Our rate structure

Charleston Water System’s rates are established using industry standards, and are verified by a nationally recognized consulting firm.  This ensures our rates are financially sound and adequately support our ability to maintain infrastructure, expand our system to meet growing demand, and meet regulatory requirements. 

View rate schedule and learn how to calculate your bill


Rate Increases
Because Charleston Water System’s revenue comes exclusively from water and wastewater rates, rate increases are necessary to pay for new infrastructure. In 2006, Charleston Water's Board of Commissioners approved a three-year rate increase to repay debt incurred by a bond issue to fund our Capital Improvement Program.

The next rate increase will take effect on December 1, 2008. Water rates will increase by an average of 4%; wastewater rates will go up by an average of 7%.

Rate increase fact sheet (PDF)
2008 rate schedule, effective Dec. 1, 2007 (PDF)
2009 rate schedule, effective Dec. 1, 2008 (PDF)

About Your Water Bill
Your monthly bill is calculated according to where you live (inside or outside Charleston City limits), the size of the water line feeding your home or business, and your water usage.

Charleston Water System has a minimum bill structure, meaning all customers pay a minimum monthly water bill for 2 Ccf of usage (1,500 gallons), regardless of whether the entire 2 Ccf is used. After the first 2 Ccf, Charleston Water System charges a specific rate for each additional Ccf.

Water rates

Charleston Water System’s rates for water use are based on three factors: 1.) the size of the pipe that connects to your house, 2.) where you live, and 3.) how much water you use each month.  In addition, Charleston Water charges a minimum bill regardless of water consumption.  All of these items are described below.

• The Minimum Bill

  Regardless of monthly consumption, all customers are charged a monthly minimum rate.  Why?  Even if you use no water at all, Charleston Water System must still read your meter, send you a bill, and generally make the service available to you.  By charging a minimum bill, we are able to recoup the costs associated with making water and sewer service available to our customers.

• Pipe size

  Also called connection size or tap size, the diameter of the service line to your home or business determines the amount of your minimum bill.  This is because larger pipes carry more water, and have a greater overall impact on the water system.  Most homes have a three-quarter-inch service line, but some businesses, such as hotels and large office buildings, may have a service line up to twelve inches in diameter. 
  

• Where you live 

Your minimum bill, as well as your per-unit consumption charge, is based on where you live.  Charleston Water System is a publicly owned utility, technically owned by the citizens of the City of Charleston.  When we borrow money to make improvements to our infrastructure, it is the citizens of Charleston who are technically responsible for this debt.  In addition, the cost of extending service to areas outside of the City limits adds cost.  As a result, our rate structure includes slightly higher charges for residents and businesses outside the Charleston City limits.

• Your monthly water consumption
  The final factor that influences your water bill is the most obvious—how much water you use.  Our water meters measure how much water enters your home or business in cubic feet (cf).  One cubic foot is equal to 748 gallons.  For simplification, our rates are based on one hundred cubic feet, abbreviated Ccf.

Our minimum bill charges the same amount for any consumption up to 2 Ccf.  That means that all of our customers are charged for 200 cubic feet of water consumption, which equals 1,496 gallons—even if they use less that that amount.  

If you use more than 2 Ccf of water—which most people do—you are charged for each additional Ccf (one hundred cubic feet) you use.  If the cubic feet and hundred cubic feet measurements are confusing, you can easily convert the numbers to gallons, by multiplying Ccf by 748 gallons.  For example, 9.36 Ccf of consumption would be 7,001 gallons (9.36 x 748 = 7,001.28).

Dedicated fire services
Dedicated fire services are connections to the public water system that are only used for fire protection. These water services are typically connected to a building's fire sprinkler system.

On July 24, 2007, our Board of Commissioners approved a separate monthly rate for dedicated fire service accounts, and eliminated the tap and impact connection fees for the installation of these services. The monthly charges for dedicated fire services are listed below. Click here to view press release with more information.

Rate Schedule for Private Fire Protection Approved and effective on July 24, 2007
Tap (pipe)Size	Connection Fee	Monthly Charge (Inside & Outside City)
4 inch or less	$0	$7.75
6 inch	$0	$22.92
8 inch	$0	$48.75
10 inch	$0	$87.58
12 inch	$0	$141.67

 

Sewer Rates

Charleston Water System’s sewer rates are based on water consumption.  This is because the majority of water you use goes down drains and toilets and ends up in the sewer system. Because we realize that not all water ends up in our sewer system—many people water their lawns and wash their cars—sewer charges are based on 90% of water usage.  Charleston Water System charges a minimum sewer bill for the first 3 Ccf and a specific rate for each additional Ccf

Sewer Cap

The sewer cap simply means that we set a limit on residential sewer charges.  Regardless of how much water you use, you will not incur sewer charges for any amount above 18 Ccf (13,500 gallons) of water usage.

Irrigation meter

Charleston Water System offers separate irrigation meters for customers who use a high volume of water for irrigation purposes.  Irrigation meters are not charged for sewer.

Non-metered flat rate
Customers who received sewer service from Charleston Water System but not water service are charged a flat rate. This is because without metered water service, there is no way to measure sewer usage. Therefore, the flat rate is based on 6 Ccf (4,500 gallons) of flow and the monthly charge is $35.47 for customers inside the City of Charleston and $49.37 for those outside the city limits. This rate affects a small number of customers who either receive water service from another provider or have private wells.

Other rates and charges

The 2008 wholesale water service rate (effective Feb. 1, 2008) is $1.69/Ccf for municipalities and $1.91/Ccf for subdivisions.

• Dorchester Water Authority
• Dorchester County Water & Sewer
• Town of Folly Beach
• Town of Lincolnville
• St. John’s Water Company
• Kiawah Island Utilities (via St. John’s Water Company)
• Seabrook Island Utility Commission (via St. John’s Water Company)

The purchased capacity rates apply to wholesale water customers who pay three separate charge components which are: (1) a capital buy-in charge, (2) an annual capital charge, and (3) a volumetric rate. Effective July 1, 2007, the water volumetric rates are as follows:

• Isle of Palms Water & Sewer Commission -- $0.51/Ccf
• Mt. Pleasant Waterworks -- $0.41/Ccf
• Town of Sullivan’s Island -- $0.93/Ccf
  

Wastewater Treatment Service
In addition to retail sewer service, Charleston Water System also provides treatment services to several municipalities in the Greater Charleston area, including the towns of Folly Beach, Hollywood, Ravenel, and Meggett. This means that wastewater generated from these areas flows through a master meter and is treated at Charleston Water System’s plant, but Charleston Water System does not provide direct service to customers in those areas.