Twenty-One Lake
- +Higher grade (B → A)
- ++7.5 ft water clarity
- +Lower phosphorus (10 vs 17.5 µg/L)
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Garfield Lake carries a Grade B (Good) water quality score. Within 30 miles, 5 lakes hold a higher grade. Twenty-One Lake (Hubbard County, Grade A, null mi away) is the closest meaningful upgrade.
Within 30 miles of Garfield Lake, 5 water bodies score higher than its Grade B on the same EPA water-quality metrics. That density of cleaner options is itself a signal — when several nearby lakes score better on the same indicators, the issues at Garfield Lake are typically lake-specific (depth, watershed inflow, stratification pattern) rather than regional. The choice for a swim, paddle, or fishing trip is genuinely between meaningfully different water bodies, not between marginal differences in the same dataset.
The closest cleaner alternative — Twenty-One Lake in Hubbard County, Grade A — sits miles from Garfield 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 Twenty-One 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.
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.