| Rank | Rivers | Lakes | Estuaries |
| 1 | Agriculture | Agriculture | Industrial Discharges |
| 2 | Municipal Point Sources | Unspecified Nonpoint Sources | Urban Runoff/Storm Sewers |
| 3 | Hydrologic Modification | Atmospheric Deposition | Municipal Point Sources |
| 4 | Habitat Modification | Urban Runoff/Storm Sewers | Upstream Sources |
| 5 | Resource Extraction | Municipal Point Sources | Agriculture |
|