What is the cleanest lake near Harriet Lake?

Wolfe Park Lake in Hennepin County holds a Grade C water quality score and is null miles from Harriet Lake.

Why is Harriet Lake not Grade A?

Harriet Lake holds Grade D, with about 9.7 ft of water clarity and 190.5 µg/L of phosphorus. The grade reflects measured water quality against Metropolitan Council thresholds. Cleaner alternatives nearby score higher on clarity, phosphorus, or chlorophyll-a.

Are these recommendations based on real data?

Yes. Every grade is calculated from EPA Water Quality Portal samples for the lake. Recommendations are limited to lakes within 30 miles of Harriet Lake in Minnesota, with strictly higher numeric grade scores and sufficient monitoring data.

Cleaner Lakes Than Harriet Lake, Top 3 Within 30 Miles, LakeQuality

Cleaner Lakes Than Harriet Lake

3 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.

Harriet Lake carries a Grade D (Poor) water quality score. Within 30 miles, 3 lakes hold a higher grade. Wolfe Park Lake (Hennepin County, Grade C, null mi away) is the closest meaningful upgrade.

Wolfe Park Lake

Hennepin County, Minnesota · mi from Harriet Lake

+Higher grade (D → C)
+Lower phosphorus (59.5 vs 190.5 µg/L)

Bde Maka Ska Lake

Hennepin County, Minnesota · mi from Harriet Lake

+Higher grade (D → C)
+Lower phosphorus (88 vs 190.5 µg/L)

Lake of the Isles

Hennepin County, Minnesota · mi from Harriet Lake

+Higher grade (D → C)
+Lower phosphorus (53 vs 190.5 µg/L)

Reading the cohort

Only 3 lakes within a 30-mile radius score better than Harriet Lake's Grade D. The narrow set of options reflects either a fairly clean lake to begin with or a region without a wide range of cleaner alternatives — the trip-planning decision is more constrained than the headline "cleaner lakes nearby" suggests.

The closest cleaner alternative — Wolfe Park Lake in Hennepin County, Grade C — sits miles from Harriet Lake. At that distance, the substitution cost is essentially zero: same drive time, same regional access, demonstrably cleaner water on the EPA indicators. For repeat visitors who care about clarity or phosphorus levels, swapping the routine to Wolfe Park Lake is mostly a habit change rather than a logistics change.

The EPA water-quality grading combines clarity (Secchi depth), phosphorus, and chlorophyll-a measurements from state environmental sampling. A higher letter grade reflects measurably cleaner water on those indicators, not subjective beauty or access quality — a Grade A lake might have worse boat-launch facilities or shoreline access than a Grade C neighbor, so the ranking is one input alongside the rest of trip planning. See the methodology page for the full grading formula.

How this list is built

Every lake on LakeQuality has a calculated grade from EPA Water Quality Portal samples — secchi depth, total phosphorus, and chlorophyll-a measured against Metropolitan Council thresholds. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.