I'm not an expert on this- chlorine is really not good for them OR us, but it depends on how much (how noticeable) it is where you live, I suppose? I'd love to know
more about this too, actually...but all these years my snakes have been drinking the same tap as I do. Granted, I don't live in Flint MI...and as the water sits in
their bowl, I believe the chlorine off-gases, or so I've read. Where I live the required water test results (they're required to furnish yearly) are pretty good.