SinkholeOdds

Sinkhole risk in Orange 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
15%
At or near the surface
0%
Buried under cover
15%

What to do about a house in Orange County

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

That works out to roughly 122 of Orange County's 812 square miles on soluble rock. With about 411,767 residents (507 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 608 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Read next: why the 15% under cover still counts, and how these percentages are measured.

Counties around Orange County

The nearest county rated sinkhole country is Union County, PA, about 146 miles west. 3 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 Wappinger Group (limestone), Cambrian - Lower Ordovician in age, covering about 9% of the county. Next is the Rusty and gray biotite-quartz-feldspar gneiss at 2%.

Against the rest of New York

Orange County ranks 38 of 62 in New York for soluble rock at the surface, and sits above 0% of US counties on that measure.