My water bill has fixed charges for access to the water system and an "impervious surface" charge for storm water runoff. plus the actual usage.
A CCF is "100 cubic foot of water" or 748 gallons.
I used to use 4 CCF a month, I've gotten it down to 1 or 2 now. But yeah, every once in a while I succeed in preventing the meter from moving one CCF increment and all I paid was fixed charges.