Does Pasco County Have A Sinkhole Problem?

8/22/07

According to the Southwest Florida Water Management District (SFWMD), Florida "is the land of sunshine, beautiful beaches … and sinkholes." According to SFWMD, the "West Central Florida region has the highest possibility of sinkhole development. Sinkholes develop more frequently north of Tampa Bay where the limestone base is closest to the land surface and the supporting sand and clay layers are thin."

Pasco County is located in West Central Florida. But does the county have a sinkhole problem?

New research by the Florida Association of Sinkhole Stabilization Specialists, in a survey of nine geotechnical firms working in the county to diagnose sinkhole development, finds that in 2006 the firms saw a total of 855 confirmed sinkholes in Pasco County.

If you take this number and compare it to the number of residential home fires in Pasco County in 2006, you'll find that a home in Pasco County is three times more likely to be damaged by a sinkhole than by a fire.

The reason for the high number of sinkholes is due to Pasco's geology. Many areas of Pasco County have a relatively thin cover of sand and clay over limestone bedrock. These soils overlying the limestone bedrock are highly susceptible to erosion and subsidence as percolating rainwater passes through them and into the underlying aquifer. This natural process aids in the recharge of the Floridian aquifer system and is the primary mechanism for sinkhole formation in the county.

The incidence of sinkholes is particularly important to Pasco County homeowners as their insurance policies come up for renewal. Recently enacted legislation will allow Citizens Property Casualty Insurance Company and other insurance carriers to automatically drop sinkhole coverage from Pasco and Hernando County home insurance policies upon renewal beginning September 1. These homeowners will be allowed to purchase an optional sinkhole rider to provide some coverage.

The most common type of sinkhole is the slow moving subsidence sinkhole, which if left untreated, will eventually render a home worthless. The changes in insurance will cover only "catastrophic ground cover collapse" sinkholes, which are extremely rare. Geologists estimate that this type of sinkhole represents less than one-tenth of one percent of sinkholes confirmed in West Central Florida.

It is important that Pasco County homeowners know about their insurance coverage and their risks. The Florida Department of Financial Services reports that "sinkholes are an unpredictable part of the Florida landscape, especially in West Central Florida and the greater Tampa Bay area."

Homeowners can find maps and other information on sinkholes by visiting www.myflorida.com and type in "sinkholes" in the search area.

According to SWFMD, sinkholes usually offer some warning signs before occurring:

• Previously buried parts of fence posts, foundations and trees become exposed because of sinking ground.
• Slumping, sagging or slanting fence posts, trees of other objects.
• Doors and windows that fail to close properly.
• Cracks in walls, floors pavement and ground surface.
• Small ponds of rainfall forming where water has not collected before.
• Wilting of small, circular areas of vegetation because the moisture that normally supports vegetation in the area is draining into the developing sinkhole.
• Muddy water in nearby wells during early stages of sinkhole development.

Repairs of sinkholes are the responsibility of the property owner. If your home shows these warning signs, contact your insurance company.

The Florida Association of Sinkhole Stabilization Specialists brings you this message.

Contact: Cindy Sharpe, (813) 244-2883 cell, (813) 986-0877 office, csharpe@digitallightbridge.com

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