Understanding Stormwater in Avondale Estates

What happens to all the rain that falls? Much of it soaks back into the ground replenishing our streams and waterways and feeding our plants and natural ground cover. But what about the rest of the stuff that does not soak back into the ground?

Stormwater Drain

What is Stormwater?

Stormwater is precipitation that cannot soak into impervious areas such as paved streets, parking lots, and building rooftops during rainfall events. Because it cannot soak into the ground, it “runs off” the land into neighboring waterways. Stormwater runoff often contains pollutants in quantities that could adversely affect water quality. Stormwater pollution from point sources and nonpoint sources is a challenging water quality problem. Unlike pollution from industry or sewage treatment facilities, which is caused by a discrete number of sources, stormwater pollution is caused by a discreter number of sources, stormwater pollution is caused by the daily activities of people everywhere. Rainwater runs off streets, lawns, farms, as well as construction and industrial sites. It then picks up fertilizers, dirt, sediment, pesticides, oil and grease, and many other pollutants on the way to streams, rivers, and lakes. Stormwater runoff is the most common cause of water pollution.

What is Stormwater Management?

Stormwater management is the process of changing land use practices in the built landscape to maintain the quality, quantity, and rate of runoff as close to the predevelopment condition as possible. This includes preventing runoff at the source by minimizing the number of hard surfaces; providing areas to detain water and slow its progress toward the streams; amending soils to absorb more water; constructing filtration areas with vegetation to filter water as it moves across the land; and practicing good housekeeping both day-to-day and on construction sites to prevent sediment and other pollutants from washing into streams.

Why is Stormwater Management Important?

In areas that do not have man-made impermeable surfaces, precipitation normally takes a long time to reach a stream. A small amount of waterfalls on the stream surface, but most of the water reaches the stream only after it has soaked into the ground and moved through the soil. When impermeable surfaces are added to a watershed, the water reaches the stream very quickly and in much larger quantities than the stream is used to. In addition, urban areas are normally serviced by a system of pipes and catch basins which are designed to get water off the land as quickly as possible and convey it to the stream. This excessive volume of water is more than the channel can handle and erosion of the channel results. When the channel erosion occurs, it caused cloudy (turbid) water that negatively affects the organisms in the stream and the downstream users of the water, in addition to destroying habitat. It is, therefore, important to prevent runoff at the source wherever possible.

What can residents do?

The public has an important role to play as well. The program’s success depends on the support and involvement of citizens. Become an informed participant in voluntary conservation and preservation initiatives and learn how you can help.

Illicit Discharges 

The EPA defines an illicit discharge as any discharge to the municipal separate storm sewer system (MS4) that is not composed entirely of stormwater, except for discharges allowed under an NPDES permit or waters used for firefighting operations.  Since the City of Avondale Estates holds an MS4 permit, we’re required to have an illicit discharge detection and elimination program.  

What is an Illicit Discharge? 

Examples include the dumping of motor fluids, household hazardous wastes, grass clippings, leaf litter, industrial waste, restaurant waste, or any other non-stormwater waste. An illicit connection is the discharge of pollutants or non-stormwater material into a stormwater system via a pipe or other direct connection.

How do you identify an illicit discharge or connection?

Examples are makeshift pipes or hoses that lead to a storm drain or body of water; stains, unusual odors, structural damage to streets or gutters; and abnormal vegetative growth in nearby lakes and streams.

How do you report an illicit discharge?

As a resident of Avondale Estates, a business person, or a general user of our facilities, you are encouraged to report any problems you see or experience with stormwater facilities and infrastructure. Please contact Kristin Moretz  (404-823-2427).        



  • Dispose of grass clippings and other yard debris by placing it curbside on the designated days; better yet, start a compost
  • Don’t discard household hazardous waste like paint, cleaning fluids or gasoline into sinks or toilets
  • Reduce runoff by landscaping instead of paving
  • Use pesticides and fertilizers sparingly and only in the recommended amounts
  • Don’t dump motor oil, antifreeze, or other chemicals down the storm drain; recycle them whenever possible
  • Wash your car at a commercial car wash that treats and recycles its wastewater
  • When walking your pet, remember to pick up pet waste and dispose of it properly so harmful bacteria don’t wash into storm drains.