Kidney Lake
Kidney Lake in Cass County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.5 ft visibility. Maximum depth: 55 ft. Surface area: 56.38 acres.
- Clarity
- 11.5 ft
- Max depth
- 55 ft
- Area
- 56 acres
- Trend
- ↑ Improving
- Public access
- No
Next lake in Cass County
Why Kidney 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 Kidney 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.
Kidney Lake is a 56-acre lake in Cass County, Minnesota with a maximum depth of 55 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-10-22. Grade methodology: LakeGrade methodology.
Watch Kidney Lake water quality
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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 Kidney Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 11.5 ft. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Kidney Lake
Compare lakeside cabins, hotels, and vacation rentals near Kidney Lake in Cass 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 Kidney Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 55 ft |
| Surface Area | 56 acres |
| Shoreline Length | 1.6 mi |
| Littoral Zone | 41% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Big Springs ResortSemi-private
Fishing Kidney Lake
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1981-08-11 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 6.25 | 0.14 lb |
| Yellow Perch | 2.67 | 0.12 lb |
| Pumpkinseed | 0.75 | 0.32 lb |
| Northern Pike | 0.67 | 4.62 lb |
| Black Crappie | 0.50 | 0.75 lb |
| White Sucker | 0.33 | 2 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
From the 1981-08-11 survey
Additional Field Notes: Two adult loons sightedPresent Fish Population Status: Test netting indicates a poor population of all species of fish. Local reports indicate fair largemouth bass and black crappie fishing.
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Kidney Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — KidneyFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.455 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.44 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -0.12 µg/L/yr | 6 |
EPA Impairment Status
Kidney 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 MN11-0062-00 · Official waterbody report · Matched by proximity (2.89 km)
Graded lakes near Kidney Lake
Kidney Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Cass County
Frequently asked questions about Kidney Lake
What is the water quality grade for Kidney Lake?
- Kidney Lake in Cass County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.5 ft visibility. Maximum depth: 55 ft. Surface area: 56.38 acres.
Is Kidney Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Kidney 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 Kidney Lake?
- Kidney Lake has a maximum depth of 55 feet. The lake covers 56.38 acres.
Are there boat ramps on Kidney Lake?
- Kidney Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Big Springs Resort. Public access is listed as no on the lake record, so confirm the landing before you trailer a boat.
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Where this data comes from
15 measurements from 1 monitoring station, 2020–2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA15 samples · 2020–2021
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
Named boat-access points from the USGS National Boat Ramps inventory