Alaska Lake Water Quality

Across Alaska, 5 lakes carry an active water-quality grade spread over 4 counties. The underlying measurements come from the Alaska Department of Environmental Conservation, alongside federal programs and volunteer monitoring networks. A-grade lakes are scarce in Alaska: about 0% of the dataset. Most lakes here sit in C or D — productive, often shallow, frequently algal in late summer.

The state's dominant trophic class is oligotrophic: clear, nutrient-poor, slow-growing. These lakes are also the most sensitive to disturbance — the same volume that buffers them against nutrients also slows recovery if those nutrients arrive in quantity. a leading county ranks highest on average county grade (—). a struggling county sits lowest. With only 4 counties in the state, the cross-county spread is narrower than the within-county spread for most lakes.