STORMWATER 101: How Will Rates Be Assessed?

Sinkholes, such as this one found off Walnut Avenue, are just one of the many negative impacts of unmanaged stormwater and often result in significant private property damage.

Previously, we have discussed what stormwater is, what types of damage it causes and how to successfully address stormwater management. Stormwater runoff is created when rain hits impervious surfaces (hard or solid surfaces like pavement, concrete, roofs, etc. that water cannot penetrate). This runoff picks up pollutants as it goes, like oil and grease, harmful bacteria, fertilizers, toxic chemicals and other contaminants which are harmful to people, water quality and aquatic life.

Stormwater management is handled by a stormwater utility which is a single entity established to address stormwater management and stormwater-related issues like flooding, water quality and erosion.

How Stormwater Rates Are Calculated

A property’s contribution to stormwater runoff is directly correlated to the amount of impervious surfaces. The amount of impervious surface is used to calculate stormwater rates.


A sampling of residential properties in the City of Dalton has been evaluated to come up with a median square footage of impervious surfaces (roofs, driveways, etc.). This “equivalent residential unit” (ERU) value equals 3,700 sq. ft. This rate will apply to all residential units, resulting in a proposed stormwater rate of $3 per month ($36 per year) per residence.


The amount of impervious surface (roofs, parking lots, etc.) for businesses, churches, retail shops, grocery stores, industrial facilities, governmental buildings, multi-family housing, etc. will be calculated individually using Dalton Utilities’ Geographic Information System (GIS) which is accurate to +/- one foot. The GIS is a high-tech mapping system which uses aerial photography and global positioning system (GPS) technology to provide a very accurate map of each property. Once a property is measured for total impervious surface in the GIS system, the rate for each business parcel will be calculated using the ERU (or 3,700 sq. ft. = $3). For instance, the rate for a business location with a measurement of 37,000 sq. ft of impervious surface would be divided by 3,700 sq. ft (the ERU) to arrive at the sum of 10. This sum would then be multiplied by the $3 value equaling a stormwater rate for this business parcel of $30 per month.

In the future, we will discuss specific services and the timeline for implementation of stormwater services and customer billing. For more information on stormwater runoff and stormwater management, please visit