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LakeQuality

The single cleanest lake in Georgia is Lake Worth (Dougherty County, GA), with the highest combined water quality score in our 2026 dataset (grade A). Cleanliness is measured by Secchi depth (clarity), total phosphorus, and chlorophyll-a — all sourced from EPA Water Quality Portal and state agency sampling. The full top 25 ranked list appears below.

The "cleanest" ranking on LakeQuality starts from the A–F letter — nutrients and algae scored against EPA National Lakes Assessment 2022 ecoregion classes. Secchi clarity is shown and used only as a tiebreak, not as a graded input. The cleanest Georgia lake on the current data is Lake Worth (Dougherty County, GA) (A).

The top of the cleanest-lakes list is dominated by deep, glacial, cold-water basins — the same basins that produce the A-grade bracket overall. The pattern is not coincidence: depth and watershed land-use are the dominant inputs to water-clarity and nutrient-loading both.

RankLakeCountyGradeClarityPhosphorusChlorophyll-aArea
1Lake Worth (Dougherty County, GA)DoughertyA3.7 ft46.9 µg/L5 µg/L1,400 acres
2Flint River ReservoirDoughertyA4.3 ft30 µg/L4.8 µg/L1,400 acres
3Harl LakeHarrisA6.1 ft13 µg/L5.1 µg/L5,850 acres
4Lake BlackshearCrispB3.9 ft30.5 µg/L12.5 µg/L8,700 acres
5Geoh LakeStewartB3.7 ft31.5 µg/L11.7 µg/L-
6Banks LakeLanierB3.2 ft30 µg/L7.6 µg/L700 acres
7Wesc LakeTroupC6 ft12 µg/L10.7 µg/L-
8Lake OconeeGreeneC5.6 ft20 µg/L12.9 µg/L-
9Lake Blue RidgeFanninC9.5 ft20 µg/L3.8 µg/L3,220 acres
10Lake TobesofkeeBibbC4.7 ft30 µg/L13 µg/L1,756 acres
11Lake Sidney LanierForsythC9.2 ft20 µg/L7.7 µg/L-
12Goat Rock LakeHarrisC5.2 ft20 µg/L5.8 µg/L960 acres
13West Point LakeTroupC7.2 ft20 µg/L11 µg/L25,864 acres
14Lake OliverMuscogeeC6.1 ft20 µg/L6.8 µg/L2,280 acres
15Lake JulietteMonroeC8.5 ft20 µg/L4.2 µg/L3,600 acres
16Lake SinclairBaldwinC4.9 ft25 µg/L12 µg/L15,330 acres
17Carters LakeGilmerC8.1 ft20 µg/L8.4 µg/L3,275 acres
18Lake HardingHarrisC6 ft20 µg/L5 µg/L5,850 acres
19Lake NottelyUnionC8.9 ft20 µg/L6.9 µg/L3,970 acres
20Lake Lanier Upstream From Flowery Branch ConfluenceHallC13 ft20 µg/L6.2 µg/L-
21Lake Walter F. GeorgeQuitmanC4.1 ft34.1 µg/L18 µg/L-
22Lake BurtonRabunC12.5 ft20 µg/L3.4 µg/L2,775 acres
23Lake RabunRabunC10.9 ft20 µg/L3.7 µg/L-
24Clarks Hill LakeColumbiaC7.9 ft20 µg/L5.8 µg/L-
25Clarks Hill LakeLincolnC6.7 ft20 µg/L7.2 µg/L-

Get updates when Georgia's cleanest-lake list changes

New nutrient and algae samples can move a lake up or down this ranking. Unsubscribe anytime.

Clearest lakes in Georgia by water clarity

“Clearest” ranks by Secchi depth — how far you can see into the water — which can differ from the combined cleanliness score above. The clearest water in Georgia is Lake Hartwell at 13.5 ft of Secchi visibility.

  1. 1. Lake Hartwell13.5 ft, Hart County
  2. 2. Lake Lanier Upstream From Flowery Branch Confluence13 ft, Hall County
  3. 3. Lake Burton12.5 ft, Rabun County
  4. 4. Lake Rabun10.9 ft, Rabun County
  5. 5. Lake Blue Ridge9.5 ft, Fannin County
See the full clearest-lakes ranking for Georgia

Frequently Asked Questions

What is the cleanest lake in Georgia?

Lake Worth (Dougherty County, GA) has the highest water quality score in our 2026 Georgia dataset (grade A). 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. Cleanliness here means a low nutrient load and little algae, measured directly from EPA and state DNR samples; where two lakes tie on the letter, the deeper Secchi reading ranks first.

What is the most polluted lake in Georgia?

Among monitored Georgia lakes, Lake Allatoona ranks among the most polluted by combined phosphorus and chlorophyll-a load. See our full ranking on the most-polluted-lakes trend page for state-by-state details.

Where in Georgia has the cleanest water?

Georgia's clearest waters are concentrated in deeper, lower-nutrient glacial basins with forested or low-agriculture watersheds. Among the current top-ranked lakes above, counties like Harris, Dougherty, and Troup produce the highest-scoring lakes.

What is the clearest lake in Georgia?

Lake Hartwell is the clearest lake in Georgia by water clarity, with a Secchi depth of 13.5 feet — the deepest transparency in our 2026 dataset. "Clearest" ranks by Secchi depth (how far you can see into the water) specifically, while "cleanest" combines clarity with phosphorus and chlorophyll-a. See our full clearest-lakes ranking for Georgia for the top 25 by Secchi clarity.

Are these lakes safe to swim in?

Not on the letter alone. An A or B is a nutrients-and-algae classification, not a swimming clearance — it does not measure E. coli, cyanotoxins, or a posted beach closure, and a lake with low chlorophyll-a can still bloom. Always check current posted advisories before swimming: water quality changes seasonally, especially in late summer when blue-green algae bloom risk peaks.

How are these grades calculated?

The letter is nutrients and algae — phosphorus, nitrogen, chlorophyll-a, and turbidity — scored against EPA National Lakes Assessment 2022 condition classes for that lake’s ecoregion, not a Georgia-only 0–100 average and not an equal-weight mean with Secchi. Water clarity is shown; it is not scored. Lakes without enough recent sampling are UNRATED. Our methodology page has the full rubric.

What are the top 5 cleanest lakes in the US?

There is no single national ranking of cleanest lakes — each state agency uses different metrics. Crater Lake (Oregon) is widely cited as the clearest US lake, with Secchi depths over 30 m. Lake Tahoe and Lake Superior are also top-tier nationally. Within Georgia, the 25 lakes ranked above are the graded lakes with the highest letters in our 2026 dataset.

How we rank cleanest lakes

Cleanliness here means three things working together:

  • Secchi clarity — how deep you can see into the water (in feet). Greater depth = clearer water = lower suspended sediment and algae.
  • Total phosphorus — the nutrient that fuels algae. Lower phosphorus levels mean less algae growth potential.
  • Chlorophyll-a — the green pigment in algae. Direct measurement of how much algae is currently in the water.

Each signal is normalized against Georgia state norms and combined into a single 0–100 score. The lakes above are sorted by that combined score.Full methodology →

Where to stay near Georgia's cleanest lakes

Compare cabins, resorts, and rentals around Lake Worth (Dougherty County, GA) and the other lakes in this ranking, with live availability and prices for your trip. Each pin on the map is one of the ranked lakes above.

Top-rated places to stay near Lake Worth (Dougherty County, GA)

Prices for Sep 11–13, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

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Source: EPA National Aquatic Resource Surveys, 2026.