Charleston Water System's operations are funded by revenue from water and sewer bills. Therefore, our rates are structured to recover operating costs and fund capital improvements.
Charleston Water retains a rate consultant to ensure our rates meet cost recovery requirements and follow industry standards. Rate increases are approved by our Board of Commissioners.
Notice: Water and sewer rates increased an average of 4.5% and 5.5%, respectively on December 1, 2011. More info
Rate Schedules
A series of three rate increases was approved by Charleston Water's Board of Commissioners in September 2010, along with the 2011 - 2013 Capital Improvement Program. Click below to download the rate schedules (PDF).
2011 Rates
Effective 12/1/2010 - 11/30/2011
2012 Rates (Current Rates)
Effective 12/1/2011 - 11/30/2012
2013 Rates
Effective 12/1/2012
About Our Water Rates
Your water bill is calculated based on three things:
- The size of your water service connection
- Where you live (inside or outside the City of Charleston)
- How much water you use each month above the 1,500 gallons (2 Ccf) minimum bill.
Connection Size
The diameter of your water service line (the line between your water meter and home/business) affects your rate because larger pipes carry more water and place a greater demand on the system. Most homes and small businesses have a three-quarter-inch service. Commercial buildings that have a high water demand, such as hotels and industrial facilities, can have a service line up to twelve inches in diameter.
Where You Live
Customers who live inside the City of Charleston pay lower rates. Why? Charleston Water System is a public utility owned by the citizens of the City of Charleston. When Charleston Water borrows money to fund infrastructure, it is the citizens of Charleston who bear the risk of the debt and new infrastructure.
Because of this risk, rates for customers outside of the City are calculated to include return on investment and depreciation of assets, resulting in a higher rate. This is a standard practice in utility rate setting, and many large utilities that provide service to areas outside of their municipal bounds follow this rationale.
Monthly Water Consumption
Charleston Water System has a minimum bill, 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, a specific rate is charged for each additional Ccf.
Even if you don't use any water, Charleston Water must still have infrastructure in place to make service available to you and provide fire protection. The minimum bill recovers these costs, as well as costs associated with administrative services like meter reading and billing.
How to calculate your bill
Dedicated Fire Service
Dedicated fire services are connections to the public water system that are only used for fire protection. These water service lines are typically connected to a building's fire sprinkler system. There is no connection fee for the installation of a dedicated fire service, but there is a monthly rate determined by the pipe size, as shown in the table below.
Rate Schedule for Private Fire Protection
Effective December 1, 2011 |
Tap (pipe)Size |
Monthly Charge
Inside City |
Monthly Charge
Outside City |
| 4 inch or less |
$7.75 |
$10.00 |
| 6 inch |
$22.92 |
$29.50 |
| 8 inch |
$48.75 |
$62.50 |
| 10 inch |
$87.58 |
$113.00 |
| 12 inch |
$141.67 |
$182.00 |
About Our Sewer Rates
Who's your sewer provider?
Charleston Water System only provides sewer service to areas within the city of Charleston, unincorporated areas in West Ashley, parts of Johns Island, and the Cainhoy peninsula.
For CWS water customers outside of these areas, public sewer service is provided by one of the following utilities:
Charleston Water System is the billing agent for some of these sewer providers (you'll see this noted on your bill), but we do not set rates or manage the sewer infrastructure for these agencies.
Charleston Water System's Sewer Rates
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. Charleston Water System charges a minimum sewer bill for the first 3 Ccf and a specific rate for each additional Ccf.
For single-family residential customers that do not have an irrigation meter, sewer charges are based on 95% of metered water usage. Residential sewer customers who receive their water service from St. Johns Water Company are billed for sewer based on 100% of water usage.
For multi-family residential customers, single-family residential customers with an irrigation meter, and commercial customers, sewer charges are based on 100% of water usage.
Non-Metered Flat Rate
Customers who receive water service from a private well and sewer service from Charleston Water System are charged a flat rate for sewer. This is because without metered water service, there is no way to measure sewer usage. The monthly flat rate is $45.29 for customers inside the City of Charleston and $62.96 for those outside the city limits.
Sewer Cap for Residential Customers
Single family residential customers without an irrigation meter will not be billed for sewer on water usage above 18 Ccf (13,500 gallons). This is the maximum sewer charge (sewer cap).
Irrigation Meters
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. Learn more about irrigation meters.
Other Rates and Charges
Wholesale Water Service
In addition to providing retail water service to some 107,000 accounts, Charleston Water System also wholesales water to a number of utilities and municipalities in the greater Charleston area, including:
- Mt. Pleasant Waterworks
- St. Johns Water Company (serves Kiawah and Seabrook Islands)
- Dorchester County Public Works
- Town of Folly Beach
- Town of Sullivan's Island
- Isle of Palms Water & Sewer Commission
- Town of Lincolnville
Wholesale Wastewater Treatment Service
In addition to retail sewer service, Charleston Water System 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. |
