As we’ve started talking about our Florida sinkholes a couple of people have asked us what causes sinkholes. Specifically, people often want to know if they are a natural phenomenon, or what might be done to stop them.
Sinkholes are a natural geologic phenomenon. They happen all over the world and they’ve been happening for thousands of years.
However, certain human activities do make sinkholes occur more often when those activities have an effect on underground geology.
As water flows underground it dissolves underground rock. This can happen very slowly in areas where the underground rock is very hardy.
In Florida, however, our rock is mostly limestone, which is very porous and which erodes easily. We also have dolomite, which is another soft rock.
When this happens, an underground hole or cavern eventually forms. The sediment above ground eventually falls into the hole, creating a sinkhole.
Extreme rainy weather can have a serious effect on this underground landscape. Our Florida floods and rains don’t do anything to help this situation.
This is especially true because acidic water is particularly good at eroding the underground stone. Most rain is at least a little bit acidic, and it takes on more acidity by passing through decaying vegetation and debris on the ground.
However, the danger from extreme weather does pale in comparison to the man-made activities which can exacerbate sinkhole problems. Specifically:
- Pumping a great deal of water out of the ground
- Drilling new wells
- Creating artificial ponds
- Removing too much ground water for other purposes.
There are also some other problems which can exacerbate sinkholes, things that we don’t do on purpose but which happen anyway. Collapsed and broken sewer lines can also be causes of sinkholes, for example.
This can be challenging as all of these man-made activities represent things that we need to do in order to make sure everyone has water to use in their homes and businesses. This has caused a lot of debate about the ways that our state water resources are used and managed.
Our groundwater has been steadily declining for some time, for example. From the USGS:
West-central Florida – Groundwater development in the Tampa-St. Petersburg area has led to saltwater intrusion and subsidence in the form of sinkhole development and concern about surface-water depletion from lakes in the area. In order to reduce its dependence on groundwater, Tampa has constructed a desalination plant to treat seawater for municipal supply.
You can make your own decisions about the way you use water if you are concerned about sinkholes and other water use issues in our state. For example, you can decide to use a rainwater catchment system, which will help conserve our state’s water resources.
Rain Control Gutters is a seamless gutter company serving Wesley Chapel, Land O’ Lakes, New Port Richey and the rest of the Tampa Bay area right in the heart of Florida’s “sinkhole alley.”