Idaho Code § 42-211
Whenever a permit has been issued pursuant to the provisions of this act, and the permit holder desires to change the place, period, or nature of the intended use, or make other substantial changes in the method of diversion or proposed use or uses of the water, he shall file an application for amendment upon forms to be furnished by the department of water resources together with the statutory fee for filing and recording same, and upon receipt thereof it shall be the duty of the department of water resources to examine same and if approval thereof would not result in the diversion and use of more water than originally permitted and if the rights of others will not be adversely affected thereby, the director of the department of water resources shall approve said application and return an approved copy to the permit holder. The director of the department of water resources shall give such notice to other affected water users as he deems appropriate and may grant the amendment, in whole or in part or upon conditions, or may deny same. Notice of partial approval or conditions or denial of an amendment shall be forwarded to the applicant by certified mail and shall be subject to judicial review as hereafter provided. The priority of the right established pursuant to a permit which has been amended under these provisions shall date from the date of the original application for permit, provided the permit holder has complied with other provisions of this act.
In connection with any application on which permit has not been issued, amendments may be made by indorsement by the applicant or his agent on the original application, which indorsement shall be initialed and dated. If the amendment will result in the use of more water than originally asked, the priority of the right shall be changed to the date of said amendment. The applicant shall also be required to pay any additional filing fee as a result of an amendment of the rate of diversion or volume of storage requested in such amended application. If amendment is made after publication of notice of the original application, said notice shall be republished following amendment, upon payment by the applicant of the statutory fee for republication as in this act provided.
The notice shall be published in the same manner as provided by section 42-203, Idaho Code, for publication of notice of an application for permit. Protests to the application for amendment may be filed with and heard by the director in the same manner as provided by section 42-203, Idaho Code, for protests to an application for a permit.
If a protest is filed and a hearing on the protest held, any person aggrieved by the final decision of the director following the hearing may seek judicial review thereof pursuant to section 42-1701A(4), Idaho Code.
If no protest is filed and the director grants the amendment in part or on conditions or rejects the amendment without a hearing, the applicant may request a hearing pursuant to section 42-1701A(3), Idaho Code, for the purpose of contesting the action of the director and following the hearing and the issuance of a final decision by the director may seek judicial review thereof pursuant to section 42-1701A(4), Idaho Code.
Idaho Code § 42-211