Iowa Code § 468.77: Maturity — interest — highway benefits.

The board shall fix the amount, maturity, and interest of all bonds to be issued. It shall determine the amount of assessments to highways for benefits within the district to be covered by each bond issue. The taxes levied for benefits to highways and other public lands within any drainage or levee district shall be paid at the same times and in the same proportion as assessments against the lands of private owners.