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LakeQuality

Phelps Lake

F
Grade F — Algae-prone
Algae-prone · #14 of 14 lakes in the county · 2.3 ft clear · Hypereutrophic · 303 acres
Limited DataHypereutrophic

Phelps Lake in Rice County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 2.3 ft visibility. Phosphorus: 334.5 µg/L. Chlorophyll-a (algae): 102.5 µg/L. Maximum depth: 8 ft. Surface area: 303.23 acres.

Clarity
2.3 ft
Max depth
8 ft
Area
303 acres
Type
Hypereutrophic
Public access
Yes
Ice-out
Mar 27

Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Phelps Lake

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FCody Lake2 ft clear · Rice CountyView →
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Phelps Lake is a 303-acre highly nutrient-loaded hypereutrophic lake in Rice County, Minnesota with a maximum depth of 8 feet. Water quality is graded F based on 2 sampling years through 2025. Limited fish-species data available. Public access is available. Compared to the 13 other monitored lakes in Rice County, Phelps Lake ranks #14 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-10. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Limited data

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom

Compare the safest swimming lakes near Mankato

Get alerts for Phelps Lake

Water Quality Grade: F (Algae-prone)

Very murky, less than 2.3 ft of visibility. Phosphorus level: 334.5 µg/L. Chlorophyll-a: 102.5 µg/L. Trophic State Index: 76.

MetricValueGrade
Water Clarity (Secchi Depth)2.3 ftNot graded
Phosphorus334.5 µg/LPoor
Chlorophyll-a (Algae)102.5 µg/LPoor
Trophic State Index (TSI)76Hypereutrophic

Very high nutrients, dense algae, poor clarity

Where to stay near Phelps Lake

Compare lakeside cabins, hotels, and vacation rentals near Phelps Lake in Rice 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Phelps Lake are listed below.

Top-rated places to stay near Phelps 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 →

Lake Details

CharacteristicValue
Maximum Depth8 ft
Surface Area303 acres
Shoreline Length3 mi
Littoral Zone100%
Public AccessYes

Fishing Phelps Lake

Ice Season

Historical ice data from Minnesota DNR (16 observations).

Typical Ice-Out
Mar 27
EarliestLatest
Ice-Out2024-03-02 (2024)2018-04-29 (2018)
Ice-In2024-11-27 (2024)2025-11-28 (2025)

Most recent ice-out: 2026-03-26

EPA Impairment Status

Phelps Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Nutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN66-0062-00 · Official waterbody report

Regulated Pollution Sources Nearby

2 EPA-permitted facilities operate within about 5 miles of Phelps Lake under Clean Water Act (NPDES) discharge permits.

  • Seneca Foods Corp - Montgomery
    Montgomery · 4 mi away · NPDES MN0001279
  • Montgomery Wwtf
    Montgomery · 4 mi away · NPDES MN0024210

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.

County Ranking

Ranked #14 of 14 lakes in Rice County

Nearby Lakes With Higher Grades

Phelps Lake holds Grade F. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

Nearby Lakes in Rice County

Frequently asked questions about Phelps Lake

What is the water quality grade for Phelps Lake?

Phelps Lake in Rice County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 2.3 ft visibility. Phosphorus: 334.5 µg/L. Chlorophyll-a (algae): 102.5 µg/L. Maximum depth: 8 ft. Surface area: 303.23 acres.

Is Phelps Lake safe to swim in?

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Phelps Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 102.5 µg/L. Always check local health department advisories before swimming.

How deep is Phelps Lake?

Phelps Lake has a maximum depth of 8 feet. The lake covers 303.23 acres.

When does Phelps Lake thaw?

Phelps Lake typically has ice-out around Mar 27.

Where this data comes from

19 measurements from 1 monitoring station, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA19 samples · 2025

Analytical methods

  • Field measurement/observation, generic method
  • Total Phosphorus After Block Digestion
  • Analysis of Chlorophyll in Periphyton and Plankton
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

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