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LakeQuality

Lake St. Croix vs St. Croix Lake

Water quality, depth, fish species, and recreation comparison.

Lake St. Croix has a higher water quality grade (B, Good) than St. Croix Lake (C, Fair). Both are in Washington County, Minnesota.

Lake St. Croix and St. Croix Lake are both in Minnesota — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. These two are within a letter of each other on the rubric — Lake St. Croix (B) versus St. Croix Lake (C). The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.

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.

B

Lake St. Croix

Washington County, Minnesota

Murky, only visible to about 5.2 ft.

C

St. Croix Lake

Washington County, Minnesota

Moderate clarity, visible to about 8.7 ft.

Side-by-Side Metrics

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

MetricLake St. CroixSt. Croix Lake
Overall GradeB (Good)C (Fair)
Water Clarity5.2 ft8.7 ft
Phosphorus18 µg/LNo data
Chlorophyll-a (Algae)No dataNo data
Maximum Depth78 ft78 ft
Surface Area8.4K acres8.4K acres
Public AccessNoNo
Fish Species11
Trophic Statemesotrophicmesotrophic

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 Lake's Grade C. Water clarity: 5.2 ft vs 8.7 ft. For fishing diversity, Lake St. Croix also leads with 1 species.