Goodwiler Lake

Goodwiler Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. 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.

A TSI near 45 places Goodwiler Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. At 23 acres, Goodwiler Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Among the 6 graded lakes in Iowa County, Goodwiler Lake sits at rank 2, above the county median.

An invasive species record — Curly-Leaf Pondweed — has been logged at Goodwiler Lake; Wisconsin DNR maintains the official infested-waters list. The fishery is bass-led, with 3 documented species across the lake's records. A documented public access point at Goodwiler 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.