Clark County Lake Quality
Nevada, 7 lakes, average grade C (Fair)
Clark County has 7 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.
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. Nla Lake (B) is the cleanest in the county.
Quick Answers for Clark County
Planning a trip? Check special fishing regulations for Nla Lake — or check the official Nevada fishing regulations.
All Lakes in Clark County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Nla Lake | B | 0.9 ft | 44.1 µg/L |
| 2 | Nla Lake | B | 4.8 ft | 20.4 µg/L |
| 3 | Berris Tinaja Lake | B | - | 24 µg/L |
| 4 | Ionactis Tinaja Lake | C | - | 31 µg/L |
| 5 | Indian Gardens Tinaja Lake | D | - | 69 µg/L |
| 6 | Mckay Wash Tinaja Lake | D | - | 89.5 µg/L |
| 7 | Hidden Valley Tinaja Lake | F | - | 288.5 µg/L |
Other Counties in Nevada
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
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Source: EPA National Aquatic Resource Surveys, 2026.