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LakeQuality

Data Report · Updated July 2026

The State of Kansas’s Lakes 2026

Of 222 monitored lakes in Kansas, 19.8% earn a water-quality grade of A or B and 55% score D or F (average grade D). Wilson Lake is the cleanest;

222
Monitored lakes graded
D
Average grade
19.8%
Grade A or B
0%
On impaired list

Kansas grade distribution

B
C
D
F
A: 7 (3.2%)B: 37 (16.7%)C: 56 (25.2%)D: 76 (34.2%)F: 46 (20.7%)

Cleanest lakes in Kansas

Highest combined water-quality score, 2026.

  1. 1.AWilson Lake — Russell County8.7 ft clarity · 0 µg/L P · 3 µg/L chl-a
  2. 2.APottawatomie State Fishing Lake — Pottawatomie County8.3 ft clarity · 0 µg/L P · 2 µg/L chl-a
  3. 3.ANla Lake — Wyandotte County9.9 ft clarity · 14 µg/L P · 5 µg/L chl-a
  4. 4.APottawatomie State Fishing Lake — Pottawatomie County7.6 ft clarity · 15 µg/L P · 5 µg/L chl-a
  5. 5.BCedar Bluff Lake — Trego County5.9 ft clarity · 0 µg/L P · 12 µg/L chl-a
  6. 6.BNla Lake — Chautauqua County5.2 ft clarity · 18 µg/L P · 4 µg/L chl-a
  7. 7.BLake Crawford — Crawford County5.1 ft clarity · 0 µg/L P · 13 µg/L chl-a
  8. 8.BLeavenworth Co State Fishing Lake — Leavenworth County4.3 ft clarity · 12 µg/L P · 15 µg/L chl-a
  9. 9.BNew Yates Center Lake — Woodson County5.2 ft clarity · 0 µg/L P · 13 µg/L chl-a
  10. 10.BMadison City Lake — Greenwood County4.1 ft clarity · 0 µg/L P · 8 µg/L chl-a

Most-polluted lakes

Lowest combined water-quality score among monitored lakes.

  1. 1.FGathering Pond East — Geary County1.0 ft clarity · 440 µg/L P · 186 µg/L chl-a
  2. 2.FMilford Lake Sugar Bowl — Clay County0.4 ft clarity · 2790 µg/L P · 309 µg/L chl-a
  3. 3.FNla Lake — Kingman County0.6 ft clarity · 154 µg/L P · 62 µg/L chl-a
  4. 4.FNla Lake — Sedgwick County0.2 ft clarity · 430 µg/L P · 231 µg/L chl-a
  5. 5.FBig Eleven Lake Park Lake — Wyandotte County2.8 ft clarity · 147 µg/L P · 45 µg/L chl-a
  6. 6.FMcpherson Co State Fishing Lake — McPherson County1.8 ft clarity · 260 µg/L P · 100 µg/L chl-a
  7. 7.FChisholm Creek Park Lake South — Sedgwick County1.1 ft clarity · 205 µg/L P · 97 µg/L chl-a
  8. 8.FHarvey Co East Lake — Harvey County1.0 ft clarity · 360 µg/L P · 205 µg/L chl-a
  9. 9.FBuhler City Lake — Reno County1.3 ft clarity · 830 µg/L P · 520 µg/L chl-a
  10. 10.FHiawatha City Lake — Brown County2.1 ft clarity · 135 µg/L P · 93 µg/L chl-a

Worst algae hotspots

Highest measured chlorophyll-a (algae) concentration.

  1. 1.FWakefield Boat Ramp Milford Lake — Clay County133000 µg/L chlorophyll-a
  2. 2.FNorth Lake — Clay County76500 µg/L chlorophyll-a
  3. 3.FTimber C Boat Ramp Milford Lake — Clay County1910 µg/L chlorophyll-a
  4. 4.FRiggs Park Lake — Sedgwick County1700 µg/L chlorophyll-a
  5. 5.FColwich City Lake — Sedgwick County800 µg/L chlorophyll-a
  6. 6.CMarais des Cygnes Wildlife Area Lake — Linn County602 µg/L chlorophyll-a
  7. 7.FCarbondale West Lake — Osage County552 µg/L chlorophyll-a
  8. 8.FBuhler City Lake — Reno County520 µg/L chlorophyll-a
  9. 9.FMilford Lake Sugar Bowl — Clay County309 µg/L chlorophyll-a
  10. 10.FMarais des Cygnes Nwr Lake — Linn County255 µg/L chlorophyll-a

Explore Kansas 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 Kansas lakes.

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