St. Mary Parish County Lake Quality

Only 6 lakes in St. Mary Parish County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. 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 Lake Palourde East of Morgan City (D); the most-stressed is Lake Palourde East-Northeast of Berwick (F).