Toisnot Reservoir
- +Higher grade (F → D)
- +Lower phosphorus (90 vs 100 µg/L)

2 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Lake Wilson carries a Grade F (Algae-prone) water quality score. Within 30 miles, 2 lakes hold a higher grade. Toisnot Reservoir (Wilson County, Grade D, 3.1 mi away) is the closest meaningful upgrade.
Within 30 miles of Lake Wilson, 2 lakes score higher on EPA water-quality metrics than its Grade F. The short list means the alternatives are real upgrades but not interchangeable — each carries its own access, size, and species mix worth checking before substituting it into a weekend plan.
The closest cleaner alternative — Toisnot Reservoir in Wilson County, Grade D — sits 3.1 miles from Lake Wilson. 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 Toisnot Reservoir is mostly a habit change rather than a logistics change.
Lakes are graded A to F on nutrients and algae — total phosphorus, total nitrogen, chlorophyll-a, and turbidity — measured against the EPA National Lakes Assessment 2022 condition classes for that lake's own ecoregion, so a lake is judged against the lakes it would naturally resemble. A higher letter reflects measurably lower nutrient and algae levels, 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. The full grading formula is on our methodology page.
Rated lakes on LakeQuality have a letter from EPA Water Quality Portal samples — nutrients and algae measured against EPA National Lakes Assessment ecoregion classes. Secchi is shown, not scored. 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.