Idaho Code § 43-404
Whenever the electors shall have authorized an issue of bonds as hereinbefore provided, the board of directors shall examine each tract or legal subdivision of land in said district, and shall determine the benefits which will accrue to each of such tracts or subdivisions from the construction or purchase of such irrigation works; and the cost of such works shall be apportioned or distributed over such tracts or subdivisions of land in proportion to such benefits; and the amount so apportioned or distributed to each of said tracts or subdivisions shall be and remain the basis for fixing the annual assessments levied against such tracts or subdivisions in carrying out the purpose of this chapter.
Such board of directors shall make, or cause to be made, a list of such apportionments or distribution, which list shall contain a complete description of each subdivision or tract of land of such district, with the amount and rate per acre of such apportionment or distribution of cost, and the name of the owner thereof; or they may prepare a map on a convenient scale showing each of said subdivisions or tracts with the rate per acre of such apportionment entered thereon: provided, that where all lands on any map or section of a map are assessed at the same rate, a general statement to that effect shall be sufficient.
Said list or map shall be made in duplicate and one (1) copy of each shall be filed in the office of the department of water resources and one (1) copy shall remain in the office of said board of directors for public inspection.
Whenever thereafter any assessment is made either in lieu of bonds, or any annual assessment for raising the interest on bonds, or any portion of the principal, it shall be spread upon the lands in the same proportion as the assessment of benefits, and the whole amount of the assessment of benefits shall equal the amount of bonds or other obligations authorized at the election last above-mentioned.
Idaho Code § 43-404