I am guessing I am not telling you anything you do not know if you follow sinkhole news but there was a massive sinkhole in Dunedin that opened up last week resulting in at least two homes having to be destroyed. The hole opened after several days of grouting had taken place. The hole opened to as deep as 60 feet reports stated and could take over 300 trucks of dirt to fill in. The home was insured by Citizens and sinkhole activity had been confirmed at the property previously. Luckily, no one was injured but certainly lives were destroyed by the event. This event brings about several talking points though. First, is that yes, sinkholes are in Dunedin and Pinellas County in general. The first response I have heard since last week has been “I didn't know there were sinkholes in Dunedin”. We have stressed this on countless occasions through this site that sinkholes are everywhere in Florida, and even outside of Florida. In fact, a large majority of the most catastrophic sinkholes in Florida history were not in the sinkhole heaven of Pasco and Hernando counties. Remember the largest sinkhole known in Florida was in Winter Haven and now this one in Dunedin.
The next salient point to take from this is that most collapses occur while the sinkhole is being repaired. Again, this surprises people not in the industry. When you pump grout in the ground it disturbs the soils around these large underground voids. These voids can be in a volatile state naturally and then when you disturb them with high pressure concrete flowing suddenly, the potential for collapse can be great. Many engineers when they see a such a risk will recommend underpinning a home first. They call these contingency underpins. They are not meant to necessarily re-level the home but can be used to ensure that if and when the ground collapses the house is supported. The home in Dunedin may have even be salvageable if this had taken place. At the very least, the family would have been able to save some more of their belongings. With this particular home, the homeowners own expert had recommended some different repairs than what Citizens did. These repairs may have been safer and may have even saved the home but Citizens refused and forced the homeowners to go forward with what they recommended. Guess they got what they wanted.