Black Lake
Black Lake in Ramsey County, Minnesota has a water quality grade of C (Fair). Water clarity: 6.9 ft visibility. Phosphorus: 36 µg/L. Chlorophyll-a (algae): 5.3 µg/L.
- Clarity
- 6.9 ft
- Typical in August
- 72°F
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- No
Next lake in Ramsey County
Black Lake is a productive, nutrient-rich eutrophic lake in Ramsey County, Minnesota. Water quality is graded C based on 2 sampling years through 2023. Overall water quality is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 43 other monitored lakes in Ramsey County, Black Lake ranks #15 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-07-11. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Moderate clarity, visible to about 6.9 ft. Phosphorus level: 36 µg/L. Chlorophyll-a: 5.3 µg/L. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.9 ft | Not graded |
| Phosphorus | 36 µg/L | Fair |
| Chlorophyll-a (Algae) | 5.3 µg/L | Good |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Black Lake
Compare lakeside cabins, hotels, and vacation rentals near Black 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.
Top-rated places to stay near Black Lake
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Water Temperature
Black Lake typically sits around 72°F at the surface in August. Summer average is about 72°F. Usually warmest in Jul (about 75°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 35 field readings (2010–2022) via the EPA Water Quality Portal. See the full Black Lake water temperature breakdown →
Fishing Black Lake
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.088 m/yr | 6 |
| Phosphorus | ↓ Declining | +1.34 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +4.38 µg/L/yr | 6 |
EPA Impairment Status
Black 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 MN62-0027-00 · Official waterbody report · Matched by proximity (1.63 km)
County Ranking
Ranked #15 of 44 lakes in Ramsey County
Nearby Lakes With Higher Grades
Black Lake holds Grade C. 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 Black Lake
What is the water quality grade for Black Lake?
- Black Lake in Ramsey County, Minnesota has a water quality grade of C (Fair). Water clarity: 6.9 ft visibility. Phosphorus: 36 µg/L. Chlorophyll-a (algae): 5.3 µg/L.
Is Black Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Black Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 5.3 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Black Lake?
- Black Lake typically sits around 72°F at the surface in August, from 35 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
Explore Black Lake across LakeGrade
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Species activity outlook by water temperature and season
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High nutrients, frequent algae, reduced clarity
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State Parks Near Black Lake
Other Grade C Lakes in Minnesota
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Where this data comes from
80 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA80 samples · 2020–2023
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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