Ballantyne Lake

On the LakeGrade rubric Ballantyne Lake fails the cutoffs — a TSI of 67 and persistent algal pressure put it in the bottom tier. 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 in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. The lake's 58 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. Ballantyne Lake covers 371 acres alongside 3.7 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Blue Earth County's 9 graded lakes, Ballantyne Lake ranks 5 — below the local median, though not at the bottom.

Ballantyne Lake carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. The fishery includes walleye alongside the lake's other 16 documented species — a notable draw for Minnesota anglers. A documented public access point at Ballantyne 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.