Porcupine Lake-Deep Hole

Porcupine Lake-Deep Hole carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. Of the three parameters, phosphorus is the worst — at 54 µg/L of phosphorus, it keeps the lake susceptible to algal blooms in warm years.

A TSI near 48 places Porcupine Lake-Deep Hole in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. 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 57 of 66 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.