Hannan Lake

Hannan Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

At a TSI of 58, Hannan 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. Within Hennepin County's 104 graded waters, Hannan Lake sits at rank 23, near the top of the local distribution.

No invasive species are currently listed at Hannan Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Hannan Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Hannan Lake — most use is by shoreline residents and their guests. Multiple sampling years from Minnesota PCA volunteers and partner agencies back the grade, so the letter should hold steady absent a major watershed shift.