off topic but an interesting issue

The large issue with snakes is their ability to thrive outside of their natural habitat. They were once thought to survive only in sub-tropical climates, but it has been found that this is not the case. Apparently there are large pythons living in the sewer systems of places like New York, which theoretically gets too cold in the winter for these guys. The issue is a non-native species outcompeting native species and causing problems.
The real issue is idiots who buy an animal that gets too big for them and then decide to let it go free.
I understand your issue with the vicinity of where you live, but allow me to give you another analogy. When I was in school for my BS, we were a hop, skip, and a jump away from Mexico. We were very close; simply walking across the border would have us under a whole new set of laws, but that doesn't change the fact that just because I was on one side of the line versus the other that I wasn't bound by the laws wherever I was standing. Of course, this is an extreme case, but if laws are allowed to be bent (and unfortunately they are, which is a problem), at what point do you really draw the line? Somebody SOMEWHERE is going to live just outside of this line, no matter where you draw it.

 

I question snakes in the sewers, but there are lots of really big pythons thriving in the Everglades. They will displace and/or eradicate many native species before long.

It may be that some municipalities want to eliminate any gray areas so they ban all exotic pets in order to prevent people getting hold of the harmful ones.

 

I am basing what I said on researchers actually finding large snakes in the cobblestone waterways (may not be sewers, but I call them that) in New York. They are also being found in the wild far more north than Florida and Georgia, in places where temps drop lower than what we might expect them to survive. Larger snakes seems to be far more capable of tolerating drops in temperature (although underground, temps even in the winter supposedly can stay about 70 degrees in places like NY).
I do agree keeping a snake that is native to the state should be legal. It is likely they are just trying to put a blanket law over everything, just to keep there from being issues where some "authority" doesn't know what species of snake you have. I am also uncertain myself about the laws of keeping wildlife. They could very easily ban a snake that is native to your area from being kept caged under the grounds that wildlife may not be kept as pets (again, in CA, where I grew up, this was the case, not so sure about here in IA).

 

http://www.extension.iastate.edu/Publications/IAN604.pdf

There's a nice pdf of snakes native to Iowa (go to page 16)

 

The problem here is your sampling size. How many snakes have you kept? 1? 10? 1000? All of those numbers are far too small a sample size to say with an acceptable degree of certainty that they will not survive. If even a fraction of a percent can (and apparently do) survive, those animals breeding is what produces more animals with the traits necessary to survive in such conditions. From there, you have the start of a potentially invasive species. Plenty of non-native animals have been introduced all over the world and don;t necessarily become an invasive species. The problem is that in many cases it can be tough to tell unless it's too late.

 

Yeah and let's not forget in Florida the bermes python has taking the state over and they say at the rate it is growing they will take over most of the south

 

I'm pretty sure you can have snakes in CR as long as they are not constrictors. That being said, it's illegal to own colubrids or eliapidaes also, and for good reason. Other than constrictors or venomous snakes I'm not sure what your options are. I hope you can see the value in illegalizing the posession of some animals for practical reasons; venmous, dangerous, or endangered.

However none of these reasons really apply to the outlaw of constrictor species, and I suspect it's much less because of ledgitamet concerns over ecological issues effecting Iowa. Frankly, snakes in sewer systems is by-and-large hearsay and probably nothing more than ubran ledgends, if any such event had occured, they're certainly rare, and New York has a massive subterranian steam and infastructure system reaching more than 500 feet below the streets, that's the only explaination I could conjure for those types of tall tales.

The current law in CR is likely due to irrational fears of individuals on the city council or ordinance comittee.