Where is Lake Ripley?

Lake Ripley is a lake in Jefferson County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.

Is Lake Ripley safe to swim in?

Based on E. coli testing, Lake Ripley frequently exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 21.8% of 119 samples across 9 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Lake Ripley is safe to swim in today is a call for Wisconsin's water agency and the county health department; check their current beach advisories before you swim.

What is the water temperature of Lake Ripley?

Lake Ripley typically sits around 77°F at the surface in August, from 10 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Lake Ripley?

Lake Ripley has a maximum depth of 44 feet. The lake covers 420 acres.

What fish are in Lake Ripley?

Fish species found in Lake Ripley include Panfish, Largemouth Bass, Northern Pike, Walleye. Lake Ripley is located in Jefferson County, Wisconsin.

Does Lake Ripley have blue-green algae?

There is no recent EPA CyAN cyanobacteria estimate for Lake Ripley (clouds, ice, or an off-season gap). The most recent reading was moderate (50,119 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.

Are there boat ramps on Lake Ripley?

Lake Ripley has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Island Lane. Public access is listed as yes.

Can I fish at Lake Ripley?

Lake Ripley has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.

Lake Ripley

Jefferson County, Wisconsin420 acresView map Directions

Wisconsin DNR publishes the water-quality measurements for Lake Ripley. Here is what has been measured.

Clarity

9 ft

Typical for Wisconsin

Secchi · sampled 2026

Phosphorus

21.8 µg/L

Typical for Wisconsin

Measured by Wisconsin DNR

Water temp

~77°F

Typical for Aug · EPA WQP

Max depth

44 ft

Bathymetric survey

Area

420 acres

Surface area

Type

Mesotrophic

Trophic class

Mesotrophic
3 aquatic invasives
44 ft max depth
Public access

See the measurements Directions Where to stay

Lake Ripley in Jefferson County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 9 ft visibility. Phosphorus: 21.8 µg/L. Maximum depth: 44 ft. Surface area: 420 acres.

Wisconsin DNR lists Panfish as common on Lake Ripley. DNR survey details →

Loading map…

Lake Ripley is a 420-acre mesotrophic lake in Jefferson County, Wisconsin with a maximum depth of 44 feet. Overall water quality is improving over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 6 other monitored lakes in Jefferson County, Lake Ripley ranks #3 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-29. Methodology: how these readings are compared.

Lake Ripley covers about 420 acres in Jefferson County. It has one public boat landing. Vrbo is where to look for cabins and lake homes around Lake Ripley, and Booking.com and Expedia search hotels near the lake for your dates.

What Lake Ripley is good for

From access and monitoring records, not editorial picks.

Boat launch1 documented ramp
Fishing4 species recorded
Deep water44 ft surveyed max depth

Swimming conditions

Readings only

Bacteria tested: exceedances

Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Bacteria testing record

from E. coli testing · 119 samples, 9 seasons

Based on E. coli testing, Lake Ripley frequently exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 21.8% of 119 samples across 9 seasons.

This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Wisconsin’s current beach and health-department advisories before swimming.

Whether Lake Ripley is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

Compare swimming lakes near Madison →

Get alerts for Lake Ripley →

Water quality measurements for Lake Ripley

These are the measurements Wisconsin DNR publishes for Lake Ripley, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

Moderate clarity, visible to about 9 ft. Phosphorus 21.8 µg/L. TSI 47.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)	9ft	Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	21.8µg/L	Good GoodFairPoor
Chlorophyll-a (algae)		No reading The green pigment in algae — a direct measure of how much algae is in the water.
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.	47	Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic

Moderate nutrients, good water quality

Ask about Lake Ripley

Answers come straight from the public measurements and survey records on this page.

Water Temperature

Lake Ripley typically sits around 77°F at the surface in August. Summer average is about 77°F. Usually warmest in Jul (about 82°F) and coldest in Mar (about 45°F). These are typical values by month — not a live reading.

Jan

Feb

45°

Mar

Apr

May

73°

Jun

82°

Jul

77°

Aug

Sep

Oct

Nov

Dec

Column height runs from this lake’s coldest month (45°F) to its warmest (82°F).

Typical surface water temperature by month, from 10 field readings (2024–2025) via the EPA Water Quality Portal. See the full Lake Ripley water temperature breakdown →

Blue-Green Algae (Cyanobacteria)

No current satellite reading

There’s no recent EPA CyAN cyanobacteria estimate for Lake Ripley — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (50,119 cells/mL) on March 8, 2026.

Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗

DNR fisheries survey

Wisconsin DNR lists Panfish as common on Lake Ripley.

A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lake Ripley’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1989. 5 stations on file (most recent sample 2026).

DNR Assessment

Good · Deep Lowland lake

Trophic State Index 47 (mesotrophic) · 5-year average

Fish Species (DNR-rated)

Panfish(Common)Largemouth Bass(Common)Northern Pike(Common)Walleye(Common)

Contour map (PDF) →Full WI DNR LakePage →Water quality stations →

DNR Reports & Resources

Wisconsin DNR Fisheries scientists publish multi-year survey reports for Lake Ripley covering fish populations, stocking, water quality, and management. 1 report on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

2023
Lake Ripley comprehensive survey, 2023
Comprehensive Survey · WI DNR · 2023 (PDF)

Lake Details

Max depth

44 ft

Surface area

420 acres

Public access

Yes

Listed by Wisconsin DNR

Lake Size & Watershed

Watershed (drainage) area

1 sq mi

HydroLAKES / HydroSHEDS

Shoreline

4 mi

HydroLAKES / HydroSHEDS

Elevation

830 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

Boat Landings

Yes

Public Access

Island LanePublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Stays via Stay22

Stays near Lake Ripley

Compare lakeside cabins, hotels, and vacation rentals near Lake Ripley in Jefferson County, Wisconsin — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.

Top-rated places to stay near Lake Ripley

Prices for Oct 9–11, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Wisconsin’s top lakes →

Follow Lake Ripley’s readings

Email me when new measurements post for this lake. Updates stay free.

Or email

Fish Species

Panfish Largemouth Bass Northern Pike Walleye

Click a species to see every lake where it is documented.

Fishing Lake Ripley

Invasive & Introduced Species

Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.

Chinese Mystery SnailCurly-Leaf PondweedEurasian Water-MilfoilHybrid Eurasian / Northern Water-MilfoilPurple LoosestrifeZebra Mussel

Water Quality Trend: Improving

Based on 7 years of monitoring (2020–2026).

Water clarity
Improving
6 years
Phosphorus
Improving
-1.23 µg/L/yr7 years

See year-by-year chart →

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Lake Ripley under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.

Cambridge Oakland Wastewater Commission
Cambridge · 0.4 mi away · NPDES WI0026948
Recent violation

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

Nearby Lakes in Jefferson County

Hope Lake8 ft clear—View →Red Cedar Lake4 ft clear · Eutrophic—View →Bean Lake—View →Mud Lake2.3 ft clear · Eutrophic—View →

Rock Lake12 ft clear · MesotrophicCompare—View →

Mud Lake—View →

Frequently asked questions about Lake Ripley

Where is Lake Ripley?: Lake Ripley is a lake in Jefferson County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Lake Ripley?: Lake Ripley in Jefferson County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 9 ft visibility. Phosphorus: 21.8 µg/L. Maximum depth: 44 ft. Surface area: 420 acres.
Is Lake Ripley safe to swim in?: Based on E. coli testing, Lake Ripley frequently exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 21.8% of 119 samples across 9 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Lake Ripley is safe to swim in today is a call for Wisconsin's water agency and the county health department; check their current beach advisories before you swim.
What is the water temperature of Lake Ripley?: Lake Ripley typically sits around 77°F at the surface in August, from 10 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Lake Ripley?: Lake Ripley has a maximum depth of 44 feet. The lake covers 420 acres.
What fish are in Lake Ripley?: Fish species found in Lake Ripley include Panfish, Largemouth Bass, Northern Pike, Walleye. Lake Ripley is located in Jefferson County, Wisconsin.
What did the DNR fisheries survey find at Lake Ripley?: Wisconsin DNR lists Panfish as common on Lake Ripley. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lake Ripley’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Does Lake Ripley have blue-green algae?: There is no recent EPA CyAN cyanobacteria estimate for Lake Ripley (clouds, ice, or an off-season gap). The most recent reading was moderate (50,119 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Lake Ripley?: Lake Ripley has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Island Lane. Public access is listed as yes.
Can I fish at Lake Ripley?: Lake Ripley has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.

Explore Lake Ripley across LakeQuality

Wakesurfing on Lake Ripley

Depth, room, public access, and the state wake-sport rules

Wisconsin Fishing Guide

Fish species and the cleanest lakes across Wisconsin

Jefferson County Fishing

Fish species and best lakes in Jefferson County

Lake Fishing Forecast

Species activity outlook by water temperature and season

Wisconsin Lake Trips

Where to stay at Wisconsin's top lakes, each with its readings

The State of Wisconsin's Lakes

Wisconsin's cleanest lakes, ranked on agency measurements

More lakes in Wisconsin

Clearest lakes in Wisconsin

Ranked by Secchi water clarity

All Wisconsin lakes

Every Wisconsin lake with its Wisconsin DNR measurements

Lake water quality by country

Official ratings and named-lake measurements

State Parks Near Lake Ripley

Aztalan State Park

State Park · 7.9 mi

Lake Kegonsa State Park

State Park · 12.2 mi

Capital Springs State Recreation Area

State Recreation Area · 17.5 mi

Governor Nelson State Park

State Park · 24.2 mi

Other Lakes in Wisconsin

Lake Waubesa

Dane County · 3.2 ft

Whitewater Lake

Walworth County · 4 ft

Turtle Lake

Walworth County · 11 ft

Lake Wingra

Dane County · 4 ft

Golden Lake

Waukesha County · 12.8 ft

Green Lake

Walworth County · 11 ft

Mesotrophic Lakes in Wisconsin

Turtle Lake Golden Lake Green Lake Middle Lake

Compare Lake Ripley With Nearby Lakes

Lake Ripley vs Lake Koshkonong

Jefferson County · 1.7 ft

Lake Ripley vs Rock Lake

Jefferson County · 12 ft

Where this data comes from

64 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

Wisconsin Department of Natural ResourcesWIDNR_WQX64 samples · 2020–2026

Analytical methods

Phosphorus by Colorimetry

Monitoring station identifiers (1)

WIDNR_WQX-283122

EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.

Other records on this page

Regulated discharger data from EPA ECHO (ICIS-NPDES)

Lake size & watershed from HydroLAKES (HydroSHEDS)

Fish and recreation data from Wisconsin DNR Lakes

Named boat-access points from the USGS National Boat Ramps inventory