the choice of flow units. One of: "EN_CFS", "EN_GPM", "EN_MGD",
"EN_IMGD", "EN_AFD", "EN_LPS", "EN_LPM", "EN_MLD", "EN_CMH", "EN_CMD"
Details
Flow units in liters or cubic meters implies that SI metric units
are used for all other quantities in addition to flow. Otherwise US Customary
units are employed.