Idaho Code § 42-212: Diversion of private waters.

The department of water resources is hereby prohibited from issuing or granting permits to divert or appropriate the waters of any lake not exceeding five (5) acres in surface area at highwater mark, pond, pool or spring in this state, which is located or situated wholly or entirely upon the lands of a person or corporation, except to the person or corporation owning said land, or with his or its written permission, executed and acknowledged as required for the conveyance of real estate.