Winona Lake
Winona Lake in Douglas County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 2 ft visibility. Phosphorus: 88 µg/L. Chlorophyll-a (algae): 48.5 µg/L. Maximum depth: 9 ft. Surface area: 213.31 acres.
- Clarity
- 2 ft
- Typical in August
- 74°F
- Max depth
- 9 ft
- Area
- 213 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 10
- Open water
- 221 days
Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Winona Lake →
Next lake in Douglas County
Winona Lake is a 213-acre productive, nutrient-rich eutrophic lake in Douglas County, Minnesota with a maximum depth of 9 feet (5-foot average). Water quality is graded F based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 11 documented fish species including black bullhead, black crappie, and bluegill. Public access is available. Compared to the 36 other monitored lakes in Douglas County, Winona Lake ranks #37 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-06. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyAlgae risk
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.
Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom
Water Quality Grade: F (Algae-prone)
Very murky, less than 2 ft of visibility. Phosphorus level: 88 µg/L. Chlorophyll-a: 48.5 µg/L. Trophic State Index: 68.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2 ft | Not graded |
| Phosphorus | 88 µg/L | Poor |
| Chlorophyll-a (Algae) | 48.5 µg/L | Poor |
| Trophic State Index (TSI) | 68 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Winona Lake
Compare lakeside cabins, hotels, and vacation rentals near Winona Lake in Douglas County, Minnesota — 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Winona Lake are listed below.
Top-rated places to stay near Winona Lake
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 Minnesota’s top lakes →
Water Temperature
Winona Lake typically sits around 74°F at the surface in August. Summer average is about 75°F. Usually warmest in Jul (about 78°F) and coldest in Oct (about 52°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 199 field readings (2010–2025) via the EPA Water Quality Portal. See the full Winona Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 9 ft |
| Average Depth | 5 ft |
| Surface Area | 213 acres |
| Shoreline Length | 5.4 mi |
| Littoral Zone | 100% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Winona Lake
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2021-06-28 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Bullhead | 150.46 | 0.29 lb |
| Common Carp | 99.42 | 2.6 lb |
| Yellow Perch | 34.31 | 0.18 lb |
| White Sucker | 32.10 | 1.32 lb |
| Black Crappie | 30.11 | 0.21 lb |
| Green Sunfish | 8.60 | 0.12 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Black Bullhead
Common Carp
Yellow Perch
White Sucker
From the 2021-06-28 survey
This nearshore survey was conducted during summer 2021 to assess populations of non-game species and small game fish using backpack electrofishing and seining. Backpack electrofishing and/or seining were conducted at 10 stations, representing a variety of habitat types, along the shoreline of Lake Winona. The survey…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Winona Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — WinonaFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — WinonaFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — WinonaPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.05 m/yr | 4 |
| Phosphorus | ↑ Improving | -15.2 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -11.15 µg/L/yr | 4 |
Ice Season
Historical ice data from Minnesota DNR (24 observations).
Estimated open water season: 221 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2016-03-15 (2016) | 2008-04-22 (2008) |
| Ice-In | 2002-10-27 (2002) | 2001-11-28 (2001) |
Most recent ice-out: 2019-04-15
EPA Impairment Status
Winona Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN21-0081-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Winona Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Alexandria Lakes Area Sanitary DistrictAlexandria · 1 mi away · NPDES MN0040738MajorRecent 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 #37 of 37 lakes in Douglas County
Nearby Lakes With Higher Grades
Winona Lake holds Grade F. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Douglas County
Frequently asked questions about Winona Lake
What is the water quality grade for Winona Lake?
- Winona Lake in Douglas County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 2 ft visibility. Phosphorus: 88 µg/L. Chlorophyll-a (algae): 48.5 µg/L. Maximum depth: 9 ft. Surface area: 213.31 acres.
Is Winona Lake safe to swim in?
- Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Winona Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 48.5 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Winona Lake?
- Winona Lake typically sits around 74°F at the surface in August, from 199 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Winona Lake?
- Winona Lake has a maximum depth of 9 feet and an average depth of 5 feet. The lake covers 213.31 acres.
What fish are in Winona Lake?
- Fish species found in Winona Lake include black bullhead, black crappie, bluegill, brown bullhead, common carp, green sunfish, largemouth bass, walleye, white sucker, yellow bullhead, yellow perch. Winona Lake is located in Douglas County, Minnesota.
When does Winona Lake thaw?
- Winona Lake typically has ice-out around Apr 10. Ice typically forms around Nov 17. The open water season is approximately 221 days.
Explore Winona Lake across LakeGrade
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Where this data comes from
228 measurements from 2 monitoring stations, 2022–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA228 samples · 2022–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (2)
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate