Arizona Lake Water Quality

Across {{stateName}}, 81 lakes carry an active water-quality grade spread over 14 counties. The underlying measurements come from {{agency}}, alongside federal programs and volunteer monitoring networks. A-grade lakes are scarce in {{stateName}}: about 5% of the dataset. Most lakes here sit in C or D — productive, often shallow, frequently algal in late summer.

Eutrophic conditions dominate — nutrient-loaded, productive, with algal pressure that shows up most years in late summer. These lakes tend to be shallow, agricultural-watershed, and over-warmed by the time July ends. Cochise ranks highest on average county grade (B). Mohave sits lowest. With only 14 counties in the state, the cross-county spread is narrower than the within-county spread for most lakes.