Skip to main content
LakeQuality
A

Saganaga Lake

Cook County, MinnesotaOligotrophic

Saganaga Lake earns an A — every scored parameter (clarity and phosphorus) rates among the best monitored waters in Cook County. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. 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. Saganaga Lake ranks 34 of 128 in Cook County — solidly in the upper half of the local distribution.

Saganaga Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Saganaga 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 2024-09-17. Grade methodology: LakeGrade methodology.

Reviewed by LakeQuality Editorial Team · Updated

Track Saganaga Lake

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

Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Good clarity, visible to about 12 ft. Phosphorus level: 7 µg/L. Trophic State Index: 37.

MetricValueGrade
Water Clarity (Secchi Depth)12 ftB
Phosphorus7 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)37Oligotrophic

Low nutrients, clear water, excellent for swimming

Location

Loading map…

County Ranking

Ranked #34 of 128 lakes in Cook County

Nearby Lakes in Cook County

EPA Impairment Status

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

Causes of impairment

Mercury

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

Source: EPA ATTAINS assessment unit MN16-0633-00 · Official waterbody report · Matched by proximity (0.88 km)

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: 2024-09-17

Monitoring stations: 5