Sinkhole in Yard in Lexington, KY

Why the ground opens up in Lexington

Lexington sits on limestone. Over thousands of years, water dissolves cracks and channels in that rock. Clay soil sits on top like a blanket. When rain soaks in, it carries bits of that soil down into the gaps in the rock.

The Kentucky Geological Survey says this soil can settle slowly for years, then collapse fast and wash out. It says the process speeds up when water runs through loose fill dirt around a house. That fill is often softer than the ground around it, so a house can be the first place water finds a path down.

This is not rare here. State geologists mapped 1,821 sinkholes in Fayette County alone. Lexington even has rules that keep new buildings out of mapped sinkhole areas. Older homes were often built before anyone looked.

How a sinkhole near a house gets fixed

The fix depends on how deep the problem goes and how close it is to the footing. The inspector looks at the hole, the walls inside, and where your roof and yard water go.

Drainage first. Many small yard sinkholes are fed by a downspout or a low spot that sends water to one place. Moving that water away is often the first and cheapest step.

Plugging the throat. For a hole away from the house, crews often dig to the opening in the rock, fill it with large stone, then smaller stone, then clay and soil. This lets water pass slowly without carrying soil down. Simply dumping dirt in tends to fail.

Engineer review. For a hole near the house or one that keeps coming back, you may need a structural or geotechnical engineer. Their report tells the crew what is safe.

Piers under the footing. If soil has washed out under part of the house, steel piers can carry that section down to firm rock. Around Lexington, McAfee soil often has hard limestone just 20 to 40 inches down, which helps.

What to do before the inspection

1. Keep kids, pets and mowers away. Rope it off or set lawn chairs around it.
2. Do not dump trash, branches or loose dirt in it.
3. Turn downspouts and sump pump lines so they drain away from the hole.
4. Take dated photos with a tape measure in the shot.
5. Walk through the house and note any new cracks or sticking doors on that side.
6. Call your insurance agent to ask what your policy covers.

If the hole is near a sewer line, a manhole or the street, call the city too. City crews checked both of the 2019 holes for sewer damage.