Rates Overview

Charleston Water System's operations are funded by revenue from water and sewer bills. Our rate structure is designed to recover costs and fund capital improvements. This is critical to our long-term financial and operational sustainability.

We retain a rate consultant to ensure that our rates meet cost recovery requirements and follow industry standards. Rate increases are approved by our Board of Commissioners.

Rate Structure
There are a number of different rate structures designed to meet the varying cost recovery needs of utilities. This is because operating costs can differ drastically from utility to utility based on factors such as the quality and quantity of source water, treatment processes, infrastructure age and condition, service area geography and size, climate, and customer demographics.

Charleston Water System has a uniform volumetric rate structure with a minimum bill and inside/outside city rate classes.

The minimum bill covers costs that do not vary with customers' water use, such as metering and billing and making service available 24-7 (including for fire protection).

Customers who live outside of the City of Charleston pay higher rates. This is because Charleston residents own the system and bear the risk of extending infrastructure outside the City limits. Because of this risk, outside-city rates are calculated to include return on investment and depreciation of assets, which results in higher rates. 

It's a similar concept to purchasing a rental property and charging rent that is higher than the monthly mortgage as a return on investment. This is standard practice in utility rate setting. Large utilities that provide service to areas outside of their municipal bounds follow this rationale.

How We Measure Water Use
Our water meters measure water use in cubic feet (cf), but our rates are based on units of 100 cubic feet, abbreviated Ccf.

  • 1 cubic foot = 7.48 gallons
  • 100 cubic feet = 1 Ccf 
  • 1 Ccf = 748 gallons
  • To covert Ccf to gallons, multiply by 748. For example:
    3.25 Ccf x 748 = 2,431 gal
How We Measure Sewer Use
Sewer use is calculated based on water use.