Should I be concerned about an old sinkhole on a property?
Tuesday, July 30, 2019
We often inspect rural homes with a deep, but rounded depression that appears to be an older sinkhole on the property—so old that tall trees are growing out of it. Here’s what the Florida Department of Environmental Protection (FDEP) recommends:
"If you have a sinkhole on a large property, and it is not actively developing or impacting some activity on the property, it can be left alone. If there is a danger of people or animals falling into the depression, it can be filled with clayey sand or it can be fenced off. Do not fill it with organic material or something that could potentially decompose or release potential toxins into the underlying groundwater.
Many people have sinkholes on their property that are just part of the natural landscape. If one suddenly appears, we suggest filling it with clayey sand as the clayey material will retard water movement. Water flowing into a sinkhole can cause it to expand and become more active. Never throw anything into a sinkhole that could possibly contaminate groundwater."
There are no restrictions on sinkholes that are inactive and overgrown with vegetation, but that does not mean everything is definitely alright. “At any given time, a sinkhole can become active,” according to Betty Levin, senior environmental specialist with Alachua County, Florida.
A buffer distance, which varies by county, is required between new home construction and any significant geological feature such as an active sinkhole. An active sinkhole is defined as one with an opening, exposed limestone or recent soil movement.
The largest old sinkhole we know of is a tourist attraction, the Devil’s Millhopper Geological State Park, in Gainesville, Florida. It’s 212 steps down to get to the bottom, along a boardwalk shown at the top of the page.
• • • • • • • • • • • • • • • • • • • • • • • • • •
Here’s links to a collection of our other blog posts about SINKHOLES:
How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manfuactued and modular homes
for Links to Collections
of Blog Posts