Sinkholes are most likely to open up when there has been a long drought followed by normal rainfall. And a mild drought followed by the excessive rainfall from a hurricane can also increase the incidence of sinkholes. "A large rain event can weigh the soil down and can cause sinkholes to form,” according to the Florida Department of Environmental Protection. "When the water level in the underlying limestone aquifer is depressed (due to drought or consumptive uses), the void spaces that once held water now are filled with air. Water provides some buoyancy and can keep the overlying geologic material stable. When the void contains air, it is less competent, and when a large rain event weighs down the overburden, it can collapse into the underlying air-filled void."

    The last extended period of drought in Florida occurred from 2011 through the first half of 2012, which was followed by higher-than-normal sinkhole activity. Florida also had a two-year period during 2004 and 2005 when eight rain-laden hurricanes hit the state.

    But structural damage that resembles sinkhole activity under a home can also occur due to clay soil during the same drought-followed-by-rainfall periods. To read more about clay soil issues, go to our article How can I tell whether my house foundation problems are caused by a sinkhole or expansive clay soil?

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Here’s links to a collection of our blog posts about “SINKHOLES":

• Where are sinkholes most likely to occur in Florida?

• How can homebuyers protect themselves against buying a house over a sinkhole? 

• What is a chimney sinkhole?  

• What are the warning signs of a sinkhole? 

• What causes sinkholes? 

• What is my chance of buying a Florida home over a sinkhole? 

• How does a repaired sink hole under a house affect its market value?  

• Are there sinkholes in The Villages, Florida?

• Are sinkholes happening more often? 

• What are the basic facts about sinkholes? 

• Does homeowners insurance in Florida include coverage for sinkhole damage? 

• Should I be concerned about an old sinkhole on a property?

• Should I be concerned about my house if a sinkhole opens in my neighbor's yard? 

• What are the Florida law regarding sinkhole insurance?

• Can a home inspector determine if there are any sinkholes on a property?

• Is it safe to buy a house with sinkhole foundation repair? 

• What can I do if the insurance company denies my claim for a sinkhole loss in Florida?

    Visit our SINKHOLES page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles. 

- Photo at top of page courtesy Southwest Florida Water Management District