Sinkhole risk in Orleans County, VT: 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: 34%
At or near the surface: under 1%
Buried under cover: 34%

The next step for one property

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

That works out to roughly 236 of Orleans County's 695 square miles on soluble rock, 3 of them with the rock at or near the surface. With about 27,726 residents (40 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 253 map points about 1.7 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 34% under cover still counts, and how these percentages are measured.

Counties around Orleans County

The nearest county rated sinkhole country is Union County, PA, about 361 miles southwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Lamoille County, VT 24 mi southwest · 0% at surface
Caledonia County, VT 26 mi south · 0% at surface
Essex County, VT 26 mi east · 0% at surface
Franklin County, VT 32 mi west · under 1% at surface
Washington County, VT 42 mi southwest · 0% at surface
Chittenden County, VT 47 mi southwest · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Waits River Formation (limestone), Devonian in age, covering about 27% of the county. Next is the Waits River Formation, Ayers Cliff Member at 6%.

Against the rest of Vermont

Orleans County ranks 4 of 14 in Vermont for soluble rock at the surface, and sits above 52% of US counties on that measure.