Cities are provided three options under Iowa law for maintaining their city codes.  These include:

1. The city may compile an annual supplement to the code of ordinances.  This supplement consists of all new ordinances and amendments to ordinances that became effective during the previous year.  The supplement must be adopted by resolution by the council and placed in the code of ordinances. 

2.  The city may insert new ordinances or amendments to ordinances directly into the code itself.  This must be done at least annually.  This works especially well for cities that maintain a copy of their city code in electronic format, allowing for quick and convenient updating.  

3.  If the city does not take either of the actions described above, it must codify the code of ordinances at least once every five years.  If there have been no substantive changes to the city code, the city may simply adopt the code by ordinance.  However if the city has made additions, amendments or intends to change any code provision, it must hold a public hearing on the proposed code prior to its adoption.  

Waterloo utilizes option two for the city code and option three for the traffic code.  City Clerk's Office staff have been working this year to incorporate numerous amendments into the traffic code and have now made it available on the city website for easy public access.  The public hearing and ordinance adopting the updated traffic code are required in order to maintain a valid and enforceable traffic code. 

The traffic code is found on the City Clerk's Office page of the city website, under the section titled Code of Ordinances. 

Link: https://www.cityofwaterlooiowa.com/government/city_clerks/index.php