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Updated August 2026 · Top 25 of 112 lakes with a Secchi reading

Clearest Lake in Virginia: Top 25 by Secchi Depth

Coles Run Reservoir in Augusta County is the clearest lake in Virginia by Secchi depth, at 25.8 ft. Mapped and ranked below: the 25 clearest of 112 Virginia lakes with a Secchi reading. Secchi depth is clarity alone: phosphorus and chlorophyll-a are separate readings, so a clear lake can carry higher nutrient readings than a murkier one.

Map · 25 ranked lakesTap a pin for its lakeTap a pin for the lake's page

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Nutrient and algae readings on recordNo reading on record#1 in this rankingPins are this ranking's lakes at their surveyed locations.

How clear are Virginia's clearest lakes?

From 25.8 ft at Coles Run Reservoir to 9.7 ft at #25, Lake Laura; the median of the 25 is 10.5 ft.

#	Lake	County	Secchi depth	Area
1	Coles Run Reservoir	Augusta	25.8 ft	5 acres
2	Lake Robertson	Rockbridge	13.9 ft	26 acres
3	John Flannagan Reservoir	Dickenson	13.1 ft	—
4	Mouth Big Lick Cr. Lake	Alleghany	12.5 ft	—
5	Lower Blackwater River Lake	Franklin	12.1 ft	—
6	Dam Lake	Franklin	12.1 ft	2,880 acres
7	Dam Lake	Alleghany	12.1 ft	2,530 acres
8	North Fork Pound Reservoir	Wise	12.1 ft	154 acres
9	Carvins Cove Reservoir	Botetourt	11.5 ft	569 acres
10	Lake Witten	Tazewell	11.3 ft	62 acres
11	Mouth of Witcher Cr. Lake	Bedford	11.2 ft	—
12	Dam Lake	Pittsylvania	10.5 ft	20,400 acres
13	Cool Branch Lake	Franklin	10.5 ft	—
14	Wise Lake	Wise	10.5 ft	58 acres
15	Goose Point Lake	Franklin	10.2 ft	—
16	Mouth Craddock Cr. Lake	Bedford	10.2 ft	—
17	Mouth of Bull Run Lake	Franklin	10.2 ft	—
18	Motts Run Reservoir	Spotsylvania	10.2 ft	160 acres
19	Cove Lake	Franklin	10.2 ft	—
20	Lake Thoreau	Fairfax	10 ft	40 acres
21	Laurel Bed Lake	Russell	9.8 ft	395 acres
22	Confl. Blackwater River Lake	Bedford	9.8 ft	—
23	Talbott Reservoir	Patrick	9.8 ft	165 acres
24	Horseshoe Point Lake	Patrick	9.8 ft	—
25	Lake Laura	Shenandoah	9.7 ft	44 acres

Sources and method

Secchi depth: Median of each lake's EPA Water Quality Portal readings, sampled April 2012 to July 2026, in feet. For 24 of these 25 lakes the submitting agency is Virginia Department OF Environmental Quality. Portal: EPA Water Quality Portal.
Readings: clarity, phosphorus and chlorophyll-a from the agency's own sampling, shown as reported. Clarity is a separate measurement from nutrients and algae, which is why a clear lake here can carry higher phosphorus than a murkier one.
Area: state agency lake surveys and, for reservoirs, US Army Corps of Engineers National Inventory of Dams records, in acres at normal pool. A dash means no record carries one.
Map pins: all 25 table rows. No other lakes are plotted.

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Frequently Asked Questions

What is the clearest lake in Virginia?

Coles Run Reservoir in Augusta County is the clearest lake in Virginia by Secchi depth, at 25.8 ft. Secchi depth is measured by lowering a black-and-white disk until it disappears from view; a deeper reading means clearer water. Coles Run Reservoir’s phosphorus and chlorophyll-a readings are on its page.

How clear are Virginia's 25 clearest lakes?

They span 9.7 ft to 25.8 ft of Secchi depth, with a median of 10.5 ft. Coles Run Reservoir leads by 11.9 ft. Franklin County has 6 of the 25; the rest are spread across 14 other counties.

How is water clarity measured?

Water clarity is measured by Secchi depth, named after the 19th-century Italian astronomer Pietro Angelo Secchi who developed the method. A standardized black-and-white disk is lowered into the water on a rope; the depth (in feet or meters) at which the disk disappears from view is recorded. Greater Secchi depth means clearer water, usually a sign of low sediment, low phosphorus, and limited algae growth. The figure for each lake here is the median of its readings.

What makes a lake clear?

Lake clarity is driven by three factors: low suspended sediment (clay, silt), low nutrient load (especially phosphorus, which fuels algae), and low chlorophyll-a (active algae biomass). Deep lakes with rocky basins and forested watersheds tend to be clearest because they take in little soil runoff and few nutrients. Shallow lakes in farmed watersheds are typically less clear because they receive more sediment and fertilizer runoff.

Is the clearest lake the cleanest?

Not always. Clarity (Secchi depth) is measured and shown; nutrient and algae readings (total phosphorus and chlorophyll-a) are a separate measurement, compared against that lake’s EPA ecoregion classes. A lake can be very clear but still have elevated phosphorus that just hasn't bloomed yet. See our companion cleanest-lakes ranking for Virginia for the nutrient-and-algae list.

Where to stay near Virginia's clearest lakes

Planning a trip? Jump to live cabin, resort, and hotel availability near Virginia's clearest lakes.

Clearest lakes across all states →Cleanest lakes in Virginia (combined score) →All Virginia lakes →

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