Stormwater Basics

What is stormwater runoff?

Rainfall that does not soak into the ground, but instead flows over the land into creeks, streams, rivers or lakes is called runoff, stormwater runoff, or just stormwater.



What is a watershed?

Watershed illustration A watershed is all the land area that drains to a given body of water. Every stream, river and lake has a watershed. Everything that takes place within a watershed can affect what happens to our streams, rivers and lakes.



Why be concerned about stormwater?

Waterfall

Stormwater runoff occurs naturally, but as development and the amount of impervious surfaces such as rooftops, roads and parking lots increase in a watershed, the natural capacity of the soil and vegetation to infiltrate and take up rainfall decreases, and more rainfall becomes stormwater runoff. This can produce negative impacts such as streambank erosion and flooding.

In addition, stormwater runoff can easily pick up pollutants such as dirt, oil and grease, chemicals, nutrients, metals, and bacteria as it runs off the land and carries them to the nearest river or stream. This can result in water quality impairments which can affect human uses as well as aquatic life.

Because rivers and lakes are the primary source of drinking water in north Georgia, stormwater and watershed protection is something that everyone needs to be aware of.


How do we address the negative impacts of stormwater runoff?

There are a number of ways to address the impacts of stormwater runoff.  These include:

  • Requiring post-construction structural stormwater controls—for both runoff quantity and quality—on all new development and redevelopment projects
  • Encouraging better site design to reduce imperviousness and leave more land as greenspace
  • Promoting pollution prevention practices to help keep contaminants out of stormwater
  • Addressing illicit discharge and illegal connections to storm sewer systems
  • Providing for stream buffer protection and effective floodplain management