Why sinkholes? Why now?
East Tennesseans are no stranger to sinkholes, but this spring it seems that every time we turn around, we are out to investigate a new one!
We’ve got a lot of new people in town, so let’s start with the basics. What is a sinkhole? East Tennessee sinkholes appear when rain erodes rock over several years, and then one day, the top layers of dirt give way, revealing a cavern in varying sizes. We cannot predict when or where they will happen, and we do not know where they go.
Knox County has been around since 1792, so why are we seeing so many appear now? Blame it on the rain. We have seen big storms and irregular flooding in February for the last few years. Flooding saturates deeper into the ground which can cause deeper rock erosion. The next rain that comes along then washes it all away.
What does Knox County do about it? Well, it depends on where it is. If the sinkhole is on private property and not threatening any county assets, then we are happy to come out, assess the situation and give some advice, but ultimately it is the homeowner’s decision and responsibility to fix it. If the sinkhole is on public property or threatening one of our assets, we will come in and fix it. How we fix it is based on the size and scope of the sinkhole. Sometimes it just needs some #57 stone and crusher run, and other times we have to fill it with concrete. We typically top it off with a layer of dirt, seed and straw so grass will grow back over it.
Rylie McClurg is the communications and outreach coordinator for Knox County Engineering & Public Works.