Winona Lake
Winona Lake in Winona County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 2.6 ft visibility. Phosphorus: 51.5 µg/L. Chlorophyll-a (algae): 33.3 µg/L. Maximum depth: 38 ft. Surface area: 308.43 acres.
- Clarity
- 2.6 ft
- Max depth
- 38 ft
- Area
- 308 acres
- Type
- Eutrophic
- Public access
- Yes
- Ice-out
- Mar 30
- Open water
- 244 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 Winona County
Winona Lake is a 308-acre productive, nutrient-rich eutrophic lake in Winona County, Minnesota with a maximum depth of 38 feet. Water quality is graded F based on 2 sampling years through 2021. The lake supports 24 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 8 public boat landings.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-09-29. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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 2.6 ft of visibility. Phosphorus level: 51.5 µg/L. Chlorophyll-a: 33.3 µg/L. Trophic State Index: 63.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.6 ft | Not graded |
| Phosphorus | 51.5 µg/L | Poor |
| Chlorophyll-a (Algae) | 33.3 µg/L | Poor |
| Trophic State Index (TSI) | 63 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Winona Lake
Compare lakeside cabins, hotels, and vacation rentals near Winona Lake in Winona 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
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Planning a trip? Cabins and lodging at Winona Lake → · more Minnesota lake trips
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 38 ft |
| Surface Area | 308 acres |
| Shoreline Length | 5.2 mi |
| Littoral Zone | 90% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Mertes SloughPublic
- East 5th StreetPublic
- Latsch Isand ParkPublic
- Lake WinonaPublic
- Winona Municipal HarborPublic
- The PointPublic
Showing 6 of 8 documented landings from the USGS National Boat Ramps inventory.
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Winona Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
22 surveys on file from MN DNR Fisheries. Most recent: 2021-07-12 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 39.05 | 0.14 lb |
| Largemouth Bass | 37.10 | 1.37 lb |
| Black Crappie | 12.94 | 0.24 lb |
| GIS | 9.40 | 0.72 lb |
| Yellow Perch | 4.31 | 0.16 lb |
| Black Bullhead | 3.18 | 0.63 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.
Bluegill
Largemouth Bass
Black Crappie
GIS
From the 2021-07-12 survey
The 318 acre Lake Winona is located in the City of Winona and is surrounded by city park and biking path. There are two distinct basins to the lake. The upper (West) basin is generally shallow with little depth diversity, while the lower (East) basin has more depth and habitat diversity. A dredging project completed…
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
Ice Season
Historical ice data from Minnesota DNR (11 observations).
Estimated open water season: 244 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2026-03-13 (2026) | 1989-04-08 (1989) |
| Ice-In | 1991-11-05 (1991) | 1982-12-07 (1982) |
Most recent ice-out: 2026-03-13
EPA Impairment Status
Winona Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN85-0011-01 · Official waterbody report · Matched by proximity (0.76 km)
Regulated Pollution Sources Nearby
5 EPA-permitted facilities operate within about 5 miles of Winona Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 2 facilities have a reported Clean Water Act violation in the past three years.
- Winona WwtpWinona · 2.2 mi away · NPDES MN0030147MajorRecent violation
- Peerless Chain CoWinona · 1.9 mi away · NPDES MN0001325Recent violation
- Rtp CoWinona · 1.4 mi away · NPDES MN0053350
- Cytec Engineered Materials IncWinona · 2.3 mi away · NPDES MN0003441
- Uscoe Lock & Dam 5A WtpWinona · 3.6 mi away · NPDES MN0068870
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 #1 of 1 lakes in Winona County
Nearby Lakes With Higher Grades
Winona Lake holds Grade F. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Winona County
Frequently asked questions about Winona Lake
What is the water quality grade for Winona Lake?
- Winona Lake in Winona County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 2.6 ft visibility. Phosphorus: 51.5 µg/L. Chlorophyll-a (algae): 33.3 µg/L. Maximum depth: 38 ft. Surface area: 308.43 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 33.3 µg/L. Always check local health department advisories before swimming.
How deep is Winona Lake?
- Winona Lake has a maximum depth of 38 feet. The lake covers 308.43 acres.
What fish are in Winona Lake?
- Fish species found in Winona Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, freshwater drum, gizzard shad, green sunfish, hybrid sunfish, largemouth bass, longnose gar, mooneye, northern pike, pumpkinseed, shortnose gar, smallmouth bass, smallmouth buffalo, walleye, warmouth, white bass, white crappie, yellow bullhead, yellow perch. Winona Lake is located in Winona County, Minnesota.
When does Winona Lake thaw?
- Winona Lake typically has ice-out around Mar 30. Ice typically forms around Nov 29. The open water season is approximately 244 days.
Are there boat ramps on Winona Lake?
- Winona Lake has 8 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Mertes Slough, East 5th Street, Latsch Isand Park, Lake Winona, among others. Public access is listed as yes.
Explore Winona Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Minnesota
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Winona Lake
Other Grade F Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
30 measurements from 2 monitoring stations, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA30 samples · 2021
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate