Lake St. Croix vs St. Croix 0.3 Mi. Downstream of I Lake
Water quality, depth, fish species, and recreation comparison.
Lake St. Croix has a higher water quality grade (B, Good) than St. Croix 0.3 Mi. Downstream of I Lake (C, Fair).
Lake St. Croix is in Wisconsin; St. Croix 0.3 Mi. Downstream of I Lake is in Minnesota. Cross-state comparisons carry an extra wrinkle — Minnesota PCA and Wisconsin DNR use slightly different sampling cadences and station coverage, though both feed the same EPA Water Quality Portal. The grades are close: Lake St. Croix (B) and St. Croix 0.3 Mi. Downstream of I Lake (C) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.
With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Lake St. Croix
Murky, only visible to about 5.6 ft.
St. Croix 0.3 Mi. Downstream of I Lake
Murky, only visible to about 6.1 ft.
Side-by-Side Metrics
| Metric | Lake St. Croix | St. Croix 0.3 Mi. Downstream of I Lake |
|---|---|---|
| Overall Grade | B (Good) | C (Fair) |
| Water Clarity | 5.6 ft | 6.1 ft |
| Phosphorus | 16.5 µg/L | 34 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 60 ft | 78 ft |
| Surface Area | 7.7K acres | 8.4K acres |
| Public Access | Unknown | No |
| Fish Species | 0 | 1 |
| Trophic State | mesotrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Lake St. Croix wins on overall water quality with a Grade B versus St. Croix 0.3 Mi. Downstream of I Lake's Grade C. Water clarity: 5.6 ft vs 6.1 ft. For more fish-species variety, St. Croix 0.3 Mi. Downstream of I Lake edges ahead with 1 documented species.