| Nippersink Creek Near Spring Grove, IL |
| North Branch Chicago River At Albany Avenue At Chicago, IL |
| North Branch Chicago River At Deerfield, IL |
| North Branch Chicago River At Grand Avenue At Chicago, IL |
| North Branch Chicago River At Niles, IL |
| North Fork Embarras River Near Oblong, IL |
| North Fork Vermilion River Near Bismarck, IL |
| North Mill Creek At Hickory Corners, IL |
| North Mill Creek Near Milburn, IL |
| North Shore Channel At Wilmette, IL |
| Ohio River At Dam 51 At Golconda, IL |
| Ohio River At Dam 53 Near Grand Chain, IL |
| Ohio River At Metropolis, IL |
| Ohio River At Olmsted, IL |
| Pecatonica River At Freeport, IL |
| Pecatonica River Near Shirland, IL |
| Plum Creek Near Crete, IL |
| Pope Creek Near Keithsburg, IL |
| Poplar Creek At Elgin, IL |
| Rayse Creek Near Waltonville, IL |
| Richland Creek Near Hecker, IL |
| Robinson Creek Near Shelbyville, IL |
| Rock River Above Sinnissippi Dam At Rock Falls, IL |
| Rock River At Auburn St At Rockford, IL |
| Rock River At Byron, IL |
| Rock River At Como, IL |
| Rock River At Dixon, IL |
| Rock River At Latham Park, IL |
| Rock River At Rockton, IL |
| Rock River Near Joslin, IL |
| Saline Branch Above 1700E Near Urbana, IL |
| Salt Creek At 22Nd Street At Oak Brook, IL |
| Salt Creek At Elmhurst, IL |
| Salt Creek At Higgins Rd Near Elk Grove Village, IL |
| Salt Creek At Rolling Meadows, IL |
| Salt Creek At Western Springs, IL |
| Salt Creek At Wood Dale, IL |
| Salt Creek Near Elk Grove Village, IL |
| Salt Creek Near Greenview, IL |
| Salt Creek Near Rowell, IL |
| Salt Fork Near St. Joseph, IL |
| Sangamon River At Fisher, IL |
| Sangamon River At Monticello, IL |
| Sangamon River At Petersburg, IL |
| Sangamon River At Riverton, IL |
| Sangamon River At Route 48 At Decatur, IL |
| Sangamon River Near Oakford, IL |
| Sangamon River Near Springfield, IL |
| Sawmill Creek Near Lemont, IL |
| Senachwine Creek At Chillicothe, IL |
