Updated Jul 2026
Oklahoma Lake Water Quality
Water quality grades for 34 monitored lakes across 17 counties.
{{stateName}} has 34 graded lakes in our dataset, sampled across 17 counties, drawing on monitoring by {{agency}} plus federal and volunteer measurements. Only about 3% of {{stateName}}'s lakes pull an A grade — the smaller, agricultural-watershed lakes that dominate the dataset tend to carry persistent nutrient loads. 56% of lakes fall in the D or F brackets.
The state's lakes lean eutrophic: enough nutrient input to support an active algal community, with the trade-offs in clarity and dissolved oxygen that come with it. Grayson ranks highest on average county grade (C). Johnston sits lowest. With only 17 counties in the state, the cross-county spread is narrower than the within-county spread for most lakes.
Grade Distribution
How Oklahoma’s 34 graded lakes break down from A (excellent) to F.
Top-Graded Oklahoma Lakes
The highest water-quality grades in Oklahoma — clarity, depth, and A-F grade at a glance.
Lake Thunderbird Norman
Cleveland County, Oklahoma
See grade for Lake Thunderbird Norman →Lake Texoma
Grayson County, Oklahoma
See grade for Lake Texoma →Greenleaf Lake
Muskogee County, Oklahoma
See grade for Greenleaf Lake →Lake Konawa
Seminole County, Oklahoma
See grade for Lake Konawa →Wes Watkins Reservoir
Pottawatomie County, Oklahoma
See grade for Wes Watkins Reservoir →Spavinaw Lake
Mayes County, Oklahoma
See grade for Spavinaw Lake →Lake Chickasha
Caddo County, Oklahoma
See grade for Lake Chickasha →Eucha Lake
Delaware County, Oklahoma
See grade for Eucha Lake →Sportsman Lake
Seminole County, Oklahoma
See grade for Sportsman Lake →Lake Map
Explore Oklahoma Lakes
Oklahoma reports, fishing & travel
Oklahoma Fishing & Recreation
Licenses, regulations, records, and where to fish across Oklahoma.
Counties
All 17 Oklahoma counties, ranked by average lake water quality. Compare them against every county nationwide in the county rankings, browse the full directory of graded lakes, or pick a different state.
Top 25 Cleanest Lakes
| Rank | Lake | County | Grade | Clarity |
|---|---|---|---|---|
| 1 | Lake Thunderbird Norman | Cleveland | A | - |
| 2 | Lake Texoma | Grayson | C | 4.2 ft |
| 3 | Greenleaf Lake | Muskogee | C | 2.5 ft |
| 4 | Lake Konawa | Seminole | C | 3.1 ft |
| 5 | Wes Watkins Reservoir | Pottawatomie | C | 1.8 ft |
| 6 | Spavinaw Lake | Mayes | C | 3.3 ft |
| 7 | Lake Chickasha | Caddo | C | 1.5 ft |
| 8 | Eucha Lake | Delaware | C | 3.1 ft |
| 9 | Sportsman Lake | Seminole | C | 6.2 ft |
| 10 | Wewoka Lake | Seminole | C | 2.5 ft |
| 11 | Thunderbird Lake Hog Creek | Cleveland | C | - |
| 12 | Lake Texoma | Bryan | C | 3.2 ft |
| 13 | Lake Thunderbird | Cleveland | C | 1.7 ft |
| 14 | Thunderbird Lake Nature Center | Pottawatomie | C | - |
| 15 | Thunderbird Lake Fisherman'S | Cleveland | C | - |
| 16 | Copan Lake | Washington | D | 1.6 ft |
| 17 | Washunga Bay Lake | Kay | D | - |
| 18 | Sandy Beach Lake | Osage | D | - |
| 19 | Ponca Lake A | Kay | D | - |
| 20 | Sarge Creek Lake | Kay | D | - |
| 21 | Osage Cove Lake | Osage | D | - |
| 22 | Pioneer Cover Lake | Osage | D | - |
| 23 | Thunderbird Lake Indianhills | Cleveland | D | - |
| 24 | Lake Texoma | Marshall | D | 1.7 ft |
| 25 | Coon Creek Lake | Kay | D | - |
25 Lakes Needing Attention
| Rank | Lake | County | Grade | Clarity |
|---|---|---|---|---|
| 1 | Ft. Cobb Lake | Caddo | F | - |
| 2 | Lake Hugo Hugo | Choctaw | F | - |
| 3 | Lake Sardis Clayton | Pushmataha | F | - |
| 4 | Lake Nahni Waiya Tuskahomma | Pushmataha | F | - |
| 5 | Veteran'S Lake | Lincoln | F | - |
| 6 | Bear Creek Lake | Kay | F | - |
| 7 | Ponca Lake B | Kay | F | - |
| 8 | Grand Lake | Delaware | F | 1.6 ft |
| 9 | Lake Texoma | Johnston | F | 0.3 ft |
| 10 | Coon Creek Lake | Kay | D | - |
| 11 | Lake Texoma | Marshall | D | 1.7 ft |
| 12 | Thunderbird Lake Indianhills | Cleveland | D | - |
| 13 | Pioneer Cover Lake | Osage | D | - |
| 14 | Osage Cove Lake | Osage | D | - |
| 15 | Sarge Creek Lake | Kay | D | - |
| 16 | Ponca Lake A | Kay | D | - |
| 17 | Sandy Beach Lake | Osage | D | - |
| 18 | Washunga Bay Lake | Kay | D | - |
| 19 | Copan Lake | Washington | D | 1.6 ft |
| 20 | Thunderbird Lake Fisherman'S | Cleveland | C | - |
| 21 | Thunderbird Lake Nature Center | Pottawatomie | C | - |
| 22 | Lake Thunderbird | Cleveland | C | 1.7 ft |
| 23 | Lake Texoma | Bryan | C | 3.2 ft |
| 24 | Thunderbird Lake Hog Creek | Cleveland | C | - |
| 25 | Wewoka Lake | Seminole | C | 2.5 ft |
Where to stay near Oklahoma
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Source: EPA National Aquatic Resource Surveys, 2026.