The superintendent of streets shall, upon the entering of a decree of court directing a reassessment or upon the making of an order by the legislative body directing a reassessment, proceed to make a reassessment in the following manner:
(a)
If the reassessment is a partial one only, then it shall not be necessary for the diagram to show any other lots than the ones covered by such partial reassessment.
(b)
If it is a full reassessment, the superintendent of streets shall prepare and file with the reassessment a diagram showing the lots or parcels of land deemed by him to have been benefited by the work. The reassessment shall assess upon and against each of the lots or parcels of land contained therein an amount arrived at as follows:
The benefits derived, or to be derived, by each of the lots or parcels of land from the work estimated as of the date of the filing in the clerk’s office of the original assessment shall first be listed. Then there shall be added thereto interest thereon from 30 days after the date of such filing of the original assessment at the rate of 7 percent per annum, and the total sum shall constitute and be the amount of the proposed several assessments in such reassessment. The total of such reassessment, however, exclusive of interest, shall not exceed the cost and expenses of the work.
In the event such reassessment is not confirmed within seven months of the date of filing in the clerk’s office of the original assessment, the legislative body shall pay from its general funds the 7 percent interest added to the cost and expenses of the work in accordance with this section, plus the incidental expenses of such reassessment in the event that a reassessment is made.