| Upper Iowa River At Decorah, IA |
| Upper Iowa River At Kendallville, IA |
| Upper Iowa River At Lime Springs, IA |
| Upper Iowa River Near Dorchester, IA |
| Volga River At Fayette, IA |
| Volga River At Littleport, IA |
| Walnut Creek At Des Moines, IA |
| Walnut Creek Near Hartwick, IA |
| Wapsipinicon River At Independence, IA |
| Wapsipinicon River At Oxford Mills, IA |
| Wapsipinicon River Near Anamosa, IA |
| Wapsipinicon River Near De Witt, IA |
| Wapsipinicon River Near Tripoli, IA |
| Waterloo Creek Near Dorchester, IA |
| West Fork Cedar River At Finchford, IA |
| West Fork Ditch At Hornick, IA |
| West Main Drainage Ditch 1 And 2 Near Britt, IA |
| West Nishnabotna River At Hancock, IA |
| West Nishnabotna River At Randolph, IA |
| West Nishnabotna River Near Riverton, IA |
| White Breast Creek Near Dallas, IA |
| Willow Creek Near Soldier, IA |
| Winnebago River At Mason City, IA |
| Wolf Creek Near Dysart, IA |
| Yellow River Near Ion, IA |
