Cleanest Lake in Virginia: Mouth of Witcher Cr. Lake (2026)

The single cleanest lake in Virginia is Mouth of Witcher Cr. Lake, ranked first on its measured clarity and nutrients in the 2026 sampling record. Cleanliness here is measured by Secchi depth (clarity), total phosphorus, and chlorophyll-a — all sourced from EPA Water Quality Portal and state agency sampling, shown as reported. The full top 25 ranked list appears below.

Ranking the cleanest Virginia lakes means picking the basins with the lowest nutrient and algae readings, then the clearer water among lakes that tie. Mouth of Witcher Cr. Lake leads the list, with Lower Blackwater River Lake close behind.

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

Rank	Lake	County	Clarity	Phosphorus	Chlorophyll-a	Area
1	Mouth of Witcher Cr. Lake	Bedford	11.2 ft	10 µg/L	1.9 µg/L	-
2	Lower Blackwater River Lake	Franklin	12.1 ft	10 µg/L	2.3 µg/L	-
3	Dam Lake	Franklin	12.1 ft	10 µg/L	1.7 µg/L	2,880 acres
4	Dam Lake	Pittsylvania	10.5 ft	10 µg/L	2 µg/L	20,400 acres
5	Dam Lake	Alleghany	12.1 ft	10 µg/L	1.7 µg/L	2,530 acres
6	Union Bridge Lake	Patrick	8.2 ft	10 µg/L	2.7 µg/L	-
7	Hidden Valley Lake	Washington	9.7 ft	10 µg/L	3.1 µg/L	60 acres
8	Hunting Run Reservior Lake	Spotsylvania	8.2 ft	10 µg/L	2.2 µg/L	443 acres
9	Goose Point Lake	Franklin	10.2 ft	10 µg/L	1.5 µg/L	-
10	Mouth Craddock Cr. Lake	Bedford	10.2 ft	10 µg/L	1.6 µg/L	-
11	Cool Branch Lake	Franklin	10.5 ft	10 µg/L	2.1 µg/L	-
12	Laurel Bed Lake	Russell	9.8 ft	10 µg/L	3.8 µg/L	395 acres
13	Confl. Blackwater River Lake	Bedford	9.8 ft	10 µg/L	2 µg/L	-
14	Mouth of Bull Run Lake	Franklin	10.2 ft	10 µg/L	2.1 µg/L	-
15	Carvins Cove Reservoir	Botetourt	11.5 ft	10 µg/L	1.2 µg/L	569 acres
16	Lee Hall Reservoir	Newport News city	4.8 ft	30 µg/L	5.8 µg/L	390 acres
17	Mouth Big Lick Cr. Lake	Alleghany	12.5 ft	10 µg/L	1.7 µg/L	-
18	Motts Run Reservoir	Spotsylvania	10.2 ft	10 µg/L	2.3 µg/L	160 acres
19	Wise Lake	Wise	10.5 ft	10 µg/L	2.2 µg/L	58 acres
20	Lake Robertson	Rockbridge	13.9 ft	10 µg/L	1.9 µg/L	26 acres
21	West Arm Lake	Pulaski	9.2 ft	10 µg/L	2.4 µg/L	-
22	Smith Lake	Stafford	8.2 ft	10 µg/L	2.3 µg/L	225 acres
23	Lake Keokee	Lee	9.7 ft	10 µg/L	2.6 µg/L	109 acres
24	Leesville Lakea-Topb-Middlec-Bot	Pittsylvania	5.2 ft	10 µg/L	4 µg/L	3,270 acres
25	North Fork Pound Reservoir	Wise	12.1 ft	10 µg/L	2 µg/L	154 acres

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

All-states list →Clearest lakes in Virginia (by Secchi clarity) →Minnesota version →Wisconsin version →Illinois version →Best swimming lakes in Virginia →All Virginia lakes →

Clearest lakes in Virginia 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 Virginia is Coles Run Reservoir at 25.8 ft of Secchi visibility.

1. Coles Run Reservoir — 25.8 ft, Augusta County
2. Lake Robertson — 13.9 ft, Rockbridge County
3. Above Dam Lake — 13.1 ft, Albemarle County
4. John Flannagan Reservoir — 13.1 ft, Dickenson County
5. Mouth Big Lick Cr. Lake — 12.5 ft, Alleghany County

See the full clearest-lakes ranking for Virginia →

Frequently Asked Questions

What is the cleanest lake in Virginia?

Mouth of Witcher Cr. Lake ranks first on measured clarity and nutrients in the 2026 Virginia sampling record. Each lake's nutrient and algae readings — total phosphorus, total nitrogen, chlorophyll-a, and turbidity — are shown beside the EPA National Lakes Assessment 2022 condition class for that lake's own ecoregion, so a reading is compared against the lakes it would naturally resemble. LakeQuality publishes no letter grade. Cleanliness here means a low nutrient load and little algae, measured directly from EPA and state DNR samples; where two lakes tie on nutrients and algae, the deeper Secchi reading ranks first.

Where in Virginia has the cleanest water?

Virginia'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 Franklin, Bedford, and Pittsylvania produce the highest-scoring lakes.

What is the clearest lake in Virginia?

Coles Run Reservoir is the clearest lake in Virginia by water clarity, with a Secchi depth of 25.8 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 Virginia for the top 25 by Secchi clarity.

Are these lakes safe to swim in?

Not on these readings alone. Clarity and nutrient readings are not a swimming clearance: they do 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 is this ranking calculated?

Lakes are ranked on phosphorus, chlorophyll-a and clarity as measured by EPA and state agency sampling, read against EPA National Lakes Assessment 2022 condition classes for that lake’s ecoregion, not a Virginia-only 0–100 average. Water clarity is shown beside the nutrient readings. Lakes with limited sampling do not headline the table.

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 Virginia, the 25 lakes ranked above have the lowest nutrient and algae readings 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 Virginia state norms and combined into a single 0–100 score. The lakes above are sorted by that combined score.Full methodology →

More on clean water

Lake Water Quality Explained: What the Readings Mean

How nutrient and algae readings are read against EPA ecoregion condition classes, what each class means in the water, and why a clean reading is not a clearance.

Cleanest Small Lakes in America 2026

The cleanest U.S. lakes under 500 acres, ranked on measured nutrients, algae, and water clarity — with the size cutoff applied to the lake, not the sample.

How to Choose a Clean Lake for a Cabin or Weekend Trip

A practical checklist for picking a lake with good water quality — clarity, phosphorus, algae history, depth, and the data to check before you commit.

Where to stay near Virginia's cleanest lakes

Compare cabins, resorts, and rentals around Mouth of Witcher Cr. Lake 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 Mouth of Witcher Cr. Lake

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Source: EPA National Aquatic Resource Surveys, 2026.