Hornbean Lake
Hornbean Lake in Dakota County, Minnesota has a water quality grade of C (Fair). Water clarity: 7.2 ft visibility. Phosphorus: 36 µg/L. Chlorophyll-a (algae): 5.6 µg/L.
- Clarity
- 7.2 ft
- Typical in August
- 77°F
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- No
Next lake in Dakota County
Hornbean Lake is a productive, nutrient-rich eutrophic lake in Dakota County, Minnesota. Water quality is graded C based on 2 sampling years through 2024. 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 44 other monitored lakes in Dakota County, Hornbean Lake ranks #21 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-18. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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 7.2 ft. Phosphorus level: 36 µg/L. Chlorophyll-a: 5.6 µg/L. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.2 ft | Not graded |
| Phosphorus | 36 µg/L | Fair |
| Chlorophyll-a (Algae) | 5.6 µg/L | Good |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Hornbean Lake
Compare lakeside cabins, hotels, and vacation rentals near Hornbean Lake in Dakota 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 Hornbean Lake
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Water Temperature
Hornbean Lake typically sits around 77°F at the surface in August. Summer average is about 77°F. Usually warmest in Jul (about 83°F) and coldest in Apr (about 55°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 21 field readings (2019–2024) via the EPA Water Quality Portal. See the full Hornbean Lake water temperature breakdown →
Fishing Hornbean 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.
Source: USGS Nonindigenous Aquatic Species (NAS) Database. Hover a chip to see scientific name, ecological context, status, and first-observed year.
Water Quality Trend: ↓ Declining
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.338 m/yr | 3 |
| Phosphorus | ↓ Declining | +3.13 µg/L/yr | 3 |
| Chlorophyll-a | ↓ Declining | +0.88 µg/L/yr | 3 |
County Ranking
Ranked #21 of 45 lakes in Dakota County
Nearby Lakes With Higher Grades
Hornbean Lake holds Grade C. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Dakota County
Frequently asked questions about Hornbean Lake
What is the water quality grade for Hornbean Lake?
- Hornbean Lake in Dakota County, Minnesota has a water quality grade of C (Fair). Water clarity: 7.2 ft visibility. Phosphorus: 36 µg/L. Chlorophyll-a (algae): 5.6 µg/L.
Is Hornbean Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Hornbean Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 5.6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Hornbean Lake?
- Hornbean Lake typically sits around 77°F at the surface in August, from 21 EPA Water Quality Portal field readings (2019–2024). That is a typical value for the month, not a live reading.
Explore Hornbean 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 Hornbean Lake
Other Grade C Lakes in Minnesota
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Where this data comes from
52 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA52 samples · 2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
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.