What is Stormwater Runoff?

Stormwater runoff is rainwater that does not soak into the surface on which it falls, but rather runs along the surface downhill. It is commonly associated with urban areas because of the increase in impervious surfaces (rooftops, driveways, roads), which impede water from infiltrating (or soaking into) the ground. Stormwater picks up and carries pollutants, like sediment, trash, toxins, nutrients and pathogens, to our streams and rivers.

Excess stormwater also can result in flooding and damage to municipal infrastructure, such as roadways, greenways, and sanitary sewers.  

Why is Stormwater a Big Deal?

Contrary to common belief, stormwater issues are often associated with average rainfall events, not just with major rainstorms. Areas that exist naturally and are undisturbed by urban development are less likely to be affected by the negative impacts of stormwater runoff. Areas of development and human-activity are prone to significant issues related to stormwater runoff. Developed areas of land have a lower infiltration rate due to the addition of impervious surfaces like parking lots, sidewalks, etc. This instead causes the rainfall to flow over land surfaces and into our storm drains and streams, carrying pollutants along with it. Stormwater pollutants are things like sediment, trash, chemicals and oil, and other debris, both natural and unnatural. We can prevent these pollutants from entering the storm drains and waterways and slow down water flow by creating and maintaining buffer/riparian areas. Examples of these prevention techniques are planting trees, enhancing wetlands, installing rain gardens and inlet protection, and other landscaping projects that can increase water infiltration into the soil. To learn more about how you can implement these techniques, click here.

Managing Stormwater

It is essential to manage stormwater runoff to help prevent flooding and pollution. There are a variety of measures that can be taken to do so, like creating a capacity for storing rainwater, and increasing infiltration into the ground. These options will assist in decreasing the amount of stormwater runoff in the streets and private property, and help keep streams at their normal levels. In addition to reducing the amount of stormwater runoff, Best Management Practices (BMPs) can also improve the water quality and lower pollution into our waterways. A common misconception is that stormwater is treated through the sanitary sewer system, but it is not. That is why it is crucial to manage stormwater runoff. All storm drains lead to the streams!

Help keep Oak Ridge pollutant-free and beautiful by disposing of chemicals and materials appropriately, and by implementing things such as rain gardens and rain barrels to reduce water runoff into lakes and streams!

If you are interested in reducing the amount of stormwater runoff from your own property, the University of Tennessee’s Institute of Agriculture offers management practices that will help in minimizing this issue. Their stormwater mapping exercise will allow you to see how implementing certain landscape designs, such as rain gardens or rain barrels, have the ability to reduce your personal stormwater runoff.