David Smith got a surprise when he walked out of his business, Glenn’s Warehouse Carpets on College Street, on Monday. A small sinkhole had formed almost in the center of the parking lot.
“There was a depression in the asphalt and, later in the day, the asphalt fell through,” he told the Sun. “I could see a hole, so I took a long pole and the first level that it stopped at was about 10 feet from the surface.
“When our helper got a flashlight, we could see off to one side there was a ledge that dropped another 10 feet or so,” he said. “We could also see a line of bricks down in there.”
Smith said a member of the city of Waxahachie’s engineering office has inspected the hole, which revealed a look into an old tunnel system the city has been mapping.
“The city engineer that came out [Tuesday] morning has been actually traveling though some of these tunnels,” Smith said. “These tunnels are under here and [the city engineer] pointed back towards downtown. He said they have been going underneath the streets mapping and measuring and it was good for them today to see this access and have a view from this side.
“[The city engineer] said there was a creek that was going through here and the property owners individually wanted not to interfere with the creek so they built this little arch there,” Smith said.
Smith said the hole is about 8 inches in diameter and is blocked off by a large sign that reads “keep away” to warn people not to park in the parking lot but to park on the street.
“I am going to wait further until I hear from the engineer and see what my options are,” Smith said. “It is not safe to park right there (but) I don’t think it’s in danger of damaging my building.”
According to the U.S. Geological Survey’s website, sinkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds or rocks that can naturally be dissolved by groundwater circulating through them. As the rock dissolves, spaces and caverns develop underground.
“Sinkholes are dramatic because the land usually stays intact for a while until the underground spaces just get too big,” the USGS site states. “If there is not enough support for the land above the spaces, then a sudden collapse of the land surface can occur. These collapses can be small or they can be huge and can occur where a house or road is on top.”
According to the USGS, a sinkhole is an area of ground that has no natural external surface drainage. When it rains, the water stays inside the sinkhole and typically drains into the subsurface. Sinkholes can vary from a few feet to hundreds of acres and from less than 1 foot to more than 100 feet deep.
The Sun will be meeting with the city engineer for further information about the old tunnel system and whether it has any relationship to the sinkhole.