Sorry to filibuster here, but more hopefully-useful thoughts:
Think about how chickens can add value to the community, or are at least value-neutral.
Many municipalities are strapped for cash these days, and even if they aren't, City Councils
love new revenue sources and they really don't like things that cost money.
I point this out because that's why I listed the things I did in my prior post for you to address. All of these things are ways chickens could cost the community money.
With this in mind, crafting an ordinance that includes permitting fees and fines is a good way to offset costs.
Say, there's a $50 permitting fee for keeping no more than 6 mature hens, 8 pullets, or 12 sexed female chicks at a time. Describe the necessary housing facilities per mature hen. I'd say a free-range ban isn't necessary, since rooster-less flocks that wander around freely aren't going to last long anyway, what with predators. However, you can include it so that people aren't given nightmares of chickens pooping on their Lexus.
Example: fines might be $75 for first-time infractions, $150 for second time, and a $500 fine for third infractions plus a lifetime ban on owning chickens. I'm just making up these numbers, but you want to make it so that it stings enough to prevent people from doing it, but not so high that the municipality might be tempted to use it as a source of tasty income by over-policing chicken owners.
Keeping a rooster incurs a fine
and the mandatory confiscation and destruction of the rooster.
While you might shrink from the "mandatory destruction" bit, the trouble with more humane options, like just surrendering the bird to animal control, is that this tends to result in the local animal shelter filling up with unwanted roosters, especially around three months after easter. That's a cost to the public. We don't want costs associated with resolving ordinance infractions, so unless the fine is steep enough to include the costs of caring for a rooster for the course of its natural life, it's probably easiest to just have the roos euthanized upon confiscation.
Recommend the definition of "rooster" for the ordinance, otherwise it will be invented by the City, and that can get weird. We know that different breeds can be sexed by certain ages, and that some take longer than others to crow, but a Council left to their own devices might define a rooster as "a male chicken that has reached 8 weeks of age" or something equally not useful. An easy definition is a male chicken that crows.
I'd consider including a ban on caponization, too. Not that backyard chickeneers do much of that in the US, but it's an easy giveaway that shows goodwill and humane concern for the critters.
If it were me, I'd throw in a ban on gamefowl breeds. Another easy giveaway that prevents questions about cock fighting. Otherwise, there's not much cause to get into breed-specific bans/allowances.
If people are concerned with diseases, you might propose that permitting includes mandatory testing for Pullorum-Typhoid, like the USDA requires for people who will sell birds for food:
https://agr.wa.gov/foodanimal/avianhealth/pullorumtyphoid.aspx In this case, the permitting fee should include the cost of having the birds tested, otherwise people probably won't comply. Think of it like having your dog vaccinated for rabies.
Changing gears here: when I suggested making a list of communities with these ordinances and tracking property values, I forgot to suggest that you compare the property values post-chicken-allowance to the average increase in property values for similarly situated communities. Without a "control group" to compare it to, you can't really tell if the chickens had an effect. City councils love this kind of data. Especially charts and graphs.
Okay, that's all I have for real this time.
Good luck!
