How Clean Is Big Hollow Lake?
Big Hollow Lake has very poor water quality and a high algae bloom risk. It received a water quality grade of F (Very Poor) based on EPA monitoring data. Water clarity (Secchi depth): 1.8 ft. Chlorophyll-a (algae): 46 µg/L. Trophic State Index: 68.
Cleanliness Snapshot
| Metric | Big Hollow Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | F | D |
| Water Clarity (Secchi) | 1.8 ft | — |
| Chlorophyll-a (Algae) | 46 µg/L | <10 = clean |
| Trophic State Index | 68 | <50 = clean |
How does Big Hollow Lake compare?
Big Hollow Lake's grade of F falls below the Wisconsin state average of D. It ranks #1 of 2 lakes in Des Moines County by water quality score.