Idaho Code § 43-501

In any irrigation district now organized or hereafter to be organized, for any portion of the time from the time said bonds begin to bear interest until five (5) years after the irrigation works of such district have been completed and water used in the irrigation of the lands in such district, in lieu of paying the interest on said bonds by revenues derived from the assessments on the lands in the district, the board of directors may pay any part of such interest with the proceeds of the sale of coupon bonds of such district to be issued and sold by them for said purpose.