Why do we pay a monthly storm water fee?

According to the United States Environmental Protection Agency (EPA), urbanized areas have the greatest potential to pollute storm water runoff.   EPA established National Pollutant Discharge Detection and Elimination (NPDES) MS4 Phase II regulations in 2003 requiring municipalities over 10,000 in population or that have had a large percentage of population growth between the 1990 and 2000 census, to develop storm water quality management plans (Phase I regulations enacted in 1990 apply to populations over 100,000 like Indianapolis).  This regulation was enacted as an unfunded mandate.  Decatur developed a Storm Water Quality Management Plan (SWQMP) that states our goals and objectives for minimizing pollutants in storm water runoff.  In order to cover the costs of implementing the plan, Decatur established storm water fees for residents and commercial/industrial property owners.

I don’t have storm sewers serving my property.  Why am I being charged this fee?

Every property contributes and places a demand on the storm water system.  Every property benefits from the City’s Storm Water Utility/MS4 Program activities, whether or not there is a constructed storm sewer connected directly to the property.  The City of Decatur’s vast storm water conveyance system consists of both natural and constructed features, many of which are not obvious.  In addition to the traditional storm sewer system, the MS4 conveyance system includes roads, ditches, swales, and culverts. Under the federal MS4 mandate, the City must manage the entire storm water system, which includes providing water quality protection, conveyance system mapping, water sampling and testing, watershed planning, public education and outreach, and other programs for the benefit of the entire community.

I was informed that my bill is based on my property’s “impervious surface”.  What is an “impervious surface"?

It is the area on a property that is covered by buildings, driveways, parking areas, and other hard surfaces (concrete, gravel, asphalt, roof-tops) that prevent storm water runoff from being absorbed into the soil.  Consequently, storm water runoff picks up pollutants deposited on these hard surfaces, such as oil, gasoline, pesticides, and other chemicals and carries them to our waterways.  In addition, as runoff travels over these hard surfaces, it gains speed and erodes soil near or in these water bodies, adding another pollutant called sediment. 

Storm Water Fees Explained

The amount of impervious surface (hard surfaces such as roads, buildings, driveways, and parking lots) is the factor taken into consideration to determine an equitable storm water fee.

Fees are determined using a base rate and an Equivalent Residential Unit or ERU assessed on every parcel.  An ERU is a unit value, which is equal to the average amount of impervious surface area for a single-family home within the MS4 Program jurisdiction.  One (1) ERU has been determined to equal 2840 square feet of impervious surface area. Based on the annual budget of the storm water utility the user fee basic rate has been set @ $1.80 per month. This is the amount single-family dwellings pay. Non-residential property user fees are determined by dividing their total amount of impervious surface area by 2840 then multiplying that number by $1.80.

    Non-residential property storm water fee example: impervious surface = 22,720 sq. feet

                                                                                           22,720 ÷ 2,840 = 8

                                                                                           8 X 1.80 = $14.40 monthly storm water fee