What is the cleanest lake near Lake St. Louis Nr. Hwy 40?

Lake 37 in St. Charles County holds a Grade B water quality score and is 5.3 miles from Lake St. Louis Nr. Hwy 40.

Why is Lake St. Louis Nr. Hwy 40 not Grade A?

Lake St. Louis Nr. Hwy 40 holds Grade F, with about 1 ft of water clarity and 125.8 µg/L of phosphorus. The grade reflects measured water quality against Metropolitan Council thresholds. Cleaner alternatives nearby score higher on clarity, phosphorus, or chlorophyll-a.

Are these recommendations based on real data?

Yes. Every grade is calculated from EPA Water Quality Portal samples for the lake. Recommendations are limited to lakes within 30 miles of Lake St. Louis Nr. Hwy 40 in Wisconsin, with strictly higher numeric grade scores and sufficient monitoring data.

Cleaner Lakes Than Lake St. Louis Nr. Hwy 40, Top 5 Within 30 Miles, LakeQuality

Cleaner Lakes Than Lake St. Louis Nr. Hwy 40

5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.

Lake St. Louis Nr. Hwy 40 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, 5.3 mi away) is the closest meaningful upgrade.

Lake 37

St. Charles County, Wisconsin · 5.3 mi from Lake St. Louis Nr. Hwy 40

+Two grade letters higher (F → B)
++3 ft water clarity
+Lower phosphorus (16 vs 125.8 µg/L)

L. Ste. Louise Lake

St. Charles County, Wisconsin · 0.7 mi from Lake St. Louis Nr. Hwy 40

+Higher grade (F → D)
++1.6 ft water clarity
+Lower phosphorus (40.8 vs 125.8 µg/L)

L. Ste. Louise Lake

St. Charles County, Wisconsin · 0.9 mi from Lake St. Louis Nr. Hwy 40

+Higher grade (F → D)
++2.2 ft water clarity
+Lower phosphorus (33.5 vs 125.8 µg/L)

Lake 36

St. Charles County, Wisconsin · 6.8 mi from Lake St. Louis Nr. Hwy 40

+Higher grade (F → D)
++1.5 ft water clarity
+Lower phosphorus (31 vs 125.8 µg/L)

Lake St. Louis

St. Charles County, Wisconsin · 2 mi from Lake St. Louis Nr. Hwy 40

+Higher grade (F → D)
++1.7 ft water clarity
+Lower phosphorus (50 vs 125.8 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.