Like earthquakes in LA and traffic in DC, sinkholes are an unpleasant and dangerous fact of life in Florida. A sinkhole is a geologic phenomenon caused by instability under the surface of the ground. When this instability reaches a critical point, a giant hole appears on the surface. These holes are extremely dangerous both to life and property. Larger sinkholes can be 100 feet or more in diameter and swallow entire houses. Sinkholes, as an emergent phenomenon, can appear instantly and grow astonishingly fast. Sinkholes only get worse with time, and in many situations cannot be fixed by man-made methods.
Limestone is the central feature of Florida’s unique geology. Limestone is a type of sedimentary rock formed out of mineral crystals of calcium carbonate. Much of Florida’s limestone comes from the shells of small marine organisms such as coral that have accumulated over millions of years. Florida’s limestone forms what is known as a karst structure – which is the tendency of water to erode certain layers or areas of a rock formation. The limestone in Florida rests on top of layers of solid bedrock. On top of the limestone are sandy topsoil layers that have accumulated more recently in time as the sea levels rose and fell. You might imagine the entire thing as a sandwich, with the limestone being the filling between the bedrock and the topsoil.
Now imagine that, unpredictably, certain parts of the sandwich filling disappear. In reality this is because water has a tendency to react with limestone and dissolve it via a weakly acidic reaction. The limestone layer is riddled with holes, hollow bubbles, pockets and caves. Some of these areas fill with groundwater. Remember this is all going on underneath the “solid” ground.
Sinkholes have been going on for thousands of years. Human activity didn’t cause sinkholes – but it probably made them worse. Building heavy structures exerts pressure on the limestone layers. This pressure can cause one of the structural weaknesses to give way, creating a sinkhole. Realize that the actual hole might start underground, but the layers higher up can collapse in on it, often spectacularly. Less spectacularly, buildings can start to slowly sink into the ground. By some estimates, many government buildings in Beijing are sinking at a rate of about a half-inch per year. Some think this is a manifestation of bad karma resulting from the invasion of and occupation of Tibet.
The water table (groundwater) also plays a large role in sinkholes. Water may actually fill in a pocket in the limestone, providing structural support. If this water is removed, say via a well or pumping, or even during dry summer months via evaporation, it can compromise the structural integrity of that area of the limestone karst. Too much water can be equally bad. Since water can dissolve limestone, something like a lot of rain or excessive runoff can actually cause solid areas of limestone to dissolve. Both situations create sinkholes.
Legal issues around sinkholes arise in the context of property insurance. Florida laws regulate sinkhole insurance coverage in Title 37, Chapter 627, Section 706. In this section, any issuer of property insurance is required to offer “Catastrophic ground cover collapse.” This may be thought of as coverage in case of “Spectacular failure” of the ground. As defined this type of coverage applies only when all four of these things happen:
1) The ground abruptly collapses; and
2) A depression in the ground in visible to the naked eye; and
3) There is structural damage to the building, including the foundation; and
4) The building is condemned by the government and ordered evacuated.
Insurance for the contents of the house, such as personal possessions, applies in such a situation. However this coverage does not apply if there’s damage to the foundation, such as settling or cracking, without ground cover collapse.
Remember that sinkholes are a complex phenomenon: a lot of the damage is more insidious than in the catastrophic collapse scenario. For instance, your neighbor’s home might be swallowed up by a sinkhole, but your own home might only suffer structural damage without being condemned by the government. In that case, your catastrophic ground collapse insurance would be worthless. It is a sad reality that many people think they are covered, but then turn out not to be.
627.706 also states insurers “Shall” offer “Sinkhole loss” coverage for any structure, and allows them to charge an additional amount for this coverage. The insurance company may also inspect the property before issuing the coverage, presumably to determine how much extra to charge or whether to exclude it. That’s right! Under a later paragraph within this section, insurers may exclude sinkhole loss coverage! The only thing they have to do is make sure that fact is noted in your policy in 14-point bold type. In fact, they can choose to “non-renew” your existing sinkhole loss coverage.
Remember this very important fact. “Sinkhole loss” coverage is what you want and what most people think they’re getting with “Catastrophic ground cover collapse” insurance. Sinkhole loss covers structural damage to the building from sinkholes, without any of the other requirements required by “Catastrophic” insurance. And in many, many situations, your house will suffer damage from a sinkhole that conveniently isn’t covered by “Catastrophic” coverage. That is because the insurance industry exerts considerable lobbying efforts to get the laws written the way that they want.
Legal issues tend to take the context of property owner versus insurance company. One of the best things you can possibly do is take preventative action before purchasing your insurance policy. If you are at all concerned about sinkholes, consulting with attorneys who specialize in sinkhole issues might be a good investment. These attorneys can help make sure your insurance policy has the appropriate types and levels of sinkhole coverage. More importantly, they, as people who sue insurance companies all the time over sinkhole issues, can help steer you towards an insurance company that is less likely to low-ball, delay, or fight you if and when your house suffers sinkhole related damage.
Sinkhole issues are complicated because they involve both science and legal matters. If you are unfortunate enough to suffer sinkhole damage, you will probably become all too familiar with geologists, engineers, and state authorities. It is a very, very bad idea to take on insurance companies and “experts” without the assistance of an attorney.
The first typical type of dispute is over repairs. In this situation, there has been a sinkhole-related loss that hasn’t resulted in total destruction of the building. Thus it is up to the insurance company to make you whole, at least up to the policy limits. Part of the repair work is engineering-related. It involves an assessment of what kind of measures will be necessary to prevent further losses. In crude terms, you can think of this as “Shoring up” the sinkhole. Some insurance companies are notorious for having pet “experts” who always recommend minimalistic measures. A lot of these measures fail. Owners who dispute these experts often have the whole process dragged out for years with zero compromise. Unfortunately it may take the threat of a lawsuit (or even an actual lawsuit) to get these companies to play fairly.
The second typical type of dispute is over preventative measures. Similar to the first type of dispute, this occurs when a potential sinkhole problem is found and the insurance company’s representative disagrees with neutral engineers over the extent of required preventative measures. A sinkhole attorney can help you get good quality preventative measures in place so you hopefully will never have to experience the tragedy of a sinkhole loss.