Unn Lake
Unn Lake in Hennepin County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar.
- Trend
- ↓ Declining
- Public access
- No
Next lake in Hennepin County
Why Unn 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 Unn Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
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.
Unn Lake is a lake in Hennepin County, Minnesota. Overall water quality is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2020-02-25. Grade methodology: LakeGrade methodology.
Watch Unn Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Unn Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples |
Where to stay near Unn Lake
Compare lakeside cabins, hotels, and vacation rentals near Unn Lake in Hennepin 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 Unn Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Fishing Unn Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.049 m/yr | 5 |
| Phosphorus | → Stable | -0.16 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +1.58 µg/L/yr | 5 |
EPA Impairment Status
Unn 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 MN27-0073-00 · Official waterbody report · Matched by proximity (2.23 km)
Graded lakes near Unn Lake
Unn Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Hennepin County
Frequently asked questions about Unn Lake
What is the water quality grade for Unn Lake?
- Unn Lake in Hennepin County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar.
Is Unn Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Unn Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Explore Unn Lake across LakeGrade
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Hennepin County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Crow River Watershed, ranked by water quality
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Unn Lake
Other Lakes in Minnesota
Where this data comes from
8 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA8 samples · 2020
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