How Clean Is Johanna Lake?
Johanna Lake has fair water quality — typical of lakes with moderate nutrient enrichment. Its nutrient and algae readings come from EPA monitoring data. Water clarity (Secchi depth): 5.1 ft. Phosphorus: 34.5 µg/L. Chlorophyll-a (algae): 13.4 µg/L. Trophic State Index: 55.
Cleanliness Snapshot
| Metric | Johanna Lake | Minnesota avg |
|---|---|---|
| Water Clarity (Secchi) | 5.1 ft | — |
| Phosphorus | 34.5 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 13.4 µg/L | <10 = clean |
| Trophic State Index | 55 | <50 = clean |
How does Johanna Lake compare?
Johanna Lake's readings match or beat the Minnesota state average. It ranks #6 of 20 lakes in Pope County by water quality score. Multi-year monitoring data shows water quality is stable based on 6 years of records.
Watch Johanna Lake water quality
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