Clark County Lake Quality
Kansas, 3 lakes, average grade C (Fair)
Clark County has 3 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. Clark County averages to a C. The distribution behind that average matters more than the letter: a few stressed lakes versus many decent ones can produce the same average as the inverse.
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 St Jacobs Well Lake (B); the most-stressed is Nla Lake (D).
Quick Answers for Clark County
Planning a trip? Check special fishing regulations for St Jacobs Well Lake — or check the official Kansas fishing regulations.
All Lakes in Clark County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | St Jacobs Well Lake | B | 5.2 ft | 27.5 µg/L |
| 2 | Nla Lake | D | 3 ft | 53000 µg/L |
| 3 | Clark Co State Fishing Lake | D | 2.7 ft | 62 µg/L |
Other Counties in Kansas
See how Clark 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 Clark County
Top-rated places to stay near Clark County
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Source: EPA National Aquatic Resource Surveys, 2026.