Porter Lake
Porter Lake in Blue Earth County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 1.3 ft visibility. Phosphorus: 140 µg/L. Chlorophyll-a (algae): 73 µg/L.
- Clarity
- 1.3 ft
- Mean depth
- ~9 ft est.
- Public access
- No
Next lake in Blue Earth County
Why Porter 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 Porter Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, 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.
Porter Lake is a lake in Blue Earth County, Minnesota with an estimated average depth of about 9 feet. 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 2023-08-02. 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 Porter Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Very murky, less than 1.3 ft of visibility. Phosphorus level: 140 µg/L. Chlorophyll-a: 73 µg/L. Trophic State Index: 74.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.3 ft | Not graded |
| Phosphorus | 140 µg/L | Not graded |
| Chlorophyll-a (Algae) | 73 µg/L | Not graded |
| Trophic State Index (TSI) | 74 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Porter Lake
Compare lakeside cabins, hotels, and vacation rentals near Porter Lake in Blue Earth 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.
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Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~9 ft est. |
| Public Access | No |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Porter Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Porter Lake
Graded lakes near Porter Lake
Porter Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Blue Earth County
Frequently asked questions about Porter Lake
What is the water quality grade for Porter Lake?
- Porter Lake in Blue Earth County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 1.3 ft visibility. Phosphorus: 140 µg/L. Chlorophyll-a (algae): 73 µg/L.
Is Porter Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Porter Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Algae concentration (chlorophyll-a) is 73 µg/L. Always check local health department advisories before swimming.
How deep is Porter Lake?
- No published bathymetric survey covers Porter Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 9 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Porter Lake across LakeGrade
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Where this data comes from
4 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
MNPCA4 samples · 2023
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2120 B ~ Color in Water by Visual Comparison
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder