It shall be the further duty of the engineer and viewers to personally examine the land in the district and classify it with reference to the benefit it will receive from the construction of the levee, ditch, drain, or watercourse or other improvement. In the case of drainage, the degree of wetness on the land, its proximity to the ditch or a natural outlet, and the fertility of the soil shall be considered in determining the amount of benefit it will receive by the construction of the ditch. The land benefited shall be separated in five classes. The land receiving the highest benefit shall be marked "Class A"; that receiving the next highest benefit, "Class B"; that receiving the next highest benefit, "Class C"; that receiving the next highest benefit, "Class D," and that receiving the smallest benefit, "Class E." The holdings of any one landowner need not be all in one class, but the number of acres in each class shall be ascertained, though its boundary need not be marked on the ground or shown on the map. The total number of acres owned by one person in each class and the total number of acres benefited shall be determined. The total number of acres of each class in the entire district shall be obtained and presented in tabulated form. The scale of assessment upon the several classes of land returned by the engineer and viewers shall be in the ratio of five, four, three, two, and one; that is to say, as often as five mills per acre is assessed against the land in "Class A," four mills per acre shall be assessed against the land in "Class B," three mills per acre in "Class C," two mills per acre in "Class D," and one mill per acre in "Class E." This shall form the basis of the assessment of benefits to the lands for drainage purposes. In any district lands may be included which are not benefited for the agriculture or crop production, or slightly so, but which will receive benefit by improvement in health conditions, and as to such lands the engineer and viewers may assess each tract of land without regard to the ratio and at such a sum per acre as will fairly represent the benefit of such lands. Villages or towns or parts thereof and small parcels of land located outside thereof and used primarily for residence or other specific purposes, and which require drainage, may also be included in any drainage district which by reason of their improved conditions and the limited area in each parcel under individual ownership, it is impracticable to fairly assess the benefits to each separated parcel of land by the ratio herein provided, and as to such parcels of land the engineer and viewers may assess each parcel of land without regard to the ratio and at a higher rate per acre respectively by reason of the greater benefits. If the streets or other property owned by any incorporated town or village are likewise benefited by such drainage works, the corporation may be assessed in proportion to such benefits, which assessment shall constitute a liability against the corporation and may be enforced as provided by law.
The board of viewers may determine that some areas of the district will receive more benefits than other areas and if such is determined, the varying benefits shall be reflected in the manner of classification of benefits to each area and the tracts of land therein. (1909, c. 442, s. 12; C.S., s. 5329; 1923, c. 217, s. 1; 1961, c. 614, s. 7.)