SinkholeOdds

Sinkhole risk in Cortland County, NY: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock
2%
At or near the surface
0%
Buried under cover
2%

What this means before you buy

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 8 of Cortland County's 499 square miles on soluble rock. With about 45,945 residents (92 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 366 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and how these percentages are measured.

Counties around Cortland County

The nearest county rated sinkhole country is Union County, PA, about 124 miles southwest. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Which formation it is

The largest mapped soluble unit here is the Tully Limestone (limestone), Middle Devonian in age, covering about 2% of the county.

The county also lies over the Michigan Basin; Ohio Basin; Appalachian Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of New York

Cortland County ranks 16 of 62 in New York for soluble rock at the surface, and sits above 0% of US counties on that measure.