So when people say "my water bill is higher than $X", do they mean the combined bill? Does the town I live in just have abnormally high water prices for an area without water scarcity, or is water just artificially cheap in other places?
Regarding the former - Yes. It's basically something like this:
line 1 - Water usage = X
line 2 - Sewage usage = X * modifier
My monthly water usage is usually something like $20 worth, but my "water bill" is usually around $60-$65 when combining water + sewage (2 adults, $ = USD).