Dewey County Lake Quality

Dewey County holds 11 monitored lakes. With a sample that small the county-level summary describes those specific waters, not necessarily every water body in the county. No lake in Dewey County has enough sampling behind it for an A–F grade yet. The 11 monitored lakes below carry whatever clarity, phosphorus, and chlorophyll-a measurements exist.

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.