Idaho Code § 42-403
Proof of completion of works under such permit shall be made in accordance with the laws of the state of Idaho relative to proof of completion under a permit to appropriate the public waters of the state of Idaho, as to all works of diversion under such permit: provided, that the department of water resources may as a condition to the issuance of a certificate of completion under such proof require from the officer or official mentioned in section 42-401 a certificate to the effect that the proper public records of such sister state show the works to have been completed under said permit, said certificate to show in second feet the capacities of the various conduits constructed and to show in acre feet the capacities of reservoir, if any there be, constructed in such sister state under said permit.
Idaho Code § 42-403