Updated Aug 2026
Utah Lake Water Quality
Water quality grades for 96 of the 304 lakes we list here, across 29 counties.
Grade Distribution
All 304 Utah lakes in the index: 96 (31.6%) carry an A–F grade and 208 (68.4%) are not rated, because they lack enough recent nutrient or algae sampling to support a letter.
Top-Graded Utah Lakes
The highest water-quality grades in Utah — clarity, depth, and A-F grade at a glance.
Lake Map
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New grades, clarity readings, and algae advisories for Utah lakes as samples come in. Unsubscribe anytime.
Where to stay near Utah's top-graded lakes
Cabins, resorts, and vacation rentals around Flaming Gorge Reservoir (Daggett County, UT) and the other top-graded Utah lakes pinned on the map. Live availability and prices.
Top-rated places to stay near Flaming Gorge Reservoir (Daggett County, UT)
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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Explore Utah Lakes
Utah reports, fishing & travel
Reservoirs in Utah
View all 81 reservoirs →81 of 304 Utah lakes (27%) are man-made reservoirs in the USACE National Inventory of Dams. 78 carry a High or Significant hazard rating. The oldest matched dam dates to 1875.
EPA-Impaired Lakes in Utah
View all 55 impaired lakes →55 of 304 Utah lakes (18%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 28 have an approved Total Maximum Daily Load (TMDL) restoration plan.
Utah Fishing & Recreation
Licenses, regulations, records, and where to fish across Utah.
Counties
All 29 Utah 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.
Top 25 Cleanest Lakes
25 lakes25 graded lakes
| # | Lake | County | Grade | Clarity | Trophic | Access |
|---|---|---|---|---|---|---|
| 1 | AFlaming Gorge Reservoir Antelope Flat | Daggett | A | 25.3 ft | Oligotrophic | Not recorded |
| 2 | AFlaming Gorge Reservoir | Daggett | A | 31.8 ft | Oligotrophic | Not recorded |
| 3 | AWide Hollow Reservoir | Garfield | A | 13.8 ft | Mesotrophic | ✓ Public |
| 4 | AStarvation Reservoir | Duchesne | A | 11.2 ft | Oligotrophic | ✓ Public |
| 5 | ARecapture Reservoir | San Juan | A | 8.9 ft | Oligotrophic | Not recorded |
| 6 | ALittle Dell Reservoir | Salt Lake | A | 14.8 ft | Oligotrophic | Not recorded |
| 7 | ARed Fleet Reservoir | Uintah | A | 5.9 ft | Oligotrophic | ✓ Public |
| 8 | ASilver Lake Flat Reservoir | Utah | A | 10.5 ft | Oligotrophic | Not recorded |
| 9 | ASalem Pond | Utah | A | 5.9 ft | Mesotrophic | Not recorded |
| 10 | ASettlement Canyon Reservoir | Tooele | A | 8.5 ft | Oligotrophic | Not recorded |
| 11 | AGrantsville Reservoir | Tooele | A | 5.9 ft | Mesotrophic | Not recorded |
| 12 | ALake Mary | Salt Lake | A | 26.9 ft | Oligotrophic | Not recorded |
| 13 | AMillsite Reservoir | Emery | A | 10.5 ft | Oligotrophic | ✓ Public |
| 14 | AGunlock Reservoir | Washington | A | 4.6 ft | Mesotrophic | ✓ Public |
| 15 | ANewton Reservoir | Cache | A | 15.4 ft | Oligotrophic | Not recorded |
| 16 | ADmad Reservoir N of Cut | Millard | A | 0.7 ft | Mesotrophic | Not recorded |
| 17 | AGunnison Bend Reservoir | Millard | A | 1.5 ft | Mesotrophic | Not recorded |
| 18 | AHyrum Reservoir | Cache | A | 6.9 ft | Mesotrophic | ✓ Public |
| 19 | AMantua Reservoir N | Box Elder | A | 3 ft | Oligotrophic | Not recorded |
| 20 | ABig Sand Wash Reservoir | Duchesne | A | 10.7 ft | Mesotrophic | Not recorded |
| 21 | ABrough Reservoir | Uintah | A | 6.2 ft | Mesotrophic | Not recorded |
| 22 | AMoon Lake | Duchesne | A | 9.5 ft | Mesotrophic | Not recorded |
| 23 | ARed Creek Reservoir | Duchesne | A | 14.4 ft | Mesotrophic | Not recorded |
| 24 | AThird Dam Lake | Cache | A | 4.3 ft | Oligotrophic | Not recorded |
| 25 | AQuail Creek Reservoir | Washington | A | 14.6 ft | Oligotrophic | Not recorded |
25 Lakes Needing Attention
25 lakes25 graded lakes
| # | Lake | County | Grade | Clarity |
|---|---|---|---|---|
| 1 | FFarmington Bay Lake | Davis | F | No recent samples |
| 2 | FUtah Lake Sp @ Marina | Utah | F | 0.7 ft |
| 3 | FYuba Reservoir Midway | Juab | F | 2.8 ft |
| 4 | FKoosharem Reservoir | Sevier | F | 7.2 ft |
| 5 | DGsl Breach Lake | Box Elder | D | No recent samples |
| 6 | DWillard Pond East End | Box Elder | D | 6.4 ft |
| 7 | DWillard Pond West End | Box Elder | D | 4.3 ft |
| 8 | DBirch Creek Reservoir | Rich | D | 7.4 ft |
| 9 | DAnderson Meadow Reservoir | Beaver | D | 10.2 ft |
| 10 | DMatt Warner Reservoir E | Uintah | D | 6.2 ft |
| 11 | DPanguitch L Shore Lake | Garfield | D | 5.7 ft |
| 12 | DMiller Flat Reservoir | Emery | D | 10.2 ft |
| 13 | DBrowne Lake | Daggett | D | 6.6 ft |
| 14 | DHoop Lake | Summit | D | 5.6 ft |
| 15 | DBaker Dam Reservoir | Washington | D | 3.6 ft |
| 16 | DWoodruff Creek Reservoir | Rich | D | 11.5 ft |
| 17 | DWhitney Reservoir | Summit | D | 17.7 ft |
| 18 | DOtter Creek Reservoir | Piute | D | 5.2 ft |
| 19 | DRedmond Lake | Sevier | D | 0.7 ft |
| 20 | DPiute Reservoir | Piute | D | 1 ft |
| 21 | DStrawberry Reservoir Indian Creek Bay T | Wasatch | D | 16.4 ft |
| 22 | DScofield Reservoir | Carbon | D | 12.5 ft |
| 23 | DMill Meadow Reservoir | Wayne | D | 5.9 ft |
| 24 | DElectric Lake | Emery | D | 10.8 ft |
| 25 | DJohnson Reservoir | Sevier | D | 2 ft |
Utah lists 304 lakes across 29 counties, 96 of which carry a grade. Most of the input behind those grades flows through monitoring run by the Utah Division of Water Quality, which feeds state, federal, and volunteer measurements into the EPA Water Quality Portal. The remainder are here because they are real named lakes, not because anyone has sampled them recently. Roughly 32% of the state's graded lakes carry an A, 31 lakes that earn the top bracket on the combined Secchi, phosphorus and chlorophyll-a rubric. That share is high by national standards and reflects the depth and natural clarity of glacial lakes in the region.
Sevier Lake is the largest lake in this index at about 122,528 acres, one of 24 here that clear 500 acres. The rest run smaller, and small and shallow is where nutrient loading shows up first, because there is less water to dilute it and the bottom sediment stays within reach of the sun. Most graded Utah lakes sit in the mesotrophic band: moderate productivity, decent clarity, capable of supporting both warm-water and cool-water fisheries. This is the band where well-managed working lakes tend to land. Millard ranks highest on average county grade (A), and Davis sits lowest. With only 29 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.