Conservation Corner: Water runs downhill, carrying whatever it can along the way
Published 10:00 pm Wednesday, July 26, 2017
I want to spend a few minutes expounding upon the simple premise that water flows downhill, and takes whatever it can with it as is goes. Of course that sounds like something that a 3-year-old can understand, but it seems to be one that is difficult for us grown-ups to take seriously when it comes to land management around streams.
Let’s start with a few definitions:
The drainage area of a stream encompasses all the land from which surface runoff flows into that stream. Do you know what stream drainage you live in? Stream order: A stream with no tributaries is a first order stream. A stream with only first-order tributaries is a second order stream. A stream that has any second-order tributaries and none higher is a third-order stream, and so on.
The Mississippi River is a tenth order stream, one of the highest order streams on earth. As more and more tributaries join together, a larger stream network is formed and the master stream, the highest order stream in the system, has a discharge that is the sum of all the tributary discharges.
There’s a reason why I highlighted the last phrase. What we do in Saluda and Polk County, braided by hundreds of first order streams, affects the health of all the streams and rivers from here to the Atlantic Ocean. Many years of water testing on the Pacolet and the Green have taught us that sedimentation is the number one pollutant of our waterways; years of river studies have proven that streambank erosion on first and second order streams is the biggest contributor to sedimentation buildup in our rivers and lakes and bays.
So, it is pure ignorance for a landowner to think that cutting deep rooted vegetation next to the streambank has no negative impact on others. Out of sight; out of mind? I guess that’s the explanation.
This picture of the lake at Camp Glen Arden in Tuxedo was taken after a normal summer rain. It may not be apparent in this black and white picture, but the lake water is the color of chocolate milk rather than the crystal clear, sparkling water upstream.
The tiny Glen Arden lake is fed by a second order stream, less than mile from its water source. When the dam is opened, all the sediment goes down the Green River, ending up at Lake Adger. If and whenever that dam gets opens, the water and sediment keeps on going downhill, picking up whatever it can to carry out to the ocean.
What we do impacts many, many creatures downstream, whether we can see those creatures or not.
Cherish the vegetation on your streambank. It preserves life.