Iowa Code § 468.587
A county may issue special assessment bonds in anticipation of the collection of special assessments for the cost of drainage improvements within a district in the same manner as provided for cities under subchapter IV of chapter 384.
85 Acts, ch 144, §1 CS85, §331.487 89 Acts, ch 126, §2 CS89, §468.587 2018 Acts, ch 1041, §127