SinkholeOdds

Sinkhole risk in Bronx 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
6%
At or near the surface
0%
Buried under cover
6%

What to do about a house in Bronx County

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

That works out to roughly 2 of Bronx County's 42 square miles on soluble rock. With about 1,384,724 residents (32,813 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 241 map points about 0.4 miles apart, so a pocket smaller than that can be missed or overstated.

Read next: why the 6% under cover still counts, and how these percentages are measured.

Counties around Bronx County

The nearest county rated sinkhole country is Union County, PA, about 167 miles west. 1 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 Inwood Marble (marble), Early Cambrian - Lower Ordovician in age, covering about 6% of the county.

Against the rest of New York

Bronx County ranks 9 of 62 in New York for soluble rock at the surface, and sits above 0% of US counties on that measure.