Idaho Code § 57-222
The governing board of the issuing corporation shall levy and cause to be levied annually at the time when and in the manner in which other general taxes of such issuing corporation are levied, upon all the taxable property within its limits, in addition to all other authorized taxes and assessments, a tax or assessment sufficient to meet the payments of principal and interest on such bonds as the same mature, and to constitute a sinking fund for the payment of the principal amount of said bonds within thirty (30) years from the time of contracting the indebtedness evidenced thereby and in accordance with the provisions made for the payment of the principal and interest of such bonds and also to constitute a sinking fund for the payment of the principal thereof, as theretofore provided by ordinance or by resolution and as required by the constitution and law of Idaho; and such taxes shall be levied, assessed, certified, extended and collected by the proper officers and at the times, all as fixed by law and as other taxes are levied, assessed, certified, extended and collected in, for and by the issuing corporation and by the same officers thereof until the principal and interest of all such bonds and interest thereon shall be fully paid. All of such taxes when collected shall be credited by the proper receiving officers to separate funds distinct from the funds for the payment of principal or interest on bonds of any other series or issue, and apart from any other funds of the issuing corporation.
Idaho Code § 57-222