Black Oak Lake
Black Oak Lake in Stearns County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 10 ft visibility. Maximum depth: 19 ft. Surface area: 95.09 acres.
- Clarity
- 10 ft
- Typical in August
- 75°F
- Max depth
- 19 ft
- Area
- 95 acres
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Stearns County
Why Black Oak 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 Black Oak 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.
Black Oak Lake is a 95-acre lake in Stearns County, Minnesota with a maximum depth of 19 feet (11-foot average). Overall water quality is improving over recent sampling years. The lake supports 9 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-03. 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 Black Oak Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 10 ft. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Black Oak Lake
Compare lakeside cabins, hotels, and vacation rentals near Black Oak Lake in Stearns 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 Black Oak Lake
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Water Temperature
Black Oak Lake typically sits around 75°F at the surface in August. Summer average is about 72°F. Usually warmest in Aug (about 75°F) and coldest in Apr (about 44°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 34 field readings (2010–2025) via the EPA Water Quality Portal. See the full Black Oak Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 19 ft |
| Average Depth | 11 ft |
| Surface Area | 95 acres |
| Shoreline Length | 3.4 mi |
| Littoral Zone | 103% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Black Oak LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Black Oak Lake
DNR Fisheries Survey Summary
3 surveys on file from MN DNR Fisheries. Most recent: 2019-06-10 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 44.04 | 0.07 lb |
| Black Crappie | 23.32 | 0.17 lb |
| Largemouth Bass | 10.99 | 1.81 lb |
| Northern Pike | 6.49 | 3.66 lb |
| Pumpkinseed | 5.07 | 0.05 lb |
| Green Sunfish | 4.38 | 0.12 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
Largemouth Bass
Northern Pike
From the 2019-06-10 survey
Black Oak Lake is a 119 acre lake located 3 miles south of Melrose in northwestern Stearns County. It has a maximum depth of 19 feet and is classified as Lake Class 42. The watershed (960 acres) is small and mostly row crops (39%) with some forest (28%) and pasture (14%). The DNR owns a public access on the southeast…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Black Oak Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Black OakFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Black Oak (1986)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Black OakFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Black OakPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.299 m/yr | 6 |
EPA Impairment Status
Black Oak 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 MN73-0241-00 · Official waterbody report
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Black Oak Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Melrose WwtpMelrose · 3.5 mi away · NPDES MN0020290MajorRecent violation
- GemsdGreenwald · 2.6 mi away · NPDES MN0056863
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.
Graded lakes near Black Oak Lake
Black Oak Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Stearns County
Frequently asked questions about Black Oak Lake
What is the water quality grade for Black Oak Lake?
- Black Oak Lake in Stearns County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 10 ft visibility. Maximum depth: 19 ft. Surface area: 95.09 acres.
Is Black Oak Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Black Oak Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Black Oak Lake?
- Black Oak Lake typically sits around 75°F at the surface in August, from 34 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Black Oak Lake?
- Black Oak Lake has a maximum depth of 19 feet and an average depth of 11 feet. The lake covers 95.09 acres.
What fish are in Black Oak Lake?
- Fish species found in Black Oak Lake include black bullhead, black crappie, bluegill, common carp, northern pike, pumpkinseed, walleye, white sucker, yellow perch. Black Oak Lake is located in Stearns County, Minnesota.
Are there boat ramps on Black Oak Lake?
- Black Oak Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Black Oak Lake. Public access is listed as yes.
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Where this data comes from
65 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA65 samples · 2020–2025
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory