Benton County Lake Quality
Arkansas, 14 lakes, average grade C (Fair)
Only 14 lakes in Benton County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. The county average is C — the middle of the rubric, with one or two lakes pulling the average up or down depending on year.
The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Lake Brittany (A); the most-stressed is Siloam Springs Lake (D).
Quick Answers for Benton County
Planning a trip? Check special fishing regulations for Lake Brittany — or check the official Arkansas fishing regulations.
All Lakes in Benton County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Lake Brittany | A | - | - |
| 2 | Lake Ann | B | - | 27 µg/L |
| 3 | Norwood Lake | B | - | 22.5 µg/L |
| 4 | Loch Lomond Lake | B | - | 22 µg/L |
| 5 | Lake Rayburn | B | - | 22 µg/L |
| 6 | Lake Windsor | B | - | 34 µg/L |
| 7 | Lake Avalon | B | - | 27 µg/L |
| 8 | Beaver Lake | C | 4.6 ft | 25 µg/L |
| 9 | Partners Lake_spillway | C | 7.5 ft | - |
| 10 | Lake Atalanta | D | 6.5 ft | - |
| 11 | Swepco Lake | D | - | 70.5 µg/L |
| 12 | Crystal Lake | D | - | 40 µg/L |
| 13 | Siloam Springs Lake | D | - | 70 µg/L |
Other Counties in Arkansas
See how Benton County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 34 states.
Where to stay near Benton County
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Source: EPA National Aquatic Resource Surveys, 2026.