The State of Utah's Lakes 2026

Cleanest lakes in Utah

Highest combined water-quality score, 2026.

1. 1.AFlaming Gorge Reservoir Antelope Flat — Daggett County25.3 ft clarity · 7 µg/L P · 1 µg/L chl-a
2. 2.AFlaming Gorge Reservoir — Daggett County31.8 ft clarity · 7 µg/L P · 1 µg/L chl-a
3. 3.AWide Hollow Reservoir — Garfield County13.8 ft clarity · 37 µg/L P · 3 µg/L chl-a
4. 4.AStarvation Reservoir — Duchesne County11.2 ft clarity · 10 µg/L P · 1 µg/L chl-a
5. 5.ARecapture Reservoir — San Juan County8.9 ft clarity · 15 µg/L P · 2 µg/L chl-a
6. 6.ARed Fleet Reservoir — Uintah County5.9 ft clarity · 20 µg/L P · 2 µg/L chl-a
7. 7.ANewton Reservoir — Cache County15.4 ft clarity · 26 µg/L P · 2 µg/L chl-a
8. 8.AHyrum Reservoir — Cache County6.9 ft clarity · 18 µg/L P · 2 µg/L chl-a
9. 9.AMoon Lake — Duchesne County9.5 ft clarity · 11 µg/L P · 3 µg/L chl-a
10. 10.BLake Powell Off Cha Canyon — San Juan County13.1 ft clarity · 9 µg/L P

Most-polluted lakes

Lowest combined water-quality score among monitored lakes.

1. 1.FUtah Lake Sp @ Marina — Utah County0.7 ft clarity · 132 µg/L P · 55 µg/L chl-a
2. 2.FFarmington Bay Lake — Davis County405 µg/L P · 106 µg/L chl-a
3. 3.DGsl Farmington Bay Outflow Lake — Davis County1.0 ft clarity · 485 µg/L P · 28 µg/L chl-a
4. 4.DLower Bowns Reservoir — Garfield County9.2 ft clarity · 34 µg/L P · 9 µg/L chl-a
5. 5.DCutler Reservoir — Cache County1.2 ft clarity · 109 µg/L P · 17 µg/L chl-a
6. 6.DMill Meadow Reservoir — Wayne County5.9 ft clarity · 66 µg/L P · 23 µg/L chl-a
7. 7.DBaker Dam Reservoir — Washington County3.6 ft clarity · 78 µg/L P · 30 µg/L chl-a
8. 8.DMatt Warner Reservoir E — Uintah County6.2 ft clarity · 72 µg/L P · 15 µg/L chl-a
9. 9.CJordanelle Reservoir — Wasatch County8.2 ft clarity · 20 µg/L P · 2 µg/L chl-a
10. 10.CMona Reservoir — Juab County2.0 ft clarity · 54 µg/L P · 4 µg/L chl-a

Worst algae hotspots

Highest measured chlorophyll-a (algae) concentration.

1. 1.FFarmington Bay Lake — Davis County106 µg/L chlorophyll-a
2. 2.CNewcastle Reservoir — Iron County89 µg/L chlorophyll-a
3. 3.FKoosharem Reservoir — Sevier County58 µg/L chlorophyll-a
4. 4.FUtah Lake Sp @ Marina — Utah County55 µg/L chlorophyll-a
5. 5.FYuba Reservoir Midway — Juab County38 µg/L chlorophyll-a
6. 6.DBaker Dam Reservoir — Washington County30 µg/L chlorophyll-a
7. 7.DJohnson Reservoir — Sevier County29 µg/L chlorophyll-a
8. 8.DGsl Farmington Bay Outflow Lake — Davis County28 µg/L chlorophyll-a
9. 9.DMill Meadow Reservoir — Wayne County23 µg/L chlorophyll-a
10. 10.DPanguitch L Shore Lake — Garfield County22 µg/L chlorophyll-a

Trending lakes

Improving

1. 1.ARecapture Reservoir — San Juan County
2. 2.ASalem Pond — Utah County
3. 3.AHyrum Reservoir — Cache County
4. 4.ABrough Reservoir — Uintah County
5. 5.AFerron Reservoir — Sanpete County
6. 6.APosey Lake — Garfield County
7. 7.APalisade Lake — Sanpete County
8. 8.ATropic Reservoir — Garfield County

Declining

1. 1.FKoosharem Reservoir — Sevier County
2. 2.DLower Bowns Reservoir — Garfield County
3. 3.DLake Powell Hite Midchannel — San Juan County
4. 4.DBig East Lake — Utah County
5. 5.DStrawberry Reservoir Indian Creek Bay T — Wasatch County
6. 6.DWhitney Reservoir — Summit County
7. 7.DWoodruff Creek Reservoir — Rich County
8. 8.DBaker Dam Reservoir — Washington County