Note: US Customary units apply when CFS, GPM, AFD, or MGD is chosen as flow units. SI Metric units apply when flow units are expressed using either liters or cubic meters.
| PARAMETER | US CUSTOMARY | SI METRIC |
|---|---|---|
| Concentration | mg/L or μg/L | mg/L or μg/L |
| Demand | (see Flow units) | (see Flow units) |
| Diameter (Pipes) | inches | millimeters |
| Diameter (Tanks) | feet | meters |
| Efficiency | percent | percent |
| Elevation | feet | meters |
| Emitter Coefficient | flow units / (psi):sup:1/2 | flow units / (meters):sup:1/2 |
| Energy | kilowatt - hours | kilowatt - hours |
| Flow | CFS (cubic feet / sec) GPM (gallons / min) MGD (million gal / day) IMGD (Imperial MGD) AFD (acre-feet / day) |
LPS (liters / sec) LPM (liters / min) MLD (megaliters / day) CMH (cubic meters / hr) CMD (cubic meters / day) |
| Friction Factor | unitless | unitless |
| Hydraulic Head | feet | meters |
| Length | feet | meters |
| Minor Loss Coeff. | unitless | unitless |
| Power | horsepower | kilowatts |
| Pressure | pounds per square inch | meters |
| Reaction Coeff. (Bulk) | 1/day (1st-order) | 1/day (1st-order) |
| Reaction Coeff. (Wall) | mass / L / day (0-order) ft / day (1st-order) |
mass / L / day (0-order) meters / day (1st-order) |
| Roughness Coefficient | 10-3 feet (Darcy-Weisbach), unitless otherwise | millimeters (Darcy-Weisbach), unitless otherwise |
| Source Mass Injection | mass / minute | mass / minute |
| Velocity | feet / second | meters / second |
| Volume | cubic feet | cubic meters |
| Water Age | hours | hours |