Broadwater Bay Lake

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

Mesotrophic conditions dominate at Broadwater Bay Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake's 54 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. At 5,520 acres, Broadwater Bay Lake is one of the larger lakes in Cass County, with 30.3 miles of shoreline supporting multiple distinct use patterns. Broadwater Bay Lake sits at rank 67 of 133 in Cass County, in the lower half of the local distribution.

Zebra mussels have been documented at Broadwater Bay Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Broadwater Bay Lake's fishery is anchored by muskellunge, with 22 documented species in total — a destination water for muskie anglers. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a long ice-out record — 28 observations on file, with a median ice-out around Apr 24. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.