Idaho Code § 18-4309
Every person who shall willfully waste water for irrigation, or who shall willfully open, close, change or disturb, or interfere with, any headgate or water box or valve or measuring or regulating device, without authority, shall be guilty of a misdemeanor. The water masters or their assistants, within their district, shall have power to arrest any person or persons offending and turn them over to the sheriff or the nearest peace officer of the county in which such offense is committed, and immediately upon delivering such person so arrested into the custody of either of such officers, it shall be the duty of the water master making such arrest to make complaint, in writing and under oath, before the magistrate judge of such county, against the person so arrested.
Idaho Code § 18-4309