Updated Aug 2026
Nevada Lake Water Quality
Water quality grades for 16 of the 223 lakes we list here, across 16 counties.
Grade Distribution
All 223 Nevada lakes in the index: 16 (7.2%) carry an A–F grade and 207 (92.8%) are not rated, because they lack enough recent nutrient or algae sampling to support a letter.
Top-Graded Nevada Lakes
The highest water-quality grades in Nevada — clarity, depth, and A-F grade at a glance.
Lake Map
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New grades, clarity readings, and algae advisories for Nevada lakes as samples come in. Unsubscribe anytime.
Where to stay near Nevada's top-graded lakes
Cabins, resorts, and vacation rentals around Comins Reservoir and the other top-graded Nevada lakes pinned on the map. Live availability and prices.
Top-rated places to stay near Comins Reservoir
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Explore Nevada Lakes
Nevada reports, fishing & travel
Reservoirs in Nevada
View all 20 reservoirs →20 of 223 Nevada lakes (9%) are man-made reservoirs in the USACE National Inventory of Dams. 13 carry a High or Significant hazard rating. The oldest matched dam dates to 1910.
EPA-Impaired Lakes in Nevada
View all 22 impaired lakes →22 of 223 Nevada lakes (10%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 1 have an approved Total Maximum Daily Load (TMDL) restoration plan.
Nevada Fishing & Recreation
Licenses, regulations, records, and where to fish across Nevada.
Counties
All 16 Nevada 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.
Cleanest Nevada Lakes
16 lakes16 graded lakes
| # | Lake | County | Grade | Clarity | Trophic | Access |
|---|---|---|---|---|---|---|
| 1 | AComins Reservoir | White Pine | A | No recent samples | Oligotrophic | Not recorded |
| 2 | ALake Tahoe | Douglas | A | No recent samples | Oligotrophic | ✓ Public |
| 3 | BIllipah Reservoir | White Pine | B | No recent samples | Mesotrophic | ✓ Public |
| 4 | CRye Patch Reservoir | Pershing | C | No recent samples | Mesotrophic | ✓ Public |
| 5 | CBoulder Reservoir | Washoe | C | No recent samples | Eutrophic | Not recorded |
| 6 | COnion Valley Reservoir @ Dam | Humboldt | C | No recent samples | Eutrophic | Not recorded |
| 7 | CSquaw Creek Reservoir | Washoe | C | No recent samples | Eutrophic | Not recorded |
| 8 | CSpooner Lake | Douglas | C | No recent samples | Eutrophic | Not recorded |
| 9 | DWalker Lake | Mineral | D | 4.7 ft | Eutrophic | Not recorded |
| 10 | DSheep Creek Lake | Elko | D | 6.2 ft | Eutrophic | Not recorded |
| 11 | DBilly Shaw Lake | Elko | D | No recent samples | Eutrophic | Not recorded |
| 12 | DMountain View Lake | Elko | D | No recent samples | Eutrophic | Not recorded |
| 13 | DBilk Creek Reservoir | Humboldt | D | No recent samples | Eutrophic | Not recorded |
| 14 | DWall Canyon Reservoir | Washoe | D | No recent samples | Hypereutrophic | Not recorded |
| 15 | FWildhorse Reservoir | Elko | F | 5.9 ft | Hypereutrophic | Not recorded |
| 16 | FKnott Creek Reservoir | Humboldt | F | No recent samples | Hypereutrophic | Not recorded |
Nevada Lakes Needing Attention
16 lakes16 graded lakes
| # | Lake | County | Grade | Clarity |
|---|---|---|---|---|
| 1 | FKnott Creek Reservoir | Humboldt | F | No recent samples |
| 2 | FWildhorse Reservoir | Elko | F | 5.9 ft |
| 3 | DWall Canyon Reservoir | Washoe | D | No recent samples |
| 4 | DBilk Creek Reservoir | Humboldt | D | No recent samples |
| 5 | DMountain View Lake | Elko | D | No recent samples |
| 6 | DBilly Shaw Lake | Elko | D | No recent samples |
| 7 | DSheep Creek Lake | Elko | D | 6.2 ft |
| 8 | DWalker Lake | Mineral | D | 4.7 ft |
| 9 | CSpooner Lake | Douglas | C | No recent samples |
| 10 | CSquaw Creek Reservoir | Washoe | C | No recent samples |
| 11 | COnion Valley Reservoir @ Dam | Humboldt | C | No recent samples |
| 12 | CBoulder Reservoir | Washoe | C | No recent samples |
| 13 | CRye Patch Reservoir | Pershing | C | No recent samples |
| 14 | BIllipah Reservoir | White Pine | B | No recent samples |
| 15 | ALake Tahoe | Douglas | A | No recent samples |
| 16 | AComins Reservoir | White Pine | A | No recent samples |
16 of the 223 Nevada lakes in this index carry an A–F water-quality grade, spread over 16 counties. Those grades rest on measurements from the Nevada Division of Environmental Protection, alongside federal programs and volunteer monitoring networks. The rest are listed for their size, depth and location, without enough recent nutrient or algae sampling behind them to support a letter.
By surface area the largest lake here is Lake Mead, at about 133,758 acres, and 53 of the lakes in this index cover more than 500 acres. Size is worth knowing before you go: a large deep basin buffers nutrient inputs by sheer volume, while a shallow one warms quickly and can turn over its whole water column in a single summer storm. White Pine ranks highest on average county grade (A), and Elko sits lowest. With only 16 counties in the state, the cross-county spread is narrower than the within-county spread for most lakes.
Lake Match
Which lake suits how you actually use one?
Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of graded lakes that fit, with the water quality behind each one.
Source: EPA National Aquatic Resource Surveys and the EPA Water Quality Portal.
More on lake water quality
A data snapshot of the lakes we grade: how the A–F distribution breaks down, the clearest and the greenest states, and where the water is improving.
How lakes are graded A–F on nutrients and algae using EPA ecoregion condition classes, what each letter means in the water, and why an A is not a clearance.
The cleanest and dirtiest U.S. lakes in the monitoring record, ranked on EPA nutrient and algae condition classes across thousands of graded lakes.
The clearest lakes in America, ranked by measured Secchi depth in feet from EPA monitoring data — and why the famously clear lakes are missing.