Thomas County Lake Quality
Kansas, 1 lakes, average grade B (Good)
Thomas County has 1 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. With an average grade of B, Thomas County sits comfortably above the {{stateName}} median.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Colby City Pond (B) is the cleanest in the county.
Quick Answers for Thomas County
Planning a trip? Check special fishing regulations for Colby City Pond — or check the official Kansas fishing regulations.
All Lakes in Thomas County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Colby City Pond | B | - | 0.3 µg/L |
Other Counties in Kansas
See how Thomas 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 Thomas County
Top-rated places to stay near Thomas County
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Source: EPA National Aquatic Resource Surveys, 2026.