San Miguel County Lake Quality

San Miguel County holds 9 monitored lakes. With a sample that small the county-level summary describes those specific waters, not necessarily every water body in the county. 1 of those lake carry an A–F grade. The county-level summary describes that subset, not every water body listed. On average, San Miguel County lakes grade an A. That puts it near the top of the New Mexico county ranking.

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. Conchas Reservoir (A) is the cleanest in the county.