How Clean Is St. Croix Lake?
St. Croix 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): 8.7 ft. Trophic State Index: 46.
Cleanliness Snapshot
| Metric | St. Croix Lake | Minnesota avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 8.7 ft | — |
| Trophic State Index | 46 | <50 = clean |
How does St. Croix Lake compare?
St. Croix Lake's grade of C matches or beats the Minnesota state average of C. It ranks #19 of 31 lakes in Washington County by water quality score.