StateMod allows water use efficiency to vary from 0 to a user specified maximum value. See Section 7.3 for additional discussion on how to implement variable efficiency in a model. The following are noted:
- Variable efficiency uses the Modified Direct Solution Algorithm (Bennett, Ray R., December 2000).
- Variable efficiency requires consumptive water requirement data be provided for every diversion and well only structure by year. If not provided, it is estimated from the average efficiency data provided in the diversion and well station (*.dds and *.wes) files and demand data.
- Variable efficiency for wells may include a value for both flood and sprinkler applications if the acres served by sprinklers are provided.
- Variable efficiency operations may include soil moisture accounting although it is not required.
- Variable efficiency capability applies to all direct diversion, well pumping and carrier to diversion structure operations.
- Variable efficiency capability does not apply to reservoir releases. These operating rules continue to use the average efficiency data provided in the diversion station file (*.dds) to determine the structure’s demand from the reservoir.