How to Calculate Your Water Bill

Your water bill includes the following 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'll pay an additional volume charge. To determine your minimum bill and volume charge, you need to know three things:

  1. How much water you used 
    This is listed 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. Your water connection size
    This is also listed on your bill. Your connection size determines your minimum bill. This is because larger connection sizes place a greater demand on the water system. (Residential customers typically have a 3/4-inch connection size.)

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

About our water rates
Learn more about our rate structure and view current and past rate schedules here.

Here's how to calculate your water bill:

  1. Determine your minimum bill
    Use the table below to find your minimum bill based on your water connection size and whether you live inside or outside the City of Charleston. Residential customers typically have a 3/4-inch connection. If you used between 0 and 2 Ccf of water, you will only pay the minimum bill amount. If you used more than 2 Ccf, continue to step 2.

        Residential customer inside the City of Charleston 
        $12.25 minimum bill

     Connection Size Minimum Bill
    Inside City

    Minimum Bill
    Outside City

     3/4 inch  $12.25  $19.35
     1 inch  $14.95  $22.45
     1 1/2 inches  $26.90  $35.90
     2 inches  $36.20  $46.40
     3 inches  $76.00  $91.50
     4 inches  $121.25  $142.50
     6 inches  $236.00  $272.00
     8 inches  $349.50  $400.50
     10 inches  $463.50  $529.00
     12 inches  $531.50  $606.00
    Rates effective 1/1/2016

  2. Determine how much water you used above the 2 Ccf minimum
    For example, if you used a total of 6 Ccf, the first 2 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 based on whether you live inside or outside the City of Charleston and multiply by the amount of water you calculated in step 2. 

     Water Use   Inside City Rate Outside City Rate
    Over 2 Ccf  $1.70 per Ccf  $3.24 per Ccf
    Rates effective 1/1/2016

    Continuing the example from above, if the customer lives inside City of Charleston, she would calculate her volume charge like this:

               4 Ccf  x  $1.70  =  $6.80 (volume charge)

  4. Add the volume charge to the minimum bill

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

         $12.25 (minimum bill)  +  $6.80 (volume charge)  =  $19.05 (total water bill)