Iowa Code § 412.3: Rules.

The council, board of waterworks trustees, or other board or commission, whichever is authorized by law to manage and operate such waterworks, or other municipally owned and operated public utility, may formulate and establish such pension and annuity retirement system, and may make and establish such rules for the operation thereof as may be deemed necessary or appropriate, subject to the provision of section 412.2, subsection 1.