Though they are a very common, naturally occurring geologic phenomenon, sinkholes are classified as a geologic hazard that can cause extensive damage to structures, roads, parking lots, and yards that can result in costly repairs. They can even threaten water supplies by draining unfiltered water from streams, lakes and wetlands directly into our underground water supply.
They are common where the rock below the land surface is carbonate rock, limestone, salt beds or simply rocks that naturally dissolve when groundwater circulates through them. As the rocks begin to dissolve, 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. 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 large and can occur under a building or road. In Toledo and the surrounding areas, much of our subterranean earth is limestone and dolomite.
Sinkholes can appear overnight. However, the majority of them evolve over time, developing long before they are noticed on the surface. Anywhere there is a lot of underground rock or clay, is a perfect place for a sinkhole to form. A common misunderstanding is that a sinkhole is actually a hole in a rock. The reality is, the sinkhole is what we see on the ground surface because of the hole in the rock below.
In Toledo, our streets have encountered many sinkholes. Part of that is due to the deterioration of the sewer system, the fact that many streets were, and still are, brick, and that are primarily built on a swamp, along with the limestone as previously mentioned.
While not all sinkholes are as dramatic as the road simply opening up, it’s important to be aware of the warning signs of one forming on your property.
If you are noticing a combination of these signs, we suggest you take immediate action:
- Fresh exposures on fence posts, foundations or trees that result when the ground sinks around them
- Slumping, sagging or slanting fence posts, trees or other objects
- Doors and windows that fail to close properly or exhibit changed behavior such as doors remaining open where they had previously closed of their own accord
- Small ponds of rainfall forming where water has not collected before
- Wilting of small, circular areas of vegetation. This happens because the moisture that normally supports vegetation in the area is draining into the sinkhole that is developing below the surface
- Cloudy water is pumped from nearby wells where the water was previously clear
- Cracks in walls, floors, pavement and the ground surface. This is most noticeable in a concrete block structure and is different from a few hairline cracks normally seen between blocks
Be extremely careful before examining a sinkhole. As a matter of fact, we recommend against that. If you feel it’s an emergency, by all means call either the water company or gas company.
While many sinkholes aren’t large, some will require excavation to replace or repair water, sewer or gas lines. The professional staff at E & K Contractors is here to help. We can come out and give you an estimate, and the peace of mind knowing that our portion of the work will be done professionally, and expediently.