Round Island Lake
Lake County, Minnesota55 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Round Island Lake. Here is what has been measured.
- Eutrophic
- 4 ft max depth
- Limited data
Round Island Lake in Lake County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Phosphorus: 34 µg/L. Maximum depth: 4 ft. Surface area: 54.82 acres.
Minnesota DNR's Standard Survey on June 27, 1983 caught 0.25 walleye per trap net at Round Island Lake. DNR survey details →
Round Island Lake is a 55-acre productive, nutrient-rich eutrophic lake in Lake County, Minnesota with a maximum depth of 4 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 34 other monitored lakes in Lake County, Round Island Lake ranks #35 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-16. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
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 Round Island 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 Round Island Lake
These are the measurements Minnesota PCA publishes for Round Island Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 34 µg/L. TSI 55.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 34µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | No reading 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. | 55 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Round Island Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Standard Survey on June 27, 1983 caught 0.25 walleye per trap net at Round Island Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Round Island Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1983-06-27 (Standard Survey).
1 survey on file · most recent 1983-06-27 (Standard Survey)
43 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Yellow Perch | 17.25 | 0.14 lb | |
| White Sucker | 2.50 | 0.63 lb | |
| Walleye | 0.25 | 0.1 lb | |
| Northern Pike | 0.25 | 1.5 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
From the 1983-06-27 survey
The fish population is dominated by Yellow Perch, various minnows and White Sucker. Two Northern Pike and one Walleye were sampled. The Walleye is most likely a migrant from Delay Lake.
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Round Island Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Round IslandFisheries Lake Survey · MN DNR LakeFinder
Lake Details
Max depth
4 ft
Surface area
55 acres
Shoreline
1.6 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
2 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,939 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Round Island Lake
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Top-rated places to stay near Round Island Lake
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Fishing Round Island Lake
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Improving-10 µg/L/yr3 years
Nearby Lakes in Lake County
Frequently asked questions about Round Island Lake
Where is Round Island Lake?
- Round Island Lake is a lake in Lake County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Round Island Lake?
- Round Island Lake in Lake County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Phosphorus: 34 µg/L. Maximum depth: 4 ft. Surface area: 54.82 acres.
Is Round Island Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Round Island Lake?
- Round Island Lake has a maximum depth of 4 feet. The lake covers 54.82 acres.
What did the DNR fisheries survey find at Round Island Lake?
- Minnesota DNR's Standard Survey on June 27, 1983 caught 0.25 walleye per trap net at Round Island Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Round Island Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Round Island Lake?
- Public access to Round Island 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
6 measurements from 2 monitoring stations, 2023–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA6 samples · 2023–2025
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- Phosphorus by Colorimetry
- Turbidity by Nephelometry
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder