North Sulphur project had unintended results
If you look at a map of the North Sulphur River as it passes through Fannin County and becomes the border between Lamar and Delta County, you’ll see that it’s suspiciously straight. The reason for that is that the channel of the North Sulphur was dug, not by natural forces, but by engineers. The project began in the late 1920s as a response to the flooding and swampy conditions around the river. The result: Erosion.
Haslett : From KETR News, this is Tomorrow’s Water Today, a weekly look at issues affecting the present and future water resources of Northeast Texas. I’m Mark Haslett. Last week, we began looking at the proposal to put a lake in southern Fannin County, just north of Ladonia. Lake Ralph Hall would be a source of municipal water for the cities of the region, including the Dallas-Fort Worth area . However, there’s also an environmental argument for the proposed lake. That argument has to do with the state of the North Sulphur River. If you look at a map of the North Sulphur River as it passes through Fannin County and becomes the border between Lamar and Delta County, you’ll see that it’s fairly straight. It’s almost suspiciously straight, compared to the winding paths followed by the other creeks and rivers of the region. The reason for that is that the channel of the North Sulphur was dug, not by natural forces, but by engineers. The project began in the late 1920s as a response to the flooding and swampy conditions around the river.
Franklin: Everybody wanted the swamp drained. It would create new farm land. And of course the farm lands were supposed to be rich because it sat there and collected all of the sediment and organics for eons.
Haslett: That’s Doug Franklin of Ladonia, who took me on a guided tour of where the North Sulphur runs underneath State Highway 34.
Franklin: They went to the north of this meandering North Sulphur creek and dredged a channel that was 16 feet wide – and that’s not exact science. Sometimes it may have been twenty feet wide- and ten feet deep. I’m going to show that to you now.
Almost immediately it began to erode because they straightened a meandering creek. When you straighten a creek, you speed up the flow tremendously.
Haslett: The total length of that stretch of the North Sulphur was reduced by half. Of course, it still had to carry the same amount of water. So, when the rains came, the once-lazy creek became a swiftly-flowing little river. That didn’t alarm people at first. The project looked like a success. The bottom land muds had become arable fields and the roads of the area became passable by ordinary vehicles. Early returns on the new North Sulphur were optimistic.
Franklin: In August of 1929, a Dallas Morning News report reported that the bridge over North Sulphur Creek had been installed since the dredging, and this one should be one that should never have to be replaced. It was a hundred feet wide. So in one year, it had eroded that much.
Today, its three hundred feet wide, we’re going to take a look at it. You can put two Panama Canals side by side in this channel that’s been created from erosion, and it’s continuing to grow. It’s growing at a rate of 1 foot per year on each side.
Haslett: It didn’t take long for the rapid pace of erosion to become evident.
Franklin: The calculations have been made on the number of tons of topsoil that’s been lost in the North Sulphur River watershed since this dredging: 30 million tons of topsoil. Now that’s enough topsoil to create a path from Fannin County to the moon.
Haslett: We’ll go for a walk down in the riverbed and learn about the effects of the ongoing erosion next week on Tomorrow’s Water Today. For KETR News, I’m Mark Haslett.