Marion-Mill Dam Lake
- +Two grade letters higher (D → A)
- ++10 ft water clarity
- +Lower phosphorus (9 vs 68 µg/L)
4 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Marion-Charles Lake carries a Grade D (Poor) water quality score. Within 30 miles, 4 lakes hold a higher grade. Marion-Mill Dam Lake (Marion County, Grade A, 5.4 mi away) is the closest meaningful upgrade.
4 cleaner lakes sit within 30 miles of Marion-Charles Lake in the EPA water-quality dataset. With that many higher-grade neighbors close by, Marion-Charles Lake's Grade D reflects something specific to the lake itself — not a regional water-quality ceiling. The neighbor list below isn't a small set of marginal upgrades; it's a real cohort of meaningfully cleaner choices for the same Florida weekend.
Marion-Mill Dam Lake (Marion County, Grade A) is the closest cleaner option at 5.4 miles from Marion-Charles 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 Marion-Charles 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.
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.