| Lake | County | Latitude | Longitude |
| Three Mile Reservoir | 41.088790 | -94.231453 | |
| Timber Lake | Johnson | 41.819924 | -91.672676 |
| Town Lake | Jackson | 42.082360 | -90.181909 |
| Trickle Slough | Dickinson | 43.498155 | -95.059319 |
| Trumbull Lake | Clay | 43.192967 | -94.951737 |
| Tuttle Lake | Emmet | 43.494638 | -94.593456 |
| Twelve Mile Reservoir | 41.072100 | -94.267330 | |
| Twelvemile Lake | Emmet | 43.289814 | -94.874373 |
| Twin Lake | Johnson | 41.816923 | -91.626245 |
| Twin Lakes | Jackson | 42.187878 | -90.322013 |