How is the Stormwater Utility charge calculated?
Currently, a stormwater fee is collected through a uniform volume rate structure based on amount of metered water usage. This approach simplified billing. However, potable water usage is completely unrelated to the issue of stormwater runoff. A more fair and equitable basis for calculating stormwater charges is the amount of a property’s impervious area which can be measured and has a direct and accepted relationship to the estimated amount of water that leaves a property as stormwater runoff. A property’s impervious area is the most significant factor affecting both stormwater quality and quantity because stormwater cannot be absorbed by these surfaces and must be managed through some sort of stormwater system. A unit of impervious surface area on an average single family, residential property, or “equivalent residential unit” (ERU), is the quantity used for assessing the new stormwater charges. The size of one ERU was determined by averaging the impervious surface areas existing on a
