Nevada County Lake Quality

The county-level average smooths over real differences — a single agricultural watershed near the southwest corner can pull the average down even if the rest of the county runs clean. 1 of those lake carry recent nutrient and algae readings. The county-level summary describes that subset, not every water body listed. Most monitored lakes in Nevada County carry favourable nutrient and algae readings for California.

The county's lakes lean shallow, which makes the readings sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest measured lake is Lake Combie.