Jefferson County Lake Quality

There are 18 monitored lakes in Jefferson County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. 2 of those lakes carry an A–F grade. The county-level summary describes that subset, not every water body listed. On average, Jefferson County lakes grade D, with phosphorus loading and reduced clarity showing up across most of the dataset.

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 Purs Lake (D); the most-stressed is Bvlj Lake (F).