| Abbreviation | Definition |
|---|---|
| NOHRSC | National Operational Hydrologic Remote Sensing Center |
| OA | Operation Analysis |
| OIHD | Ontario Integrated Hydrology Dataset |
| ORA | Ontario Rivers Alliance |
| OREP | Office of Reservoir Evaluation and Production |
| PF | Precipitation-Frequency |
| PFD | Peak Flood Discharge |
| PHG | Palestinian Hydrology Group |
| PMP | Probable Maximum Precipitation |
| PPTF | Pounds Per Thousand Feet |
| PSP | Pumped Storage Project |
| RDII | Rainfall-Derived Inflow and Infiltration |
| RE | Renewable Energy |
| RGMC | Reform Gravel Mining Coalition |
| RHEM | Rangeland Hydrology and Erosion Model |
| RID | Roza Irrigation District (Washington state) |
| SA | Spillway Apron (hydopower station) |
| SG | Spillway gate (Hydropower station) |
| SIM | Sonar Interface Module |
| SOH | Subcommittee On Hydrology |