Winona Lake
Kosciusko County, IndianaView mapDirections
Not Rated: one monitoring station are on record, but they measured water clarity only. LakeQuality’s A–F method grades total phosphorus, total nitrogen, chlorophyll-a, and turbidity; clarity is shown, not scored.
- Impaired · PCBs
- 48 ft max depth
- Limited data
Winona Lake in Kosciusko County, Indiana is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2.8 ft visibility.
- Clarity
- 2.8 ft
- Max depth
- ~48 ft est.
- Trend
- ↑ Improving
Stays via Stay22
Stays near Winona Lake
Compare lakeside cabins, hotels, and vacation rentals near Winona Lake in Kosciusko County, Indiana — 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 Winona Lake
Prices for Sep 11–13, 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 Indiana’s top lakes →
Watch Winona Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Why Winona Lake has no grade
Winona Lake has monitoring on record from one station, but only water clarity was measured. LakeQuality’s A–F letter uses total phosphorus, total nitrogen, chlorophyll-a, and turbidity against EPA National Lakes Assessment condition classes. With none of those grading measurements on record, Winona Lake is Not Rated — not an F. Its 2.8-foot median from 11 readings collected 2021 is still shown as clarity, but clarity alone cannot earn a letter.
Not Rated is EPA Integrated Reporting Category 3 — insufficient information. Everything below that has been measured is still reported on this page.
Sampling is run by IDEM and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Winona Lake is a lake in Kosciusko County, Indiana with an estimated average depth of about 48 feet. Overall water quality is improving over recent sampling years.
Source: EPA Water Quality Portal sampling records, IDEM, last sampled 2021-08-09. Grade methodology: LakeQuality methodology.
Swimming Safety
Not ratedBacteria F
Based on E. coli testing, Winona Lake routinely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 29.2% of 24 samples across 3 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Indiana’s current beach and health-department advisories before swimming.
Water quality measurements for Winona Lake
These readings exist but are not enough for an A–F grade — see why.
Very murky, less than 2.8 ft of visibility. TSI 62.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.8 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 62 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~48 ft est. |
| Average Depth | ~11 ft est. |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Indiana has not published bathymetry for Winona Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Winona Lake
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.125 m/yr | 3 |
| Phosphorus | ↑ Improving | -44.19 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +3.55 µg/L/yr | 2 |
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
Source: EPA ATTAINS assessment unit INB06P1007_00 · Official waterbody report
Regulated Pollution Sources Nearby
19 EPA-permitted facilities operate within about 5 miles of Winona Lake under Clean Water Act (NPDES) discharge permits.
- Winona Lake Municipal WwtpWinona Lake · 0.5 mi away · NPDES IN0024881
- Crystal Lake Egg Products IncWarsaw · 0.7 mi away · NPDES IN0046191
- Associated Milk Producers IncWarsaw · 0.9 mi away · NPDES IN0001554
- Grace College Residence HallWinona Lake · 0.9 mi away · NPDES INR10K711
- Grace College Athletic Track And FieldWinona Lake · 1.2 mi away · NPDES INR10L867
- Lake City Greenway - Park Avenue To Grace CollegeWinona Lake · 1.2 mi away · NPDES INR10H036
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 Kosciusko County
Frequently asked questions about Winona Lake
Where is Winona Lake?
- Winona Lake is a lake in Kosciusko County, Indiana. LakeQuality has not rated this lake (UNRATED) — the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity.
What is the water quality grade for Winona Lake?
- Winona Lake in Kosciusko County, Indiana is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2.8 ft visibility.
Is Winona Lake safe to swim in?
- Based on E. coli testing, Winona Lake routinely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 29.2% of 24 samples across 3 seasons. That works out to a bacteria swim-safety grade of F — a historical summary of past testing, not a current reading. Winona Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Bacteria levels can spike quickly after heavy rain, so always check Indiana's current beach and health-department advisories before you swim.
How deep is Winona Lake?
- No published bathymetric survey covers Winona Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 48 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Winona Lake across LakeQuality
Species activity outlook by water temperature and season
Top lakes and where to stay in the Northern Indiana Lake Country area
Where to stay at Indiana's top lakes, each with its grade
Indiana's cleanest and most-polluted lakes, ranked
More Indiana Lake Rankings
Other Lakes in Indiana
Eutrophic Lakes in Indiana
Where this data comes from
11 measurements from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North American Lake Management Society
NALMS11 samples · 2021
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)