Porcupine Lake-Deep Hole

Porcupine Lake-Deep Hole earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

At a TSI of 56, Porcupine Lake-Deep Hole reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. A maximum depth of 20 ft puts Porcupine Lake-Deep Hole in the middle of Wisconsin's depth distribution. Porcupine Lake-Deep Hole is small — 32 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Porcupine Lake-Deep Hole ranks 56 of 62 in Oconto County — at the lower end of the locally monitored distribution.

Eurasian watermilfoil has been documented at Porcupine Lake-Deep Hole, requiring shoreline management to keep dense mats from crowding native vegetation. The fishery is bass-led, with 3 documented species across the lake's records. 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.