How Clean Is Lake St. Croix?
Lake St. Croix 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): 5.2 ft. Phosphorus: 18 µg/L. Trophic State Index: 50.
Cleanliness Snapshot
| Metric | Lake St. Croix | Minnesota avg |
|---|---|---|
| Overall Grade | B | C |
| Water Clarity (Secchi) | 5.2 ft | — |
| Phosphorus | 18 µg/L | <30 = clean |
| Trophic State Index | 50 | <50 = clean |
How does Lake St. Croix compare?
Lake St. Croix's grade of B matches or beats the Minnesota state average of C. It ranks #9 of 31 lakes in Washington County by water quality score.