Saint Johns Lake
Kandiyohi County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Saint Johns Lake. Here is what has been measured.
- Impaired · Nutrients (phosphorus, nitrogen)
- 35 ft max depth
- Limited data
Saint Johns Lake in Kandiyohi County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 0.5 ft visibility. Phosphorus: 189 µg/L. Chlorophyll-a (algae): 140 µg/L.
Saint Johns Lake is a lake in Kandiyohi County, Minnesota with an estimated average depth of about 35 feet. Overall water quality is improving 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 2023-09-12. Methodology: how these readings are compared.
What Saint Johns Lake is good for
From access and monitoring records, not editorial picks.
- Ice seasonIce-out around Apr 7
Swimming conditions
No readingRecreation use not supported
Nutrient and algae readings are not a swimming clearance. Saint Johns Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Saint Johns 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 Saint Johns Lake
These are the measurements Minnesota PCA publishes for Saint Johns Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 0.5 ft of visibility. Phosphorus 189 µg/L. Chlorophyll-a 140 µg/L. TSI 82.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 0.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 189µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 140µg/L | Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water. |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 82 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Saint Johns Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Saint Johns Lake typically sits around 58°F at the surface in September. Summer average is about 75°F. Usually warmest in Jul (about 81°F) and coldest in Sep (about 58°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (58°F) to its warmest (81°F).
Typical surface water temperature by month, from 32 field readings (2010–2023) via the EPA Water Quality Portal. See the full Saint Johns Lake water temperature breakdown →
Lake Details
Max depth
~35 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 Saint Johns Lake.
Lake Size & Watershed
Watershed (drainage) area
25 sq mi
HydroLAKES / HydroSHEDS
Surface area
166 acres
HydroLAKES / HydroSHEDS
Shoreline
1.9 mi
HydroLAKES / HydroSHEDS
Elevation
1,112 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 Saint Johns Lake
Compare lakeside cabins, hotels, and vacation rentals near Saint Johns Lake in Kandiyohi 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 Saint Johns Lake
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Fishing Saint Johns Lake
Water Quality Trend: Improving
Based on 4 years of monitoring (2020–2023).
Water clarity
Improving4 years
Ice season
Typical ice-out
Apr 7
Earliest Mar 21, 2021 · Latest Apr 30, 2013
Typical ice-in
Nov 20
Earliest Nov 17, 2006 · Latest Nov 22, 2007
Most recent ice-out
Apr 12
2022
11 observations · Minnesota PCA ice records
EPA Impairment Status
Saint Johns Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN34-0283-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Saint Johns Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger.
- Willmar WwtpWillmar · 3.8 mi away · NPDES MN0025259Major
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 Kandiyohi County
Frequently asked questions about Saint Johns Lake
Where is Saint Johns Lake?
- Saint Johns Lake is a lake in Kandiyohi County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Saint Johns Lake?
- Saint Johns Lake in Kandiyohi County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 0.5 ft visibility. Phosphorus: 189 µg/L. Chlorophyll-a (algae): 140 µg/L.
Is Saint Johns Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Saint Johns Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Saint Johns Lake?
- Saint Johns Lake typically sits around 58°F at the surface in September, from 32 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
How deep is Saint Johns Lake?
- No published bathymetric survey covers Saint Johns Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 35 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 Saint Johns Lake thaw?
- Saint Johns Lake typically has ice-out around Apr 7. Ice typically forms around Nov 20. The open water season is approximately 227 days.
Can I fish at Saint Johns Lake?
- Public access to Saint Johns 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.
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Where this data comes from
25 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA25 samples · 2020–2023
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)
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
Impairment status from EPA ATTAINS 303(d) database
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