Diamond Lake

On the LakeGrade scale Diamond Lake grades a B, with clarity at 12.5 ft and 25 µg/L of phosphorus placing it above the Wisconsin median. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. The lake bottoms out at 17 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Diamond Lake covers 117 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Oneida County's 140 graded lakes, Diamond Lake ranks 101 — below the local median, though not at the bottom.

Diamond Lake has no invasive species recorded in Wisconsin state databases as of 2020, though prevention practices still apply at all access points. The fishery includes walleye alongside the lake's other 5 documented species — a notable draw for Wisconsin anglers. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.