How to Calculate Your Water Bill

Your water bill includes these charges:

     Minimum Bill  +  Volume Charge   =  Total Water Bill
All customers pay the minimum bill, which includes up to 2 Ccf (1,496 gallons) of water. If you use more than 2 Ccf, you pay an additional volume charge. To determine your minimum bill and volume charge, you need to know three things:

  1. Water used 
    This is on your bill in a unit called Ccf, which stands for hundred cubic feet. 1 Ccf equals 748 gallons. To convert Ccf to gallons, multiply by 748.
          Example:   6 Ccf  x  748  =  4,488 gallons

  2. Water connection size
    Find it on your bill. Residential customers typically have a 3/4 inch connection. Larger connections place a greater demand on the system.

  3. Whether you live inside or outside the City of Charleston
    This affects your minimum bill and volume charge.

Water rates

Learn more about rate structure and view current/past rate schedules here.

Calculate your water bill:

  1. Determine your minimum bill
    Residential customers typically have a 3/4 inch connection. If you used between 0 and 2 Ccf of water, you only pay the minimum bill amount. If you used more than 2 Ccf, continue to #2 below.

    Rates effective 1/1/2018
     Connection Size Minimum Bill
    Inside City

    Minimum Bill
    Outside City

     3/4 inch  $12.60  $19.95
     1 inch  $15.40  $23.10
     1 1/2 inches  $27.70  $35.90
     2 inches  $37.30  $37.00
     3 inches  $78.25  $94.25
     4 inches  $125.00  $146.75
     6 inches  $243.00  $280.00
     8 inches  $360.00  $412.50
     10 inches  $477.50  $545.00
     12 inches  $547.50  $624.00

  2. Determine how much water was used above the 2 Ccf minimum
    f you use 6 Ccf, the first 2 Ccf are included in the minimum bill. That means you'll pay a volume charge for the other 4 Ccf. 

           6 Ccf (total usage)  -  2 Ccf (included in minimum bill)  =  4 Ccf 

  3. Calculate the volume charge
    Find the appropriate unit rate and multiply by the amount of water you calculated in step 2.

     Water Use   Inside City of Charleston
    Outside City
    Over 2 Ccf  $1.76 per Ccf  $3.36 per Ccf
    Rates effective 1/1/2018

    Continuing the example from above, if the customer lives inside city of Charleston, calculate volume charge like this:
    2018 Rates                        4 Ccf  x  $1.76  =  $7.04 (volume charge)

  4. Add the volume charge to the minimum bill

    This is your total water bill. Here's what it would look like for a residential customer who lives in the City of Charleston and used 6 Ccf (4,488 gallons) of water:

         $12.60 (minimum bill)  +  $7.04 (volume charge)  =  $19.64 (total water bill)