley Beach (809600)
0.09 Miles
0 - 0.09
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.
Deep 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.
This inland beach is impaired
Recreational Restrictions - Pathogens
E. coli
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.
Deep Lowland
Deep 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.


Rock River Water Quality Management Plan, Lower Rock River Appendix. WT-668-2002. South Central Region, WDNR.

Lake Ripley, a small kettle lake, has good water quality and a very good sport fishery. Much of the lake's shoreline is developed with the village of Cambridge on the west end and summer cottages and year-round homes on the north and south shores. There is a wetland on the east end of the lake that remains undeveloped. Agricultural runoff contributes nutrients and sediments to the lake, and the village of Cambridge and lake cottages and homes also degrade the lake's water quality. Excess nutrients has spurred the growth of Eurasian water milfoil, an aggressive non-native plant, in the lake. a 1989 aquatic plant survey indicates milfoil, which grows in the lake in depths from roughly 2 to 12 feet, has spread to about 50 percent of the lake, concentrating boat traffic in the lake's middle.

Lake Ripley has been the subject of a small-scale priority watershed project since 1994, when its appraisal report was published. The appraisal work indicates that the lake's water quality is on a continued steady decline due to excess phosphorus and sediment inputs. In former years these inputs were almost exclusively from agricultural fields. Residential development of the lake's immediate subwatershed, including 70 percent of its direct shoreline, contributes to high levels of phosphorus and sediment, has lowered aquatic species diversity, and threatens the survival of the Blanding's turtle, an endangered species in Wisconsin.

In 1993 the lake experienced its first reported blue-green algae bloom. High precipitation levels that year and ensuing years have contributed to the influx of pollutants, reflecting the primary source of nutrients--watershed contributions. Lake Ripley is dimictic, meaning it stratifies twice yearly, becoming anoxic in its hypolimnion during winter and summer. This condition likely contributes phosphorus from in-lake sediment during spring and fall mixing; WDNR researchers are involved in estimating in-lake sediment contributions to overall phosphorus loading rates. The lake's priority watershed plan should guide management efforts into the future.

Date  2002

Author   Aquatic Biologist

Historical Description

Source: 1968, Surface Water Resources of Jefferson County (Lake) Ripley, T6N, R13E, Section 7, 8

A small, deep, compound kettle lake in the end moraine at Cambridge. The lake drains to Koshkonong Creek, over a low-head rubble sill at the outlet. The water is clear and very hard, over a bottom primarily composed of sand and gravel. A good fishery exists for northern pike, walleye, yellow perch, largemouth bass, bluegills and black crappies. Access is provided by several road ends, generally unimproved. A village park on the south shore provides multiple use access. Boat liveries and a scout provide multiple use access. About 130 acres of marshland provide for mallard and blue-winged teal nesting and northern pike spawning.

Surface Acres = 433.0, S.D.F. = 1.40, Maximum Depth = 50 feet

Date  1968

Author   Surface Water Inventory Of Wisconsin

Lake Ripley Beach, Lower Koshkonong Creek Watershed (LR11) Fish and Aquatic LifeLake Ripley Beach, Lower Koshkonong Creek Watershed (LR11) RecreationLake Ripley Beach, Lower Koshkonong Creek Watershed (LR11) Fish Consumption

General Condition

Lake Ripley was evaluated every two-year cycle from 2014 to 2022; phosphorus and algae data indicated a healthy system. This lake is on the Healthy Waters List.

Date  2022

Author  Ashley Beranek

Impaired Waters

Lake Ripley Beach was evaluated for bacteria in the 2022 cycle; E. coli levels were above listing thresholds as outlined in 2022 WisCALM. This beach was added to the 2022 Impaired Waters List.

Date  2022

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
Partnering with property owners, the applicant is sponsoring a grant to implement water quality and habitat best practices from Wisconsin's Healthy Lakes Implementation Plan.
Develop/Distribute Newsletter
Diagnostic/Feasibility Assessment
assessment of restoring several native, non-game fish species to lake
Informational Meetings
Share information at WI Lakes Convention
Issue News/Media Release
Monitor Fish Community
Lake Management Plan Development
Informational Meetings
Protect Riparian or Shorelands
Lake Ripley Management District proposes to undertake a shoreline stabilization and restoration project at the Hoard-Curtis Scout Camp shoreline on Lake Ripley, Jefferson County. They will install riprap off-shore of the existing shoreline (DNR permit already issued), plant aquatic plants inland of that riprap, and do upland seeding (to supplement previously completed plug plantings) after invasive weed and brush removal.
Map Depth of Lake (Bathymetry)
The Lake Ripley Management District will purchase a 65.926-acre parcel of the James & Jane Johnson property in the Town of Oakland, Jefferson County. The property will link the 100-acre Lake Ripley Preserve to 40 acres of DNR-owned wetlands along Lake Ripley's only inlet. This purchase would also ensure the protection, in perpetuity, of a critical stream corridor and wetland/floodplain complex within the headwaters region of Lake Ripley.
Lake Classification
Jefferson County Land and Water Conservation Department will undertake a lake classification process. The resulting lake classification system will enable the County and other lake management entities to implement appropriate lake management strategies in a priority -driven and efficient manner. It will result in the protection and restoration of the water quality and natural ecosystems of the lakes in Jefferson County.
Land Acquisition
Lake Ripley Management District will acquire about 99 acres of croplands and wetlands that help make up the only inlet to Lake Ripley. The acquisition project consists of two parts; 1) about 63 1/2 acres of farmed/wetland and 2) about 35 1/2 acres of drained wetland.
Nine Key Element Plan
Lake Ripley PWS Plan - Nine Key Element Plan - The Lake Ripley Priority Lake Project plan assesses the nonpoint sources of pollution in the Lake Ripley Watershed and guides the implementation of nonpoint source control measures. These control measures are needed to meet specific water resource objectives for Lake Ripley and its tributary. The primary objective of the project is to reduce nonpoint source pollution to the lake.

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

Lake Ripley is located in the Lower Koshkonong Creek watershed which is 265.61 miĀ². Land use in the watershed is primarily agricultural (54.20%), wetland (11.60%) and a mix of grassland (10.50%) and other uses (23.70%). This watershed has 283.47 stream miles, 1,735.65 lake acres and 18,171.94 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.This water is ranked High Lake for individual InlandBeachs based on runoff problems and the likelihood of success from project implementation.

Natural Community

Lake Ripley Beach is considered a Deep Lowland 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.

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