In this chapter, the following terms have the meanings indicated. Terms Defined. “Consumptive water use” means that portion of a water withdrawal which, as a result of evaporation, interbasin diversions, or other means, is not returned to the source to be available for subsequent use. “Department” means the Department of the Environment. “Low flow augmentation” means the provision of water, through development of new water storage facilities or the purchase of storage space in existing water storage facilities or both, equal to the amount of consumptive use.