St. John the Baptist Parish County Lake Quality

There are 23 graded lakes in St. John the Baptist Parish County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. The county average is F — the most-stressed bracket in our rubric. Most monitored lakes here show persistent nutrient loading and algal pressure.

The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Lac des Allemands Southwest of Killona Lake (F); the most-stressed is Lac des Allemands Southwest of Killona Lake (F).