Idaho Code § 40-811
No special tax or charge shall be made by a highway district against land within a special tax district until the highway has been completed to within at least one (1) mile of all the land within the special tax district, the highway has been accepted by the district board, the cost certified, and all the proceedings taken as specified. All interest payable on the bonds up to that time shall be paid by the highway district without imposing on the special tax district a special tax other than its share in the taxation of the highway district as a whole. After the special tax has been levied the highway district board shall in each year, at the same time of the tax levy to meet the interest requirements of bonds, also levy a special tax on the land within every special tax district then created, in an amount sufficient to pay the interest for that year on the portion of the bond issue, the indebtedness which shall have been charged against the special tax district. Whenever the highway district board shall levy a tax to meet any principal or sinking fund requirement of the bonds, they shall at the same time levy a special tax on the land within every special tax district an amount sufficient to pay the principal or sinking fund requirements for that year on the portion of the bond issue, the indebtedness of which shall have been charged against the special tax district. All special taxation within any single special tax district shall be of a uniform amount per acre within the special tax district. Each installment of principal or sinking fund tax collected from the taxation of any land within a special tax district shall be credited on the original assessment of special tax made, and where all the installments shall have been paid, the special assessment shall be deemed canceled, paid and discharged. No special tax district shall ever be called upon to pay as special taxes any sum greater than the amount charged against the district or the land in the original special assessment and proportionate share of interest. In making the levy for the requirements of the bonds, the highway district board shall levy on the district at large only an amount of taxes in each year as shall be required to meet the requirements for that year of that portion of the bond issue which has not been charged against the special tax districts. Should the levy together with the levies on special tax districts in any year fail to produce sufficient funds to meet the obligation of the highway district on the whole issue, then the deficiency shall be paid out of the other revenues of the highway district, and if necessary, the bond levy shall be increased in the following year to make good that deficiency. No failure or delay on the part of the highway district in imposing, levying or collecting the special taxes shall, as between the district and the bondholders, impair the obligation of the highway district upon the whole of the bonds.
Idaho Code § 40-811