How Clean Is Nelson Lake?
Nelson Lake has fair water quality — typical of lakes with moderate nutrient enrichment. It received a water quality grade of C (Fair) based on EPA monitoring data. Water clarity (Secchi depth): 5 ft. Phosphorus: 23.9 µg/L. Trophic State Index: 52.
Cleanliness Snapshot
| Metric | Nelson Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 5 ft | — |
| Phosphorus | 23.9 µg/L | <30 = clean |
| Trophic State Index | 52 | <50 = clean |
How does Nelson Lake compare?
Nelson Lake's grade of C matches or beats the Wisconsin state average of C. It ranks #39 of 50 lakes in Sawyer County by water quality score. Multi-year monitoring data shows water quality is declining based on 6 years of records.