Otter Lake

On the LakeGrade scale Otter Lake grades a B, with clarity at 11.7 ft and 22 µg/L of phosphorus placing it above the Minnesota median. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI near 45 places Otter Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. The lake bottoms out at 21 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Otter Lake covers 302 acres alongside 4.2 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 49 graded lakes in Ramsey County, Otter Lake ranks 2 — in the top quartile locally.

Eurasian watermilfoil is established at Otter Lake, which can dampen recreational access and pressure the native plant community. Walleye are documented at Otter Lake, one of 12 fish species on record for the lake. A documented public access point at Otter Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a long ice-out record — 32 observations on file, with a median ice-out around Apr 3. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.