Is Nelson Lake Safe for Swimming?
Nelson Lake in Oliver County, North Dakota has a water quality grade of C (Fair). Swim with caution, moderate algae may be present. Water clarity: 1.3 ft visibility. Phosphorus: 275 µg/L. Chlorophyll-a (algae): 23.1 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | C (Fair) |
| Water Clarity (Secchi Depth) | 1.3 ft |
| Phosphorus | 275 μg/L |
| Chlorophyll-a (Algae) | 23.1 μg/L |
| Location | Oliver County, North Dakota |
How does Nelson Lake compare?
With an overall water quality grade of C, Nelson Lake matches or beats the North Dakota state average of Grade C. It ranks #2 of 3 lakes in Oliver County by water quality score.
Water clarity (Secchi depth) sits at 1.3 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 23.1 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.
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