Koma Lake
Lake County, MinnesotaLimited DataEutrophic
Koma Lake earns a D — measurements through 2024 show persistent nutrient pressure that limits clarity through the summer.
At a TSI of 54, Koma Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. At only 14 ft deep, Koma Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. Koma Lake covers 250 acres alongside 5.9 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 142 graded lakes of Lake County, Koma Lake sits at rank 138, near the bottom of the county list.
Koma Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Walleye are documented at Koma Lake, one of 8 fish species on record for the lake. No formal public access is documented at Koma Lake — most use is by shoreline residents and their guests. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-07-31. Grade methodology: LakeGrade methodology.
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Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Murky, only visible to about 5 ft. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 14 ft |
| Surface Area | 250.09 acres |
| Shoreline Length | 5.9 mi |
| Littoral Zone | 100% |
| Public Access | No |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Koma Lake (14-day solunar calendar)
→ Is it safe to eat fish from Koma Lake? (mercury & PFAS guide)
→ Koma Lake fishing regulations (limits, seasons, special rules)
Location
County Ranking
Ranked #138 of 142 lakes in Lake County
Nearby Lakes in Lake County
More Minnesota Lake Rankings
Other Grade D Lakes in Minnesota
Eutrophic Lakes in Minnesota
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 2013-07-26 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Walleye | 7.83 | 0.58 lb |
| White Sucker | 7.33 | 2.5 lb |
| LKW | 6.00 | 1.71 lb |
| Northern Pike | 1.00 | 2.31 lb |
| Yellow Perch | 1.00 | 0.12 lb |
| Rock Bass | 0.67 | 0.37 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.
Walleye
White Sucker
LKW
Northern Pike
From the 2013-07-26 survey
Koma Lake is 250 acres and has a maximum depth of 15.5 feet. The lake is located over 20 miles northeast of Isabella, Minnesota and entirely within the Boundary Waters Canoe Area and Wilderness. The lake is accessible via 2 portage routes. The first access being a series of three portages (24 rods, 48 rods, and 129…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Koma Lake. 1 report on file.
- —Fisheries Lake Survey — KomaFisheries Lake Survey · MN DNR LakeFinder
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2024-07-31
Monitoring stations: 1