Idaho Code § 42-231
In addition to other duties prescribed by law, it shall be the duty of the director of the department of water resources to conduct investigations, surveys and studies relative to the extent, nature and location of the ground water resources of this state; and to this end, the director of the department of water resources may, on behalf of the state of Idaho enter into cooperative investigations, researches, and studies with any agency or department of the government of the United States, or any other state or public authority of this state, or private agencies or individuals. It shall likewise be the duty of the director of the department of water resources to control the appropriation and use of the ground water of this state as in this act provided and to do all things reasonably necessary or appropriate to protect the people of the state from depletion of ground water resources contrary to the public policy expressed in this act.
Idaho Code § 42-231