Kohlman Lake
Kohlman Lake in Ramsey County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.6 ft visibility. Phosphorus: 96 µg/L. Chlorophyll-a (algae): 24 µg/L. Maximum depth: 9 ft. Surface area: 84.11 acres.
- Clarity
- 3.6 ft
- Typical in August
- 73°F
- Max depth
- 9 ft
- Area
- 84 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- No
- Ice-out
- Apr 1
- Open water
- 242 days
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Kohlman Lake →
Next lake in Ramsey County
Kohlman Lake is a 84-acre productive, nutrient-rich eutrophic lake in Ramsey County, Minnesota with a maximum depth of 9 feet. Water quality is graded D based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 11 documented fish species including black bullhead, black crappie, and bluegill. No public access — the lake is private or restricted. Compared to the 43 other monitored lakes in Ramsey County, Kohlman Lake ranks #30 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyAlgae risk
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 3.6 ft. Phosphorus level: 96 µg/L. Chlorophyll-a: 24 µg/L. Trophic State Index: 63.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.6 ft | Not graded |
| Phosphorus | 96 µg/L | Poor |
| Chlorophyll-a (Algae) | 24 µg/L | Poor |
| Trophic State Index (TSI) | 63 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Kohlman Lake
Compare lakeside cabins, hotels, and vacation rentals near Kohlman Lake in Ramsey 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Kohlman Lake are listed below.
Top-rated places to stay near Kohlman Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Kohlman Lake typically sits around 73°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 75°F) and coldest in Jan (about 36°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 564 field readings (2010–2025) via the EPA Water Quality Portal. See the full Kohlman Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 9 ft |
| Surface Area | 84 acres |
| Shoreline Length | 1.8 mi |
| Littoral Zone | 100% |
| 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 Kohlman Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2005-08-08 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 47.81 | 0.15 lb |
| Black Crappie | 10.93 | 0.18 lb |
| White Crappie | 6.18 | 0.24 lb |
| Black Bullhead | 3.03 | 0.65 lb |
| Common Carp | 1.87 | 4.69 lb |
| Largemouth Bass | 1.53 | 0.75 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.
Bluegill
Black Crappie
White Crappie
Black Bullhead
From the 2005-08-08 survey
No active fish management is conducted on Kohlman Lake due to the lack of a public access. The lake is connected to Gervais Lake by a navigable channel with no barriers to fish movement. Although the sample size was small, Walleye were captured above the median level for abundance. Three of the Walleyes captured were…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Kohlman Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — KohlmanFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.113 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.41 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +2.19 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (39 observations).
Estimated open water season: 242 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-03 (2024) | 2018-04-28 (2018) |
| Ice-In | 2019-11-08 (2019) | 2023-12-28 (2023) |
Most recent ice-out: 2026-03-28
EPA Impairment Status
Kohlman 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 MN62-0006-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Kohlman Lake under Clean Water Act (NPDES) discharge permits.
- Hb Fuller Co-Willow LakeVadnais Heights · 0.7 mi away · NPDES MN0051811
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #30 of 44 lakes in Ramsey County
Nearby Lakes With Higher Grades
Kohlman Lake holds Grade D. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Ramsey County
Frequently asked questions about Kohlman Lake
What is the water quality grade for Kohlman Lake?
- Kohlman Lake in Ramsey County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 3.6 ft visibility. Phosphorus: 96 µg/L. Chlorophyll-a (algae): 24 µg/L. Maximum depth: 9 ft. Surface area: 84.11 acres.
Is Kohlman Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Kohlman Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 24 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Kohlman Lake?
- Kohlman Lake typically sits around 73°F at the surface in August, from 564 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Kohlman Lake?
- Kohlman Lake has a maximum depth of 9 feet. The lake covers 84.11 acres.
What fish are in Kohlman Lake?
- Fish species found in Kohlman Lake include black bullhead, black crappie, bluegill, common carp, hybrid sunfish, largemouth bass, tiger muskellunge, walleye, white sucker, yellow bullhead, yellow perch. Kohlman Lake is located in Ramsey County, Minnesota.
When does Kohlman Lake thaw?
- Kohlman Lake typically has ice-out around Apr 1. Ice typically forms around Nov 29. The open water season is approximately 242 days.
Explore Kohlman Lake across LakeGrade
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Where this data comes from
573 measurements from 5 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
MNPCA573 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2130 B ~ Nephelometric Method
- Turbidity, Nephelometric Method
- Turbidity by Nephelometry
Monitoring station identifiers (5)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate