Ima Lake
Ima 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: 116 ft. Surface area: 741.91 acres.
- Clarity
- 11 ft
- Max depth
- 116 ft
- Area
- 742 acres
- Trend
- ↓ Declining
- Public access
- No
Next lake in Lake County
Why Ima 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 Ima 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.
Ima Lake is a 742-acre lake in Lake County, Minnesota with a maximum depth of 116 feet. Overall water quality is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-08-31. 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 Ima 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 Ima Lake
Compare lakeside cabins, hotels, and vacation rentals near Ima 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 Ima Lake
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Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Ima Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (34,995 cells/mL) on April 25, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 116 ft |
| Surface Area | 742 acres |
| Shoreline Length | 14.9 mi |
| Littoral Zone | 28% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fishing Ima Lake
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 2025-08-19 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Tullibee (Cisco) | 14.75 | 0.27 lb |
| Lake Trout | 3.81 | 1.98 lb |
| Walleye | 3.00 | 2.69 lb |
| Northern Pike | 2.58 | 2.68 lb |
| White Sucker | 2.44 | 1.41 lb |
| Yellow Perch | 1.08 | 0.1 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.
Tullibee (Cisco)
Lake Trout
Walleye
Northern Pike
From the 2025-08-19 survey
Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Ima Lake on August 19th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake (Cisco, also known as…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Ima Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — ImaFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.081 m/yr | 5 |
EPA Impairment Status
Ima 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 MN38-0400-00 · Official waterbody report
Nearby Lakes in Lake County
Frequently asked questions about Ima Lake
What is the water quality grade for Ima Lake?
- Ima 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: 116 ft. Surface area: 741.91 acres.
Is Ima Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Ima 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 Ima Lake?
- Ima Lake has a maximum depth of 116 feet. The lake covers 741.91 acres.
Does Ima Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Ima Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (34,995 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Explore Ima Lake across LakeGrade
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Where this data comes from
43 measurements from 16 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA43 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (16)
- MNPCA-38-0400-00-100
- MNPCA-38-0400-00-217
- MNPCA-38-0400-00-209
- MNPCA-38-0400-00-214
- MNPCA-38-0400-00-220
- MNPCA-38-0400-00-204
- MNPCA-38-0400-00-216
- MNPCA-38-0400-00-208
- MNPCA-38-0400-00-212
- MNPCA-38-0400-00-203
- MNPCA-38-0400-00-213
- MNPCA-38-0400-00-201
- MNPCA-38-0400-00-211
- MNPCA-38-0400-00-210
- MNPCA-38-0400-00-219
- MNPCA-38-0400-00-206
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