Sinkholes can be small depressions or huge craters that swallow roadways and buildings.
Florida has more sinkholes than any other state in the nation, according to a study prepared by the Florida House of Representatives.The limestone and dolomite layers that form most of the state are just under the topsoil. When rain and water flow through the topsoil and into the limestone or karst layer, collapses called sinkholes naturally occur. Human activity can exacerbate the problem through urbanization of the natural environment and the loss of topsoil and ground covers. The U.S. Geological Survey says most sinkholes occur in Florida, Texas, Alabama, Missouri, Kentucky, Tennessee and Pennsylvania. Does this Spark an idea?
Legislative Warning Signs
The Florida House of Representatives prepared a study for amendments to an insurance bill that outlines some signs of impending sinkholes. According to the study, sinkholes may occur in the presence of tilting and falling fence posts and trees; slanting foundations; sudden new small ponds or unexplained sudden drainage of a pond; overnight appearance of craters and holes; areas of wilted vegetation; discolored well water; and structural cracks in buildings.
Surface Activity and Acid Rain
A main reason for collapse of the karst formation is the acidity of the water that eats through limestone and other soft stone. Rainfall is slightly acidic, and it picks up more acid when it filters through vegetation. But a healthy cover of topsoil and other geologic materials can filter the rain and remove some acidity so it is less corrosive to limestone. When an unstable area experiences intensive building, vibration, pumping of water and alteration of the natural landscape, the threat of sinkholes increases.
Cracks
Houses settle, and not all signs of settling are preludes to sinkholes. But new or widening cracks may signal a problem. Evaluators who assist homeowners in preparing sinkhole insurance claims list a number of cracks to monitor: separation between walls and ceiling or floors and walls; cracks in interior and garage walls; cracks around corners of door and window frames; cracked floor tiles or popped bathroom tiles; driveway cracks; exterior wall cracks; any building cracks that form a stairstep pattern.
Landscape Irregularities
Some signs of sinkhole activity might include a leaking or mysteriously draining inground pool; dips and depressions in the yard; holes in the yard; dead patches of grass, garden plants or shrubs; increasing yard slope; cracks or shifts in fences or retaining walls; neighborhood sinkholes. Residential sinkhole public adjusters caution that drainage ponds, lakes and canals in the vicinity may be signs that the area has experienced sinkholes in the past and is still vulnerable.
Tags: Florida House, Florida House Representatives, House Representatives, sinkholes occur, that form, walls cracks
