Saganaga Lake
Saganaga Lake in Cook County, Minnesota has a water quality grade of A (Excellent). Water clarity: 13 ft visibility. Phosphorus: 7 µg/L. Chlorophyll-a (algae): 2.9 µg/L.
- Clarity
- 13 ft
- Type
- Oligotrophic
- Trend
- ↑ Improving
Next lake in Cook County
Saganaga Lake is a cold, clear oligotrophic lake in Cook County, Minnesota. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. Compared to the 43 other monitored lakes in Cook County, Saganaga Lake ranks #28 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-16. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLow algae
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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Good clarity, visible to about 13 ft. Phosphorus level: 7 µg/L. Chlorophyll-a: 2.9 µg/L. Trophic State Index: 38.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 13 ft | Not graded |
| Phosphorus | 7 µg/L | Good |
| Chlorophyll-a (Algae) | 2.9 µg/L | Good |
| Trophic State Index (TSI) | 38 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Saganaga Lake
Compare lakeside cabins, hotels, and vacation rentals near Saganaga Lake in Cook 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.
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Fishing Saganaga Lake
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.225 m/yr | 2 |
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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN16-0633-00 · Official waterbody report · Matched by proximity (1.48 km)
County Ranking
Ranked #28 of 44 lakes in Cook County
Nearby Lakes in Cook County
Frequently asked questions about Saganaga Lake
What is the water quality grade for Saganaga Lake?
- Saganaga Lake in Cook County, Minnesota has a water quality grade of A (Excellent). Water clarity: 13 ft visibility. Phosphorus: 7 µg/L. Chlorophyll-a (algae): 2.9 µg/L.
Is Saganaga Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Saganaga Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 2.9 µg/L. Always check local health department advisories before swimming.
Explore Saganaga Lake across LakeGrade
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Where this data comes from
65 measurements from 6 monitoring stations, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA65 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (6)
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