What Does Stormwater Runoff Look Like?


stormwater-runoff--steve-white

On a recent run on a mountain trail near North Carolina’s Blue Ridge Parkway, my wife and I came upon a pretty dramatic sight. Just about 30 yards downhill from the Parkway, there was a large drain pipe with the outflow frozen solid. Where you might normally assume that this frozen waterfall would be crystalline white, it was far from it. Instead, it was more of a “burnt orange”, unlike any natural color around it.

While I did not take a sample to find out what was causing the orange color (perhaps a combination of iron rust and road deposits including oil and gas from passing cars), what was most striking was that even in this remote area of a protected landscape, there was enough pollution and trash on the road to dominate what you would expect to be a natural setting. And while we normally would not be able to visibly see what was being swept into the pretty little stream below, there it was literally frozen in time.

The stream ultimately flows into the New River, then the Ohio, then the Mississippi. Thinking of how many hundreds of streams like this bring this polluted runoff to the many towns and cities along that route makes it even more important to address it wherever possible.

Peter Raabe, our NC Director, described polluted storm-water as one of the biggest problems facing our streams and said that in most places there is no treatment to purify the water prior to it getting to our streams and ultimately our water supply. That was certainly the case here, and now my wife and I have a stark image to remember that by.

If you would like to learn more about storm-water runoff pollution and what you can do about it, please click here.

2 Responses to “What Does Stormwater Runoff Look Like?”

David Friedman

Natural undisturbed soils do NOT have any runoff.
Why? Because they have 25% pore space, rapidly infiltrating rainfall at the point of impact with the soil surface. The trees and other vegetation intercept at least 10% of the rainfall. There are numerous studies that have been published proving these facts. George P. Marsh wrote “Man and Nature” over 100 years ago proving that the soils in Vermont do not freeze in the winter, Why? Because of the larger soil pores drain rapidly and the soils do not freeze beneath the snow, they function all year round. However, when heavy equipment used in constructing housing or simply clearing and grading soils they crush the soil pores permanently resulting in severe soil compaction. Reports by US Forest Service, USDA-NRCS, US Parks Service, Ocean County Soil Conservation District, Ocean County, NJ ” Impact of Land Disturbance on Soil Bulk Densities and Infiltration Rates….” I measured infiltration rates in undisturbed soils having rates exceeding 15 inches per hour. These same soils following clearing and grading had infiltration rates of .03 inches per hour.
These disturbed soils had soil bulk densities approaching the density of concrete. Is there any wonder why we are seeing excessive runoff from disturbed lands? This is not a local issue it is ubiquitous.
Healthy functional soils are at the root of everything.
David Friedman
Excessive runoff itself is a pollutant! Soil compaction

Todd

It is sad that the NC Legislature stepped in to delay rules protecting the Haw River/Jordan Lake system. Instead they launched a pilot study of aerators in an arm of Jordan. So not one gram of polluted runoff is prevented from entering Jordan while a private company is funded to provide these aerators!