In this subtitle the following words have the meanings indicated. “Expanded water appropriation permit” means a revised permit granting a significant increase in the withdrawal of water authorized under the existing water appropriation permit. “Public water system” has the meaning stated in § 9–401 of this article and is a water system located in the State. “Water conservation” means the use of practices, techniques, and technologies that: Reduce the consumption, loss, or waste of water; Improve efficiency in the use of water; or Make more efficient use of water treatment infrastructure.