Sinkhole risk in Vermilion County, IL: No soluble rock mapped

No soluble rock mapped

No soluble bedrock mapped.

On soluble rock: under 1%
At or near the surface: 0%
Buried under cover: under 1%

What this means before you buy

No soluble bedrock is mapped here, so natural sinkholes are unlikely. Collapses from broken pipes or old mines are a separate risk.

That works out to roughly 3 of Vermilion County's 898 square miles on soluble rock. With about 71,106 residents (79 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 381 map points about 1.5 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 Vermilion County

The nearest county rated sinkhole country is Monroe County, IN, about 96 miles southeast. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Warren County, IN 22 mi northeast · 0% at surface
Champaign County, IL 25 mi west · 0% at surface
Fountain County, IN 26 mi east · 0% at surface
Vermillion County, IN 27 mi southeast · 0% at surface
Edgar County, IL 35 mi south · 0% at surface
Benton County, IN 36 mi northeast · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Kinderhookian Series (limestone), Mississippian in age, covering about under 1% of the county.

The county also lies over the Illinois 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 Illinois

Vermilion County ranks 95 of 102 in Illinois for soluble rock at the surface, and sits above 0% of US counties on that measure.