Idaho Code § 42-213

All applications to the department of water resources for permits to divert or appropriate the waters of any lake, pond, pool or spring shall state whether such lake, pond, pool or spring is wholly or entirely upon the land of any person or corporation other than the applicant, and, in the event that it is, such application shall state that the applicant has the written permission from such owner, executed and acknowledged as required by the provisions of the preceding section to divert or appropriate such water.