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LakeQuality

Data Report · Updated July 2026

The State of Nebraska’s Lakes 2026

Of 106 monitored lakes in Nebraska, 14.2% earn a water-quality grade of A or B and 64.2% score D or F (average grade D). Nla Lake is the cleanest;

106
Monitored lakes graded
D
Average grade
14.2%
Grade A or B
0%
On impaired list

Nebraska grade distribution

B
C
D
F
A: 6 (5.7%)B: 9 (8.5%)C: 23 (21.7%)D: 33 (31.1%)F: 35 (33.0%)

Cleanest lakes in Nebraska

Highest combined water-quality score, 2026.

  1. 1.ANla Lake — Morrill County21 µg/L P · 1 µg/L chl-a
  2. 2.AQacnelakefbk — Douglas County11 µg/L P · 3 µg/L chl-a
  3. 3.BLake Minatare — Scotts Bluff County5.4 ft clarity · 52 µg/L P · 3 µg/L chl-a
  4. 4.BHershey Lake — Lincoln County13.6 ft clarity · 51 µg/L P · 2 µg/L chl-a
  5. 5.BNla Lake — Dawes County11.8 ft clarity · 35 µg/L P · 6 µg/L chl-a
  6. 6.BLake C W Mcconaughy — Keith County7.2 ft clarity · 57 µg/L P · 5 µg/L chl-a
  7. 7.BBox Butte Reservoir — Dawes County5.6 ft clarity · 52 µg/L P · 5 µg/L chl-a
  8. 8.CEnders Reservoir — Chase County2.8 ft clarity · 56 µg/L P · 10 µg/L chl-a
  9. 9.CCub Creek Lake — Keya Paha County4.9 ft clarity · 48 µg/L P · 8 µg/L chl-a
  10. 10.CNla Lake — Holt County2.7 ft clarity · 48052 µg/L P · 3 µg/L chl-a

Most-polluted lakes

Lowest combined water-quality score among monitored lakes.

  1. 1.FMaskenthine Reservoir — Stanton County2.1 ft clarity · 151 µg/L P · 63 µg/L chl-a
  2. 2.FNla Lake — Lincoln County0.5 ft clarity · 210688 µg/L P · 248 µg/L chl-a
  3. 3.FNla Lake — Lancaster County0.9 ft clarity · 159640 µg/L P · 249 µg/L chl-a
  4. 4.FNla Lake — Cherry County0.5 ft clarity · 709 µg/L P · 194 µg/L chl-a
  5. 5.FNla Lake — Garden County0.1 ft clarity · 3636000 µg/L P · 208 µg/L chl-a
  6. 6.FNla Lake — Rock County0.6 ft clarity · 268000 µg/L P · 114 µg/L chl-a
  7. 7.FNla Lake — Gage County0.5 ft clarity · 1399000 µg/L P · 224 µg/L chl-a
  8. 8.FNla Lake — Saunders County0.8 ft clarity · 225000 µg/L P · 160 µg/L chl-a
  9. 9.FNla Lake — Wheeler County1.3 ft clarity · 118648 µg/L P · 158 µg/L chl-a
  10. 10.FNla Lake — Cherry County0.5 ft clarity · 578254 µg/L P · 397 µg/L chl-a

Worst algae hotspots

Highest measured chlorophyll-a (algae) concentration.

  1. 1.FNla Lake — Cherry County397 µg/L chlorophyll-a
  2. 2.FNla Lake — Lancaster County249 µg/L chlorophyll-a
  3. 3.FNla Lake — Lincoln County248 µg/L chlorophyll-a
  4. 4.FNla Lake — Gage County224 µg/L chlorophyll-a
  5. 5.FNla Lake — Garden County208 µg/L chlorophyll-a
  6. 6.FNla Lake — Cherry County194 µg/L chlorophyll-a
  7. 7.FNla Lake — Garden County192 µg/L chlorophyll-a
  8. 8.FNla Lake — Saunders County160 µg/L chlorophyll-a
  9. 9.FNla Lake — Wheeler County158 µg/L chlorophyll-a
  10. 10.FNla Lake — Jefferson County126 µg/L chlorophyll-a

Explore Nebraska lakes

Lake Fishing Forecast

Species activity outlook by water temperature and season

Grades combine Secchi clarity, total phosphorus, and chlorophyll-a from the EPA Water Quality Portal and state agencies. See the full methodology, the national State of America’s Lakes report, or all Nebraska lakes.

Cite this report: LakeQuality, “The State of Nebraska’s Lakes 2026,” lakequality.org/report/ne.