Is Alder Lake Safe for Swimming?
Alder Lake in Cook County, Minnesota has limited nutrient and algae sampling on record. A water-quality reading is not a swimming clearance. The state water agency and county health departments post current advisories; check them before you swim.. Water clarity: 13.8 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 3.1 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Water Clarity (Secchi Depth) | 13.8 ft |
| Phosphorus | 8 μg/L |
| Chlorophyll-a (Algae) | 3.1 μg/L |
| Maximum Depth | 72 ft |
| Location | Cook County, Minnesota |
How does Alder Lake compare?
Alder Lake is not rated for water quality — it does not have enough recent summer sampling for a readings, so it is not compared with the Minnesota state average.
Water clarity (Secchi depth) sits at 13.8 feet. That counts as exceptional clarity — sunlight penetrates deep, supporting submerged plants and limiting algae. Algae levels (chlorophyll-a) measure 3.1 µg/L — low and well within safe swimming guidelines.
Watch Alder Lake water quality
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