Heron Lake

Heron Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Secchi readings are the weakest of the three parameters, suggesting suspended sediment or algal biomass dominates the optical signal.

At a TSI of 65, Heron Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Among the 7 graded lakes in Jackson County, Heron Lake sits at rank 2, above the county median.

No invasive species are currently listed at Heron Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Heron Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. A documented public access point at Heron Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.