North Twin Lake

North Twin Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Polk County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Trophically, North Twin Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. A maximum depth of 27 ft puts North Twin Lake in the middle of Wisconsin's depth distribution. At 129 acres, North Twin Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Within Polk County's 77 graded waters, North Twin Lake sits at rank 9, near the top of the local distribution.

Eurasian watermilfoil is established at North Twin Lake, which can dampen recreational access and pressure the native plant community. The fishery includes walleye alongside the lake's other 4 documented species — a notable draw for Wisconsin anglers. A documented public access point at North Twin 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.