Johnson Lake
Johnson Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11 ft visibility. Maximum depth: 24 ft. Surface area: 35.83 acres.
- Clarity
- 11 ft
- Max depth
- 24 ft
- Area
- 36 acres
- Trend
- ↓ Declining
- Public access
- No
- Ice-out
- May 2
- Open water
- 199 days
Next lake in Lake County
Why Johnson Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Johnson Lake, 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. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Johnson Lake is a 36-acre lake in Lake County, Minnesota with a maximum depth of 24 feet. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including smallmouth bass, walleye, and white sucker. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-08. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Johnson Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 11 ft. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Johnson Lake
Compare lakeside cabins, hotels, and vacation rentals near Johnson Lake in Lake 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.
Top-rated places to stay near Johnson Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 24 ft |
| Surface Area | 36 acres |
| Shoreline Length | 1.3 mi |
| Littoral Zone | 59% |
| Public Access | No |
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 Johnson Lake
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2009-07-28 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Yellow Perch | 55.83 | 0.23 lb |
| White Sucker | 43.60 | 1.59 lb |
| Walleye | 17.25 | 1.01 lb |
| Smallmouth Bass | 4.15 | 0.3 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.
Yellow Perch
White Sucker
Walleye
Smallmouth Bass
From the 2009-07-28 survey
Johnson is a 30.5 acre lake with a maximum depth of 24 feet and 18.1 acres (59%) of littoral area. Located about 3.5 miles southeast of Finland, MN, Johnson Lake is completely on property owned by the Wolf Ridge Environmental Learning Center (ELC). The simplistic fish community consists of: walleye, white sucker,…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Johnson Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — JohnsonFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Johnson (0652)Aquatic Plant Report · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.229 m/yr | 4 |
Ice Season
Historical ice data from Minnesota DNR (82 observations).
Estimated open water season: 199 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-04-02 (2012) | 2013-05-16 (2013) |
| Ice-In | 1988-10-28 (1988) | 2016-12-09 (2016) |
Most recent ice-out: 2025-05-04
EPA Impairment Status
Johnson 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 MN38-0242-00 · Official waterbody report
Graded lakes near Johnson Lake
Johnson Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Lake County
Frequently asked questions about Johnson Lake
What is the water quality grade for Johnson Lake?
- Johnson Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11 ft visibility. Maximum depth: 24 ft. Surface area: 35.83 acres.
Is Johnson Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Johnson Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Johnson Lake?
- Johnson Lake has a maximum depth of 24 feet. The lake covers 35.83 acres.
What fish are in Johnson Lake?
- Fish species found in Johnson Lake include smallmouth bass, walleye, white sucker, yellow perch. Johnson Lake is located in Lake County, Minnesota.
When does Johnson Lake thaw?
- Johnson Lake typically has ice-out around May 2. Ice typically forms around Nov 17. The open water season is approximately 199 days.
Explore Johnson Lake across LakeGrade
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Where this data comes from
29 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA29 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate