Updated Aug 2026
Nebraska Lake Water Quality
Water quality grades for 69 monitored lakes across 49 counties.
69 Nebraska lakes carry a grade. Most of the input data flows through monitoring run by the Nebraska Department of Environment and Energy, which feeds state, federal, and volunteer measurements into the EPA Water Quality Portal. A-grade lakes are scarce in Nebraska: about 12% of the dataset. Most lakes here sit in C or D — productive, often shallow, frequently algal in late summer.
A meaningful share of the state's monitored lakes register as hypereutrophic — heavily nutrient-loaded, frequent blooms, low summer transparency. These are usually shallow, surrounded by row-crop agriculture, with little volume to buffer the inputs. Sherman ranks highest on average county grade (A). Buffalo sits lowest. With only 49 counties in the state, the cross-county spread is narrower than the within-county spread for most lakes.
Grade Distribution
All 69 Nebraska lakes in the index: 52 (75.4%) carry an A–F grade and 17 (24.6%) are not rated, because they lack enough recent nutrient or algae sampling to support a letter.
Where to stay near Nebraska
Top-rated places to stay near Nebraska
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Top-Graded Nebraska Lakes
The highest water-quality grades in Nebraska — clarity, depth, and A-F grade at a glance.
Lake Map
Explore Nebraska Lakes
Nebraska reports, fishing & travel
Reservoirs in Nebraska
View all 52 reservoirs →52 of 69 Nebraska lakes (75%) are man-made reservoirs in the USACE National Inventory of Dams. 36 carry a High or Significant hazard rating. The oldest matched dam dates to 1895.
EPA-Impaired Lakes in Nebraska
View all 60 impaired lakes →60 of 69 Nebraska lakes (87%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 7 have an approved Total Maximum Daily Load (TMDL) restoration plan.
Nebraska Fishing & Recreation
Licenses, regulations, records, and where to fish across Nebraska.
Counties
All 49 Nebraska 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 | ALake C W Mcconaughy | Keith | A | 7.2 ft | Mesotrophic | ✓ Public |
| 2 | ASherman Reservoir | Sherman | A | 2.4 ft | Mesotrophic | ✓ Public |
| 3 | ADavis Creek Reservoir | Greeley | A | 3.9 ft | Mesotrophic | ✓ Public |
| 4 | ALake Carter P Johnson | Sioux | A | 8.3 ft | Mesotrophic | Not recorded |
| 5 | ALake Minatare | Scotts Bluff | A | 5.5 ft | Mesotrophic | ✓ Public |
| 6 | AHershey Lake | Lincoln | A | 13.6 ft | Mesotrophic | ✓ Public |
| 7 | ABridgeport Middle Lake | Morrill | A | 18.9 ft | Oligotrophic | ✓ Public |
| 8 | AHugh Butler Lake | Frontier | A | 2.8 ft | Mesotrophic | ✓ Public |
| 9 | BCalamus Reservoir | Garfield | B | 3.6 ft | Eutrophic | ✓ Public |
| 10 | BCub Creek Lake | Keya Paha | B | 4.9 ft | Eutrophic | Not recorded |
| 11 | BLake Maloney | Lincoln | B | 2.1 ft | Eutrophic | ✓ Public |
| 12 | BMerritt Reservoir | Cherry | B | 2 ft | Hypereutrophic | ✓ Public |
| 13 | BPelican Lake | Cherry | B | 1.2 ft | Hypereutrophic | ✓ Public |
| 14 | BOliver Reservoir | Kimball | B | 1.7 ft | Eutrophic | Not recorded |
| 15 | BSmith Lake | Sheridan | B | 1.7 ft | Hypereutrophic | ✓ Public |
| 16 | BChalkrock Lake | Cedar | B | 3.3 ft | Eutrophic | ✓ Public |
| 17 | BSkyview Lake | Madison | B | 6.2 ft | Eutrophic | ✓ Public |
| 18 | BLake Whitney | Dawes | B | 0.5 ft | Eutrophic | ✓ Public |
| 19 | BCrescent Lake | Garden | B | 0.8 ft | Hypereutrophic | ✓ Public |
| 20 | BGoose Lake | Holt | B | 1 ft | Hypereutrophic | ✓ Public |
| 21 | BSwanson Reservoir | Hitchcock | B | 2.6 ft | Eutrophic | ✓ Public |
| 22 | BSwan Lake | Holt | B | 1.8 ft | Hypereutrophic | Not recorded |
| 23 | CBox Butte Reservoir | Dawes | C | 5.6 ft | Mesotrophic | ✓ Public |
| 24 | CHarry Strunk Lake | Frontier | C | 2.5 ft | Eutrophic | ✓ Public |
| 25 | CPibel Lake | Wheeler | C | 2 ft | Hypereutrophic | ✓ Public |
25 Lakes Needing Attention
25 lakes25 graded lakes
| # | Lake | County | Grade | Clarity |
|---|---|---|---|---|
| 1 | FRavenna Lake E of Ravenna | Buffalo | F | No recent samples |
| 2 | FWildwood Lake | Lancaster | F | 1.7 ft |
| 3 | FBuckskin Hills Lake | Dixon | F | 2.4 ft |
| 4 | FBurchard Lake | Pawnee | F | 1.9 ft |
| 5 | FMeadowlark Lake | Seward | F | 1.8 ft |
| 6 | FHedgefield Lake | Lancaster | F | 1.6 ft |
| 7 | FGrove Lake | Antelope | F | 2.1 ft |
| 8 | FBig Indian Lake | Gage | F | 1.5 ft |
| 9 | FLiberty Cove Lake | Webster | F | 2.2 ft |
| 10 | FRockford Lake | Gage | F | 1.7 ft |
| 11 | FSummit Lake | Burt | F | 2.6 ft |
| 12 | FSwan Creek Lake | Saline | F | 1.5 ft |
| 13 | FWillow Creek Reservoir | Sarpy | F | 1.5 ft |
| 14 | FLone Star Reservoir | Fillmore | F | 2.1 ft |
| 15 | FMaskenthine Reservoir | Stanton | F | 2.1 ft |
| 16 | DOxbow Trails Reservoir | Butler | D | 1.3 ft |
| 17 | DLake Ogallala | Keith | D | 4.9 ft |
| 18 | DPrairie Queen Lake | Sarpy | D | 3.3 ft |
| 19 | DPowder Creek Lake | Dixon | D | 2.7 ft |
| 20 | DLake Wanahoo | Saunders | D | 2.4 ft |
| 21 | DJenny Newman Lake | Cass | D | 5.4 ft |
| 22 | DHarlan County Reservoir | Harlan | D | 2.8 ft |
| 23 | DCarter Lake Max Depth | Douglas | D | 1.3 ft |
| 24 | DJohnson Lake | Gosper | D | 2.8 ft |
| 25 | DEnders Reservoir | Chase | D | 2.8 ft |
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
The top-graded lake in every state we cover, picked grade-first with water clarity as the tie-breaker — plus the states whose winner is still not clean.
State-by-state Secchi champions: the clearest measured lake in each U.S. state we grade, which is not the same as the cleanest nutrient grade.
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.