Sinkholes Suck

Earthquakes, tornadoes  floods, hurricanes, and landslides cost homeowners millions of dollars in damage each year; us Floridians have always focused our attention to hurricanes, but with growing number of sinkholes being reported the focus is shifting.  

Sinkholes are naturally occurring holes in the surface of the earth.   They can form gradually over time as the underground water dissolves layers limestone bringing the soil with it or suddenly.

In addition to Florida being made up of a young very weak, porous, Limestone that is easily weathered by the extreme conditions endured throughout storm season. Pumping from aquifers increases the chances of formation. As well as droughts that cause low ground water levels, that reduces the support of a cavity or the combination of low ground water then heavy rains or floods. 

Sinkholes can also be caused by growing population and development. The changes in drainage patterns, construction, and heavy traffic all have impacts. Building in areas like “sinkhole alley” with limestone depth less than 200 feet are examples of the modern sinkholes that we see on the news today. 

Whether natural or man induced, there are many types of sinkholes. The most common three are:

• ·        “Solution” sinkholes: when the limestone is exposed at the surface or covered by a thin  layer of soil leaving the limestone subject to physical and chemical process that break downs the rock forming a cavity or void. These type develop slowly, but are continuous.
• ·        “Cover-subsidence” sinkholes: when the sand layer is around 50-100 feet with very little clay around it. As the limestone dissolves, sand falls in filling the void. These types are known to not get very large in diameter or depth due to the sand fill.
• ·        “Cover-collapse” sinkholes: when the solution cavity develops in the limestone that the overlaying cover material can no longer support the weight. Greater chance of collapse when the limestone aquifer is below level.

Certain Signs that a sinkhole is about to open up.

-Slumping trees or fence posts

-Formation of small ponds where they had not been before

-Wilting of small area of vegetation in circular pattern

-cracks in building foundation

If you notice signs

-provide safety for your family. Evacuate if necessary

-secure or move valuable possession safely

-Notify your insurance company

-Mark the sinkhole or property with tape or rope to signify danger. 

 * You could be held liable if someone is injured.

For those who are buying a home...

• Be sure that the house is insurable. Is sinkhole coverage included in your policy?
• Hire a home inspector that can find signs of potential activity (especially in central-western Florida)