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Updated August 2026 · Top 25 of 110 lakes with a Secchi reading

Clearest Lake in Texas: Top 25 by Secchi Depth

Brandy Branch Reservoir in Harrison County is the clearest lake in Texas by Secchi depth, at 12 ft. Mapped and ranked below: the 25 clearest of 110 Texas lakes with a Secchi reading. Secchi depth is shown, not scored: the letter grades nutrients and algae, so a clear lake can be unrated or carry a lower grade than a murkier one.

Map · 25 ranked lakesTap a pin for its lake
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Graded A–FNot rated#1 in this rankingPins are this ranking's lakes at their surveyed locations.

How clear are Texas's clearest lakes?

From 12 ft at Brandy Branch Reservoir to 3.9 ft at #25, Lake Cisco; the median of the 25 is 4.8 ft.

#LakeCountySecchi depthGradeArea
1Brandy Branch ReservoirHarrison12 ftA1,242 acres
2Canyon LakeComal10.8 ftNR8,308 acres
3Waco LakeMcLennan9.8 ftNR7,270 acres
4Lake Alan HenryGarza9.4 ftA2,884 acres
5Lake Daingerfield HeadwatersMorris8.5 ftA69 acres
6Lake JacksonvilleCherokee7.4 ftA1,325 acres
7Lake HawkinsWood6.7 ftA1,064 acres
8Lake AthensHenderson5.9 ftC1,471 acres
9Lake GeorgetownWilliamson5.6 ftNR1,310 acres
10Lake MeredithHutchinson5.3 ftA16,513 acres
11Walter E Long Lake Western ArmTravis4.9 ftD
12Pinkston ReservoirShelby4.9 ftNR549 acres
13Whitney LakeHill4.8 ftD23,560 acres
14Lake Fork ReservoirWood4.6 ftNR27,690 acres
15Canyon Lake HeadwatersComal4.6 ftNR
16Lake Brownwood N End of DamBrown4.3 ftC7,300 acres
17Lost Creek Reservoir Mid LakeJack4.3 ftNR
18Walter E Long Lake Eastern ArmTravis4.2 ftD
19Ray Roberts Lake SiteDenton3.9 ftD
20Lake ColemanColeman3.9 ftC1,886 acres
21Possum Kingdom LakeStephens3.9 ftD
22Lake Bob SandlinCamp3.9 ftC
23Lake Palo PintoPalo Pinto3.9 ftD2,661 acres
24Sam Rayburn ReservoirSan Augustine3.9 ftC
25Lake CiscoEastland3.9 ftA

Sources and method

  • Secchi depth: Median of each lake's EPA Water Quality Portal readings, sampled January 2020 to May 2026, in feet. For 23 of these 25 lakes the submitting agency is Texas Commission on Environmental Quality. Portal: EPA Water Quality Portal.
  • Grade: A–F water-quality grade from nutrient and algae sampling (total phosphorus and chlorophyll-a) against the lake's EPA ecoregion classes, where enough recent samples exist to support one; the dashed NR mark otherwise. Clarity is not part of the grade, which is why a clear lake here can be unrated or carry a lower letter 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, colored by grade. No other lakes are plotted.

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Frequently Asked Questions

What is the clearest lake in Texas?

Brandy Branch Reservoir in Harrison County is the clearest lake in Texas by Secchi depth, at 12 ft. Secchi depth is measured by lowering a black-and-white disk until it disappears from view; a deeper reading means clearer water. Brandy Branch Reservoir holds an overall water-quality grade of A.

How clear are Texas's 25 clearest lakes?

They span 3.9 ft to 12 ft of Secchi depth, with a median of 4.8 ft. Brandy Branch Reservoir leads by 1.2 ft. Comal County has 2 of the 25; the rest are spread across 21 other counties. 18 of the 25 carry an A–F grade; the other 7 are not rated because their recent sampling does not support a letter.

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; the letter grades nutrients and algae (total phosphorus and chlorophyll-a) 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 Texas for the nutrient-and-algae list.

Where to stay near Texas's clearest lakes

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