Impaired Lakes in Kentucky
69 of 108 graded Kentucky lakes (64%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 1 have an approved TMDL restoration plan.
Top Causes of Impairment in Kentucky
Reading the Kentucky impairment landscape
64% of Kentucky's tracked lakes — 69 of 108 — appear on the EPA Clean Water Act §303(d) impaired-waters list. At that share, impairment is the default state rather than an exception: the majority of lakes are flagged for at least one pollutant exceeding water-quality standards. Trip-planning for clean water in Kentucky typically requires checking impairment status as a first filter, not as an edge case.
The leading impairment category in Kentucky is Nutrients (phosphorus, nitrogen) — nutrient enrichment, typically from agricultural fertilizer runoff, septic discharge, or stormwater carrying lawn-care residue. Nutrient-impaired lakes can still be safe for contact recreation in many conditions, but they're prone to algal blooms (including potentially toxic cyanobacteria) during warm-water periods. Check the state's beach-monitoring or harmful-algal-bloom dashboard before swimming on nutrient-impaired waters in summer.
Impaired-waters listings come from the state environmental agency's §303(d) submission to EPA, refreshed on a roughly 2-year cycle. A listed lake stays on the list until either a TMDL is established and the cleanup completes, or subsequent monitoring shows the pollutant concentrations no longer exceed water-quality standards. The list below reflects the most recent available Kentucky submission to the EPA Assessment, Total Maximum Daily Load Tracking and Implementation System (ATTAINS) dataset.
All 69 EPA-Listed Impaired Lakes in Kentucky
| Lake | County | Grade | Causes | TMDL |
|---|---|---|---|---|
| Grayson Lake | Carter | B | Mercury | — |
| Fishtrap Lake | Pike | B | PCBs | — |
| Freeman Lake | Hardin | B | Nutrients (phosphorus, nitrogen) | — |
| Cedar Creek Lake | Lincoln | B | Mercury | — |
| Turner Lake | Ballard | B | Nutrients (phosphorus, nitrogen) | — |
| Lake Malone | Logan | B | Mercury, Nutrients (phosphorus, nitrogen) | — |
| Moffit Lake | Union | B | Nutrients (phosphorus, nitrogen) | — |
| Lake Peewee | Hopkins | B | Nutrients (phosphorus, nitrogen) | — |
| Loch Mary Reservoir | Hopkins | B | Nutrients (phosphorus, nitrogen) | — |
| Lake Washburn | Ohio | B | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Shanty Hollow Lake | Warren | B | Nutrients (phosphorus, nitrogen) | — |
| Cap Mauzy Lake | Union | B | Nutrients (phosphorus, nitrogen) | — |
| Paintsville Lake | Johnson | C | Mercury | — |
| Dewey Lake | Floyd | C | Nutrients (phosphorus, nitrogen) | — |
| Smoky Valley Lake | Carter | C | Oxygen depletion (low DO) | — |
| Corinth Lake | Grant | C | Mercury, Nutrients (phosphorus, nitrogen) | — |
| Panbowl Lake | Breathitt | C | Nutrients (phosphorus, nitrogen) | — |
| Greenbrier Creek Reservoir | Montgomery | C | Nutrients (phosphorus, nitrogen) | — |
| Kincaid Lake | Pendleton | C | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Doe Run Lake | Kenton | C | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Carpenters Lake | Daviess | C | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Corbin City Reservoir | Laurel | C | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Lake Blythe | Christian | C | Nutrients (phosphorus, nitrogen) | — |
| Briggs Lake | Logan | C | Nutrients (phosphorus, nitrogen) | — |
| West Fork Drakes Reservoir | Simpson | C | Nutrients (phosphorus, nitrogen) | — |
| Caneyville Reservoir | Grayson | C | Nutrients (phosphorus, nitrogen) | — |
| Campbellsville City Reservoir | Taylor | D | Nutrients (phosphorus, nitrogen) | — |
| Guist Creek Lake | Shelby | D | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Taylor Fork Lake | Madison | D | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Boltz Lake | Grant | D | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Bullock Pen Lake | Boone | D | Mercury, Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| General Butler State Park Lake | Carroll | D | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Lake Elmer Davis | Owen | D | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Lake Reba | Madison | D | Mercury, Nutrients (phosphorus, nitrogen) | — |
| Herrington Lake | Garrard | D | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO), PCBs | — |
| Lake Jericho | Henry | D | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Mill Creek Lake | Monroe | D | Nutrients (phosphorus, nitrogen) | — |
| Shelby Lake | Shelby | D | Nutrients (phosphorus, nitrogen) | — |
| Lake Morris | Christian | D | Nutrients (phosphorus, nitrogen) | — |
| Fish Lake | Carlisle | D | Nuisance exotic species, Nutrients (phosphorus, nitrogen) | — |
| Energy Lake | Trigg | D | Nutrients (phosphorus, nitrogen) | — |
| Swan Pond | Ballard | D | Nutrients (phosphorus, nitrogen) | — |
| Metropolis Lake | McCracken | D | Nuisance exotic species, Nutrients (phosphorus, nitrogen) | — |
| Spa Lake | Logan | D | Nutrients (phosphorus, nitrogen) | — |
| Kingfisher Lakes | Daviess | D | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Honker Lake | Lyon | D | Noxious aquatic plants, Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | — |
| Winchester Reservoir | Clark | D | Nutrients (phosphorus, nitrogen) | — |
| Benjy Kinman Lake | Henry | D | Nutrients (phosphorus, nitrogen) | — |
| Herrington Lake | Boyle | NR | Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO), PCBs | — |
| Lake Linville | Rockcastle | NR | Nutrients (phosphorus, nitrogen) | — |
| Carr Fork Lake | Knott | NR | Mercury | — |
| Buckhorn Lake | Perry | NR | Mercury | — |
| Beaver Lake | Anderson | NR | Mercury, Noxious aquatic plants, Nutrients (phosphorus, nitrogen) +1 more | — |
| Willisburg Lake | Washington | NR | Nutrients (phosphorus, nitrogen) | — |
| Cave Run Lake | Morgan | NR | Mercury | — |
| Marion County Sportsmans Lake | Marion | NR | Nutrients (phosphorus, nitrogen) | — |
| Shelby Lake | Ballard | NR | Nutrients (phosphorus, nitrogen) | — |
| Taylorsville Lake | Spencer | NR | Mercury, Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO) | ✓ |
| Mc Neely Lake | Jefferson | NR | Mercury, Nutrients (phosphorus, nitrogen) | — |
| Mitchell Lake | Ballard | NR | Nutrients (phosphorus, nitrogen) | — |
| Flat Lake | Ballard | NR | Mercury | — |
| Fish Lake | Ballard | NR | Mercury | — |
| Buck Lake | Ballard | NR | Mercury | — |
| Long Pond | Ballard | NR | Nutrients (phosphorus, nitrogen) | — |
| Salem Lake | Larue | NR | Nutrients (phosphorus, nitrogen) | — |
| County Lake | Metcalfe | NR | Nutrients (phosphorus, nitrogen) | — |
| Barren River Lake | Barren | NR | Nutrients (phosphorus, nitrogen) | — |
| Lake George | Crittenden | NR | Nutrients (phosphorus, nitrogen) | — |
| Sportsman Club Lake | Taylor | NR | Nutrients (phosphorus, nitrogen) | — |
Frequently Asked Questions
How many lakes are impaired in Kentucky?
69 of 108 graded Kentucky lakes (64%) are listed as impaired in the most recent EPA ATTAINS reporting cycle. Of those, 69 are on the federal Clean Water Act §303(d) list and 1 have an approved Total Maximum Daily Load (TMDL) restoration plan.
What does Clean Water Act §303(d) mean?
Section 303(d) of the federal Clean Water Act requires every state to identify waters that don't meet water quality standards even after pollution control measures. Each listed water must then have a Total Maximum Daily Load (TMDL) developed — a plan that caps how much of each pollutant can enter the waterbody. The "303(d) list" is the impaired-waters list. The EPA reviews each state's list every two years.
What are the top causes of impairment in Kentucky?
The most common causes flagged across Kentucky's impaired lakes are: Nutrients (phosphorus, nitrogen) (58 lakes); Oxygen depletion (low DO) (19 lakes); Mercury (16 lakes); PCBs (3 lakes); Noxious aquatic plants (2 lakes); Nuisance exotic species (2 lakes). Mercury is widespread in fish tissue across the upper Midwest from atmospheric deposition. Nutrient impairment (phosphorus, nitrogen) typically reflects agricultural runoff and urban stormwater.
Can I swim in an impaired lake?
It depends on the cause of impairment. A lake impaired for "mercury in fish tissue" is generally safe to swim in — the warning is about long-term consumption of fish. A lake impaired for "pathogens" (E. coli) or "algal growth" may pose a swimming risk and often has a separate beach advisory. Check the cause categories listed for each lake below, and consult your state health department's beach monitoring program for current advisories.
Where does this impairment data come from?
Every impairment record on this page comes from the EPA's ATTAINS (Assessment and TMDL Tracking and Implementation System) public dataset, the federal repository of state-reported water quality assessments. EPA ATTAINS is published as GeoParquet files on the EPA Office of Water S3 bucket and refreshed several times per year. Causes and use-support codes follow EPA's standard taxonomy.
More on impaired waters
What it means when a lake is listed as impaired, why mercury is the most common reason, and why a listed lake can still be clear water with a good grade.
Why states issue fish-consumption advisories, which contaminants — mercury, PCBs, PFAS — drive them, and how to eat the fish you catch more safely.
How phosphorus and nutrient runoff drive algae growth and turn lakes green, where the nutrients come from, and what it means for a lake's grade.
Which lakes are actually improving: multi-year EPA monitoring trends, the named recoveries still in progress, and what it takes to move a letter grade.
Data source
Impairment data from the EPA ATTAINS (Assessment and TMDL Tracking and Implementation System) public dataset. Assessment unit IDs are matched to LakeQuality lakes by name and proximity; some lakes may not appear here if their ATTAINS name doesn't match our naming convention. For an official query, consult .