Halfmoon Lake
Halfmoon Lake in Wabasha County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.1 ft visibility.
- Clarity
- 5.1 ft
- Typical in August
- 69°F
- Public access
- Yes
Next lake in Wabasha County
Why Halfmoon 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 Halfmoon 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.
Halfmoon Lake is a lake in Wabasha County, Minnesota. Limited fish-species data available. Public access is available with 7 public boat landings.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-10-04. 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 Halfmoon Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Murky, only visible to about 5.1 ft. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.1 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Halfmoon Lake
Compare lakeside cabins, hotels, and vacation rentals near Halfmoon Lake in Wabasha 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 Halfmoon Lake
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Water Temperature
Halfmoon Lake typically sits around 69°F at the surface in August. Summer average is about 72°F. Usually warmest in Jul (about 75°F) and coldest in Sep (about 68°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 9 field readings (2023–2023) via the EPA Water Quality Portal. See the full Halfmoon Lake water temperature breakdown →
Recreation & Access
- Belvidere SloughPublic
- Upper Spring LakePublic
- 10th StreetPublic
- Prichard LakePublic
- Halfmoon LandingPublic
- MinneiskaPublic
Showing 6 of 7 documented landings from the USGS National Boat Ramps inventory.
Fishing Halfmoon Lake
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Halfmoon Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Waumandee Sanitary District #1Waumandee · 4.5 mi away · NPDES WI0061646Recent violation
- Affordable Septic StorageBuffalo City · 2.4 mi away · NPDES WI0065854
- Village Of CochraneCochrane, Village Of · 3.7 mi away · NPDES WI0020214
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 Halfmoon Lake
Halfmoon Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Wabasha County
Frequently asked questions about Halfmoon Lake
What is the water quality grade for Halfmoon Lake?
- Halfmoon Lake in Wabasha County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.1 ft visibility.
Is Halfmoon Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Halfmoon 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 Halfmoon Lake?
- Halfmoon Lake typically sits around 69°F at the surface in August, from 9 EPA Water Quality Portal field readings (2023–2023). That is a typical value for the month, not a live reading.
Are there boat ramps on Halfmoon Lake?
- Halfmoon Lake has 7 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Belvidere Slough, Upper Spring Lake, 10th Street, Prichard Lake, among others. Public access is listed as yes.
Explore Halfmoon Lake across LakeGrade
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Where this data comes from
5 measurements from 1 monitoring station, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA5 samples · 2023
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Named boat-access points from the USGS National Boat Ramps inventory