There's no way to give an exact answer to how much your water bill might be.
The amount your water bill will be each month depends on your water rates, where you're located and how much water you actually use.
The more water you use per month the higher your water bill will be and the less water you use per month the lower your water bill will be.
My water bill averages $50.00 per month but that includes the sewer and trash bill as well.
The water cost itself is around $25.00 per month.