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LakeQuality

Safest Lakes to Swim In in Illinois

17 lakes in Illinois qualify as safest for swimming, all hold grade A or B and report chlorophyll-a (algae) under 10 µg/L. Always check local advisories on the day you swim.

Ranked List

#LakeCountyGradeClarityPhosphorusAlgae
1Axehead LakeCookA11.9 ft10 µg/L-
2Powderhorn LakeCookA10.1 ft13 µg/L-
3Baumann Park LakeWinnebagoA10.2 ft11.5 µg/L-
4Silver LakeMcHenryB7 ft11 µg/L-
5Boulder South LakePerryB8.8 ft14.5 µg/L-
6Wampum LakeCookB6.9 ft16 µg/L-
7Round LakeLakeB7.4 ft19.5 µg/L-
8Big Rock LakeKaneB8.1 ft10 µg/L-
9Flatfoot LakeCookB6.3 ft10.5 µg/L-
10Opeka LakeCookB3.9 ft15.5 µg/L-
11One Horse Gap LakePopeB4 ft17 µg/L-
12Glendale LakePopeB4.8 ft16 µg/L-
13Tecumseh LakeHardinB3.6 ft18 µg/L-
14Grays LakeLakeB3.5 ft18 µg/L-
15Calumet LakeCookB4.3 ft10.5 µg/L-
16Lily LakeMcHenryB3.3 ft16 µg/L-
17Catherine LakeLakeB7.4 ft27.5 µg/L-

More Answers for Illinois