1
BLake 37
St. Charles County, Wisconsin · 6.2 mi from Lake St. Louis by Dam
- +Two grade letters higher (F → B)
- ++1.7 ft water clarity
- +Lower phosphorus (16 vs 74.8 µg/L)
Cleaner Lakes Than Lake St. Louis by Dam
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Lake St. Louis by Dam carries a Grade F (Very Poor) water quality score. Within 30 miles, 5 lakes hold a higher grade. Lake 37 (St. Charles County, Grade B, 6.2 mi away) is the closest meaningful upgrade.
2
DL. Ste. Louise Lake
St. Charles County, Wisconsin · 1.4 mi from Lake St. Louis by Dam
- +Higher grade (F → D)
- +Lower phosphorus (33.5 vs 74.8 µg/L)
3
DL. Ste. Louise Lake
St. Charles County, Wisconsin · 1.9 mi from Lake St. Louis by Dam
- +Higher grade (F → D)
- +Lower phosphorus (40.8 vs 74.8 µg/L)
4
DLake 36
St. Charles County, Wisconsin · 6.7 mi from Lake St. Louis by Dam
- +Higher grade (F → D)
- +Lower phosphorus (31 vs 74.8 µg/L)
5
DLake St. Louis
St. Charles County, Wisconsin · 0.1 mi from Lake St. Louis by Dam
- +Higher grade (F → D)
- +Lower phosphorus (50 vs 74.8 µg/L)
How this list is built
Every lake on LakeQuality has a calculated grade from EPA Water Quality Portal samples — secchi depth, total phosphorus, and chlorophyll-a measured against Metropolitan Council thresholds. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.