Skip to main content
LakeQuality
D

Big Stone Lake

Big Stone County, MinnesotaEutrophic

Big Stone Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Minnesota average. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Big Stone Lake ranks 4 of 9 in Big Stone County — solidly in the upper half of the local distribution.

No invasive species are currently listed at Big Stone Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Big Stone Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-08-09. Grade methodology: LakeGrade methodology.

Reviewed by LakeQuality Editorial Team · Updated

Track Big Stone Lake

Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.

Swimming Safety

Swimming not recommended, poor water quality with high algae risk

Water Quality Grade: D, Poor

Murky, only visible to about 3.9 ft. Phosphorus level: 217 µg/L. Trophic State Index: 70.

MetricValueGrade
Water Clarity (Secchi Depth)3.9 ftD
Phosphorus217 µg/LF
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)70Eutrophic

High nutrients, frequent algae, reduced clarity

Location

Loading map…

County Ranking

Ranked #4 of 9 lakes in Big Stone County

Cleaner Lakes Within 30 Miles

Big Stone Lake holds Grade D. One nearby lake has a higher grade.

See full comparison →

Nearby Lakes in Big Stone County

State Parks Near Big Stone Lake

EPA Impairment Status

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

Causes of impairment

MercuryNutrients (phosphorus, nitrogen)

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

Source: EPA ATTAINS assessment unit MN06-0152-00 · Official waterbody report

Data Sources

Water quality data from the EPA Water Quality Portal

Impairment status from EPA ATTAINS 303(d) database

Grading methodology based on Metropolitan Council standards

Most recent sample: 2023-08-09

Monitoring stations: 4