Rabour Lake

On the scoring rubric Rabour Lake grades a D: clarity at 3.0 ft and 54 µg/L of phosphorus keep it in the lower bracket for Chisago County. Secchi readings are the weakest of the scored parameters, suggesting suspended sediment or algal biomass dominates the optical signal.

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. Rabour Lake reaches 43 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. Rabour Lake is small — 53 acres alongside 1.3 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Chisago County's 31 graded lakes, Rabour Lake ranks 23 — below the local median, though not at the bottom.

Rabour Lake carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. The fishery includes walleye among the lake's 5 documented species — a notable draw for Minnesota anglers. A documented public access point at Rabour Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been logged at Rabour Lake more than two dozen times, putting the median around Apr 7 — a useful baseline for tracking climate trends. The grade is supported by multiple sampling years from Minnesota PCA volunteers and partner agencies, giving the letter a reasonably stable foundation.