The City charges both a fixed monthly service charge and a water use or “volumetric” rate. The fixed service charge is based on the size of a meter and is a flat sum due each month without respect to water use. All Single Family Residential users pay the same monthly charge because the small differences among 5/8”, 3/4” and 1-inch meters do not justify different rates. The water use, or volumetric rate, is calculated by multiplying the rate by the number of gallons a customer uses (in 1,000 gallon units or “kgals”) in a billing period.