SinkholeOdds

Sinkhole risk in Western Connecticut Planning Region, CT: 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
9%
At or near the surface
0%
Buried under cover
9%

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 48 of Western Connecticut Planning Region's 532 square miles on soluble rock. With about 637,013 residents (1,197 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 421 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 9% under cover still counts, and how these percentages are measured.

Counties around Western Connecticut Planning Region

The nearest county rated sinkhole country is Union County, PA, about 189 miles west. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Which formation it is

The largest mapped soluble unit here is the Stockbridge Marble (marble), Lower Ordovician and Cambrian in age, covering about 5% of the county. Next is the Basal marble member [of Walloomsac Schist] at 3%.

Against the rest of Connecticut

Western Connecticut Planning Region ranks 9 of 9 in Connecticut for soluble rock at the surface, and sits above 0% of US counties on that measure.