Idaho Code § 43-1828
Pursuant to the provisions of section 6 of said reclamation extension act, if said operation and maintenance charge or assessment is paid on or before the date when due there shall be a discount of five per cent (5%) of such charge, but if such charge is unpaid on the first day of the third calendar month thereafter a penalty of one per cent (1%) of the amount unpaid shall be added thereto, and thereafter an additional penalty of one per cent (1%) of the amount unpaid shall be added on the first day of each calendar month if such charge and penalties shall remain unpaid and no water shall be delivered to the land of any landowner or entryman who shall be in arrears for more than one (1) calendar year for the payment of any charge for operation and maintenance, or any annual construction charge and penalties. In districts coming under this act the penalties herein provided shall, in the matter of such district operation and maintenance assessments, be a substitute for and take the place of the penalties and interest provided in section 4401 of Idaho Compiled Statutes.
Idaho Code § 43-1828