Alabama Lake Water Quality

Alabama lists 422 lakes across 67 counties, 90 of them with a recent water-quality reading. Most of that sampling flows through monitoring run by the Alabama Department of Environmental Management, which feeds state, federal, and volunteer measurements into the EPA Water Quality Portal. The remainder are here because they are real named lakes, not because anyone has sampled them recently. Measured Alabama lakes sit mostly in the middle of the nutrient range, with the highest phosphorus and algae readings in counties where row-crop agriculture dominates the watershed.

By surface area the largest lake here is Yate Lake, at about 40,000 acres, and 44 of the lakes in this index cover more than 500 acres. Size is worth knowing before you go: a large deep basin buffers nutrient inputs by sheer volume, while a shallow one warms quickly and can turn over its whole water column in a single summer storm. The measured lakes lean eutrophic, with enough nutrient input to support an active algal community and the trade-offs in clarity and dissolved oxygen that come with it. The county with the lowest nutrient and algae readings on average is Houston. The gap between counties is large enough that a single figure for Alabama lake water quality hides real local variation.