Levy of assessments

(1) After the assessment roll is in final form and is so confirmed by resolution, the urban district by the same or by a supplemental resolution shall by reference to such assessment roll as so modified, if modified, and as confirmed by such resolution, levy the assessments in the roll. (2) The board shall cause the resolution levying the assessments to be published at least one time in a newspaper of general circulation in the improvement district. (3) No assessment shall be levied for any capital improvements acquired by the urban district and located or to be located on any land until the board by the adoption of such resolution or otherwise determines that the district has the right to possession of such land or an interest therein for the purpose of acquiring the improvements. (4) Such decision and resolution shall be a final determination of the regularity, validity, and correctness of the proceedings, of the assessment plat, of the assessment roll, of each assessment contained therein, and of the amount thereof levied on each tract. (5) Such determination by the board shall be conclusive upon the owners of the property assessed. (6) The roll shall be prima facie evidence in all courts and tribunals of the regularity of all proceedings preliminary to the making thereof and of the validity of the assessments and the assessment roll.