Lake Ripley
Lake Ripley in Jefferson County, Wisconsin has a water quality grade of B (Good). Water clarity: 9 ft visibility. Phosphorus: 21.8 µg/L. Maximum depth: 44 ft. Surface area: 420 acres.
- Clarity
- 9 ft
- Typical in August
- 77°F
- Max depth
- 44 ft
- Area
- 420 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Jefferson County
Lake Ripley is a 420-acre mesotrophic lake in Jefferson County, Wisconsin with a maximum depth of 44 feet. Water quality is graded B based on 1 sampling years through 2026. 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. Grade methodology: LakeGrade methodology.
Watch Lake Ripley water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyBacteria D
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
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.
Water Quality Grade: B (Good)
Moderate clarity, visible to about 9 ft. Phosphorus level: 21.8 µg/L. Trophic State Index: 47.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9 ft | Not graded |
| Phosphorus | 21.8 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 47 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay 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
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 →
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.
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)
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 ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 44 ft |
| Surface Area | 420 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Island LanePublic
Fish Species
Click a species to see every graded 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.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1989. 5 stations on file (most recent sample 2026).
Fish Species (DNR-rated)
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).
- 2023Lake Ripley comprehensive survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.539 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.23 µg/L/yr | 7 |
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 CommissionCambridge · 0.4 mi away · NPDES WI0026948Recent 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.
County Ranking
Ranked #3 of 7 lakes in Jefferson County
Nearby Lakes in Jefferson County
Frequently asked questions about Lake Ripley
What is the water quality grade for Lake Ripley?
- Lake Ripley in Jefferson County, Wisconsin has a water quality grade of B (Good). 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 works out to a bacteria swim-safety grade of D — a historical summary of past testing, not a current reading. Lake Ripley has a water quality grade of B (Good). Bacteria levels can spike quickly after heavy rain, so always check Wisconsin's current beach and health-department 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.
Explore Lake Ripley across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Wisconsin
Fish species and best lakes in Jefferson County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its grade
Moderate nutrients, good water quality
Wisconsin's cleanest and most-polluted lakes, ranked
More Wisconsin Lake Rankings
State Parks Near Lake Ripley
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
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 Resources
WIDNR_WQX64 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated 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