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Sycamore Lake carries a Grade F (Algae-prone) water quality score. Within 30 miles, 2 lakes hold a higher grade. Lake Johnson (Wake County, Grade D, 7.2 mi away) is the closest meaningful upgrade.

Reviewed by LakeQuality Editorial Team · Updated
1
D

Lake Johnson

Wake County, North Carolina · 7.2 mi from Sycamore Lake
  • +Higher grade (F → D)
  • +Lower phosphorus (40 vs 50 µg/L)
2
D

Lake Raleigh

Wake County, North Carolina · 7.9 mi from Sycamore Lake
  • +Higher grade (F → D)

Reading the cohort

Only 2 lakes within a 30-mile radius score better than Sycamore Lake's Grade F. 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.

Lake Johnson (Wake County, Grade D) is the closest cleaner option at 7.2 miles from Sycamore 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 Sycamore Lake is on the way to other plans.

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.

How this list is built

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.