Cleanest Lakes in Iowa
West Okoboji Lake in Dickinson County leads the rankings with a water quality grade of A and 15.7 ft of clarity. Below are the top 50 cleanest monitored lakes in Iowa, ranked by EPA water quality score.
Ranked List
| # | Lake | County | Grade | Clarity | Phosphorus | Algae |
|---|---|---|---|---|---|---|
| 1 | West Okoboji Lake | Dickinson | A | 15.7 ft | 20 µg/L | 2.3 µg/L |
| 2 | Dale Maffitt Reservoir | Dallas | A | 9.8 ft | 20 µg/L | 2.1 µg/L |
| 3 | Blue Pit Lake | Cerro Gordo | A | 17.1 ft | 20 µg/L | 2.4 µg/L |
| 4 | Ada Hayden Heritage Park Lake | Story | A | 6.8 ft | 19 µg/L | 5.2 µg/L |
| 5 | Little Sioux Park Lake | Woodbury | A | 5.7 ft | 19 µg/L | 5.7 µg/L |
| 6 | Rudd Lake | Floyd | A | 8.1 ft | 14 µg/L | 4.5 µg/L |
| 7 | Slipbluff Lake | Decatur | A | 9 ft | 17.5 µg/L | 4.5 µg/L |
| 8 | Lacey Keosauqua Lake | Van Buren | A | 7.1 ft | 21.5 µg/L | 4.7 µg/L |
| 9 | Yenruogis Pond | Keokuk | A | 9.9 ft | 21 µg/L | 6.2 µg/L |
| 10 | Sand Lake | Marshall | A | 6.4 ft | 25 µg/L | 3.6 µg/L |
| 11 | Terra Park Lake | Polk | A | 11.5 ft | 20 µg/L | 4.7 µg/L |
| 12 | Storm Lake Max Depth | Buena Vista | B | 1.7 ft | 123.5 µg/L | 11 µg/L |
| 13 | Arrowhead Lake | Sac | B | 5.6 ft | 26 µg/L | 7.1 µg/L |
| 14 | Kent Park Lake | Johnson | B | 4.8 ft | 25 µg/L | 11.4 µg/L |
| 15 | Mariposa Lake | Jasper | B | 5.1 ft | 31 µg/L | 8.9 µg/L |
| 16 | Mormon Trail Lake | Adair | B | 6.2 ft | 25 µg/L | 9.7 µg/L |
| 17 | Newell Pit Lake | Buena Vista | B | 4.1 ft | 37 µg/L | 11.9 µg/L |
| 18 | Bob White Lake | Wayne | B | 0.6 ft | 264 µg/L | 10.1 µg/L |
| 19 | Willow Lake | Harrison | B | 4.8 ft | 35 µg/L | 9.5 µg/L |
| 20 | Poll Miller Park Lake | Lee | B | 5.9 ft | 28 µg/L | 7.7 µg/L |
| 21 | Lake Minnewashta | Dickinson | C | 2.8 ft | 47 µg/L | 19 µg/L |
| 22 | Upper Gar Lake | Dickinson | C | 3.9 ft | 52.5 µg/L | 13.1 µg/L |
| 23 | Railroad Lake | Scott | C | 5.1 ft | 44.5 µg/L | 8.3 µg/L |
| 24 | Big Spirit Lake | Dickinson | C | 5.5 ft | 55 µg/L | 16.3 µg/L |
| 25 | Mitchell Lake | Black Hawk | C | 2.3 ft | 40.5 µg/L | 18.7 µg/L |
| 26 | Lost Grove Lake | Scott | C | 3.9 ft | 31 µg/L | 15.8 µg/L |
| 27 | Blue Grass Lake | Scott | C | 4.5 ft | 63 µg/L | 12.7 µg/L |
| 28 | Oldham Lake | Monona | C | 5.1 ft | 46 µg/L | 8.5 µg/L |
| 29 | Rathbun Lake | Appanoose | C | 3 ft | 48 µg/L | 15.3 µg/L |
| 30 | Green Belt Lake | Black Hawk | C | 2.4 ft | 57 µg/L | 18.6 µg/L |
| 31 | Green Castle Lake | Marshall | C | 4.6 ft | 59 µg/L | 6.9 µg/L |
| 32 | Lake Petocka | Polk | C | 3.3 ft | 39.5 µg/L | 9.3 µg/L |
| 33 | Lake of the Hills | Scott | C | 5.1 ft | 53 µg/L | 16.8 µg/L |
| 34 | Lambach Lake | Scott | C | 7.9 ft | 63 µg/L | 5.1 µg/L |
| 35 | Stolley Pit Lake | Clay | C | 2.7 ft | 48 µg/L | 17.3 µg/L |
| 36 | Thomas Mitchell Lake | Polk | C | 3.3 ft | 87 µg/L | 13.2 µg/L |
| 37 | Lost Island Lake | Palo Alto | D | 2.6 ft | 68 µg/L | 19.1 µg/L |
| 38 | Nodaway Lake | Adair | D | 2.8 ft | 57 µg/L | 27.6 µg/L |
| 39 | Clear Lake | Cerro Gordo | D | 2.1 ft | 52 µg/L | 26.4 µg/L |
| 40 | Pleasant Creek Lake | Linn | D | 3.6 ft | 38 µg/L | 26.5 µg/L |
| 41 | Hooper Pond Lake | Warren | D | 2.5 ft | 61 µg/L | 25.1 µg/L |
| 42 | Lower Gar Lake | Dickinson | D | 2.6 ft | 71.5 µg/L | 20.7 µg/L |
| 43 | Manteno Lake | Shelby | D | 2.7 ft | 138.5 µg/L | 28.3 µg/L |
| 44 | Lake Cornelia | Wright | D | 2.5 ft | 37 µg/L | 20.1 µg/L |
| 45 | Hawthorn Lake | Mahaska | D | 2.4 ft | 60 µg/L | 27.5 µg/L |
| 46 | Yellow Smoke Lake | Crawford | D | 3 ft | 56.5 µg/L | 21.6 µg/L |
| 47 | Easter Lake | Polk | D | 2.9 ft | 49.5 µg/L | 22.8 µg/L |
| 48 | Three Mile Lake | Union | D | 2.7 ft | 43 µg/L | 28.4 µg/L |
| 49 | East Okoboji Lake | Dickinson | D | 3.9 ft | 56 µg/L | 25.3 µg/L |
| 50 | Lake Macbride | Johnson | D | 2.9 ft | 59 µg/L | 28.5 µg/L |
More Answers for Iowa
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