Cleaner Lakes Than Cascade R Lake

Reading the cohort

Within 30 miles of Cascade R Lake, 5 water bodies score higher than its Grade C 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 Cascade R 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.

Cascade Reservoir A Sugar Loaf Island (Valley County, Grade B) is the closest cleaner option at 12.4 miles from Cascade R Lake — close enough to be a genuine substitute for most users, far enough that it isn't the same neighborhood lake. Worth the trip if water quality is the primary driver; less obvious if Cascade R Lake is on the way to other plans.

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.