How to Calculate Your Water Bill

Our 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 Centum (hundred) cubic feet. One Ccf equals 748 gallons. To convert Ccf to gallons, multiply by 748.  Ex.  6 Ccf  x  748  =  4,488 gallons

  2. Water connection size
    Find it on your bill. Most residential customers have a 3/4 inch connection.

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

Calculate your water bill:

  1. Determine your minimum bill
    Most residential customers 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 1/1/2026
    Connection Size: 3/4 inch    
    Minimum Bill Inside City: $17.25    
    Minimum Bill Outside City: $27.80

    Connection Size: 1 inch
    Minimum Bill Inside City: $21.50
    Minimum Bill Outside City: $32.60

    Connection Size:  1 1/2 inches
    Minimum Bill Inside City:     $42.20
    Minimum Bill Outside City:     $55.20

    Connection Size: 2 inches
    Minimum Bill Inside City:     $57.40
    Minimum Bill Outside City:     $71.90

    Connection Size: 3 inches
    Minimum Bill Inside City:     $124.25
    Minimum Bill Outside City:     $145.50

    Connection Size: 4 inches
    Minimum Bill Inside City:     $200.25
    Minimum Bill Outside City:     $228.50

    Connection Size: 6 inches
    Minimum Bill Inside City:     $390.00
    Minimum Bill Outside City:     $437.00

    Connection Size: 8 inches
    Minimum Bill Inside City:     $579.50
    Minimum Bill Outside City:     $646.00

    Connection Size: 10 inches
    Minimum Bill Inside City:     $770.00
    Minimum Bill Outside City:     $854.50

    Connection Size:  12 inches
    Minimum Bill Inside City:     $883.50
    Minimum Bill Outside City:     $979.00
     
  2. Determine how much water you used above the 2 Ccf minimum bill amount
     If you used 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

    Calculate the volume charge
    Find the appropriate unit rate (inside or outside City) and multiply by the amount of water you calculated in step 2.

    Rates effective 1/1/2026
    Water Use: Over 2 Ccf
    Inside City of Charleston: $2.68 Ccf
    Outside City of Charleston: $4.99 per Ccf
Continuing the example from above, if the customer lives inside city of Charleston with a 3/4 connection, calculate volume charge like this:

2026 Rates  4 Ccf  x  $2.68  =  $10.72 (volume charge)

Add the volume charge to the minimum bill
This will give you 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:

$17.25 (minimum bill) + $10.72 (volume charge) = $27.97 (total water bill) (2026 rates)