About That Mar-a-Lago Sinkhole...

The growing problem of aging underground infrastructure is no laughing matter.
05/25/2017 12:04 pm ET Updated May 25, 2017

When news broke last week that a sinkhole formed at Donald Trump’s resort and weekend White House known as Mar-a-Lago, the press and social media had a field day. The headline in the Washington Post declared, “Sinkhole forms in front of Mar-a-Lago; metaphors pour in.” Twitter went full snark. Even Cher got into the laughfest.

Many who know me as a Florida sinkhole expert forwarded several articles about the collapse. By all reports, the sinkhole was a small 4-foot square collapse feature.

But was it really a sinkhole?

When I heard the news, I was highly skeptical.

A sinkhole is a collapse of a void space that forms from the solution of soluble rock—usually limestone.

In Florida, most of the limestone that contains void spaces large enough to cause a sinkhole the size of the one at Mar-a-Lago is found near the surface in central Florida near Tampa and Orlando. Some large sinkholes in this area have caused tremendous property damage and loss of life.

But Mar-a-Lago? According to state geologic maps of Palm Beach County, the site is underlain by the Anastasia formation, a geologic unit consisting of a mix of late Pleistocene sands and a type of limestone called coquina—a weakly cemented rock made of shells. While sinkholes can form in the formation, they are not at all a common occurrence.

So if it wasn’t a sinkhole, what was it?

The Palm Beach Daily News is reporting that it was a collapsed stormwater pipe and not a sinkhole—at least not a geologic sinkhole.

In recent years, we have taken to using the term sinkhole for any collapse feature that suddenly forms on the surface of the earth. Geologists shudder at the expansion of the definition away from the purely geologic. But to the general public, there is little difference. Whether sinkholes form from collapsed pipes or from collapsed limestone, the resultant holes cause disruptions in our communities and in our daily lives.

Recently, the Associated Press published an article by Roger Schneider about the growing national problem of sinkholes that form from collapsing aging underground infrastructure. Each year, local governments spend millions of dollars on repairs and countless people are inconvenienced when holes open up on roadways, sidewalks, parking lots, and even under buildings as a result of collapses similar to the one at Mar-a-Lago.

While it is easy to have a good chuckle at the President’s expense about the sinkhole at Mar-a-Lago, the growing problem of aging underground infrastructure is no laughing matter.

A natural sinkhole in central Florida.
Robert Brinkmann
A natural sinkhole in central Florida.
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