Gabbro Lake
Gabbro Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4.3 ft visibility. Maximum depth: 50 ft. Surface area: 976.77 acres.
- Clarity
- 4.3 ft
- Max depth
- 50 ft
- Area
- 977 acres
- Public access
- No
Next lake in Lake County
Why Gabbro 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 Gabbro Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). 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.
Gabbro Lake is a 977-acre lake in Lake County, Minnesota with a maximum depth of 50 feet. The lake supports 8 documented fish species including black crappie, northern pike, and rock bass. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-06-14. 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 Gabbro Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Murky, only visible to about 4.3 ft. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.3 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Gabbro Lake
Compare lakeside cabins, hotels, and vacation rentals near Gabbro 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 Gabbro Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 50 ft |
| Surface Area | 977 acres |
| Shoreline Length | 23.7 mi |
| Littoral Zone | 47% |
| Public Access | No |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Gabbro Lake
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2025-07-29 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Tullibee (Cisco) | 12.00 | 0.42 lb |
| Walleye | 7.00 | 0.81 lb |
| Yellow Perch | 3.92 | 0.24 lb |
| White Sucker | 3.13 | 1.42 lb |
| Northern Pike | 2.29 | 3.66 lb |
| Rock Bass | 1.62 | 0.4 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)
Walleye
Yellow Perch
White Sucker
From the 2025-07-29 survey
Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Gabbro Lake on July 29th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Gabbro Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — GabbroFisheries Lake Survey · MN DNR LakeFinder
EPA Impairment Status
Gabbro 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 MN38-0701-00 · Official waterbody report
Graded lakes near Gabbro Lake
Gabbro Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Lake County
Frequently asked questions about Gabbro Lake
What is the water quality grade for Gabbro Lake?
- Gabbro Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4.3 ft visibility. Maximum depth: 50 ft. Surface area: 976.77 acres.
Is Gabbro Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Gabbro 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 Gabbro Lake?
- Gabbro Lake has a maximum depth of 50 feet. The lake covers 976.77 acres.
What fish are in Gabbro Lake?
- Fish species found in Gabbro Lake include black crappie, northern pike, rock bass, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow perch. Gabbro Lake is located in Lake County, Minnesota.
Explore Gabbro Lake across LakeGrade
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Where this data comes from
1 measurement from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA1 sample · 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