How Clean Is Big Portage (W Bay Lake?
Big Portage (W Bay Lake is a clean lake by Minnesota standards. It received a water quality grade of B (Good) based on EPA monitoring data. Water clarity (Secchi depth): 7.5 ft. Phosphorus: 20 µg/L. Trophic State Index: 48.
Cleanliness Snapshot
| Metric | Big Portage (W Bay Lake | Minnesota avg |
|---|---|---|
| Overall Grade | B | C |
| Water Clarity (Secchi) | 7.5 ft | — |
| Phosphorus | 20 µg/L | <30 = clean |
| Trophic State Index | 48 | <50 = clean |
How does Big Portage (W Bay Lake compare?
Big Portage (W Bay Lake's grade of B matches or beats the Minnesota state average of C. It ranks #118 of 133 lakes in Cass County by water quality score. Multi-year monitoring data shows water quality is improving based on 5 years of records.