Sierra County Lake Quality

Sierra County has 9 monitored lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. The 9 monitored lakes in Sierra County carry whatever clarity, phosphorus, and chlorophyll-a readings SWRCB has published, shown as reported.

Most of the county's monitored lakes are shallow, under 50 feet, which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed.