Pirz Lake
Stearns County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Pirz Lake. Here is what has been measured.
- Mesotrophic
- 38 ft max depth
Pirz Lake in Stearns County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 12 ft visibility. Phosphorus: 26 µg/L. Chlorophyll-a (algae): 6.1 µg/L.
Pirz Lake is a mesotrophic lake in Stearns County, Minnesota with an estimated average depth of about 38 feet. 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 31 other monitored lakes in Stearns County, Pirz Lake ranks #8 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-15. Methodology: how these readings are compared.
What Pirz Lake is good for
From access and monitoring records, not editorial picks.
- Clear water12 ft of visibility
- Ice seasonIce-out around Apr 9
Swimming conditions
Readings onlyModerate algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Pirz Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Pirz Lake
These are the measurements Minnesota PCA publishes for Pirz Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 12 ft. Phosphorus 26 µg/L. Chlorophyll-a 6.1 µg/L. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 26µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 6.1µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Pirz Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Pirz Lake typically sits around 59°F at the surface in September. Summer average is about 66°F. Usually warmest in Aug (about 68°F) and coldest in May (about 53°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (53°F) to its warmest (68°F).
Typical surface water temperature by month, from 113 field readings (2010–2021) via the EPA Water Quality Portal. See the full Pirz Lake water temperature breakdown →
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Pirz Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fish Stocking History — PirzFish Stocking History · MN DNR LakeFinder
Lake Details
Max depth
~38 ft est.
Public access
No
Listed by Minnesota PCA
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Pirz Lake.
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Surface area
64 acres
HydroLAKES / HydroSHEDS
Shoreline
1.9 mi
HydroLAKES / HydroSHEDS
Elevation
1,125 ft
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.
Stays via Stay22
Stays near Pirz Lake
Compare lakeside cabins, hotels, and vacation rentals near Pirz Lake in Stearns 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 Pirz Lake
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Fishing Pirz Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Worsening+1.63 µg/L/yr6 years
Chlorophyll-a
Stable-0.21 µg/L/yr6 years
Ice season
Typical ice-out
Apr 9
Earliest Mar 15, 2016 · Latest Apr 30, 2018
Typical ice-in
Dec 1
Earliest Nov 30, 2006 · Latest Dec 9, 2017
Most recent ice-out
Apr 30
2018
8 observations · Minnesota PCA ice records
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Pirz Lake under Clean Water Act (NPDES) discharge permits.
- Paul Magedanz Farm 1Richmond · 1.3 mi away · NPDES MN0069841
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.
Nearby Lakes in Stearns County
Frequently asked questions about Pirz Lake
Where is Pirz Lake?
- Pirz Lake is a lake in Stearns County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Pirz Lake?
- Pirz Lake in Stearns County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 12 ft visibility. Phosphorus: 26 µg/L. Chlorophyll-a (algae): 6.1 µg/L.
Is Pirz Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Pirz Lake?
- Pirz Lake typically sits around 59°F at the surface in September, from 113 EPA Water Quality Portal field readings (2010–2021). That is a typical value for the month, not a live reading.
How deep is Pirz Lake?
- No published bathymetric survey covers Pirz Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 38 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
When does Pirz Lake thaw?
- Pirz Lake typically has ice-out around Apr 9. Ice typically forms around Dec 1. The open water season is approximately 236 days.
Can I fish at Pirz Lake?
- Public access to Pirz Lake is listed as no on the lake record, so confirm before you make the trip. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Pirz Lake across LakeQuality
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Where this data comes from
104 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA104 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate