SinkholeOdds

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

No soluble rock mapped

No soluble bedrock mapped.

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

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 2 of Saline County's 380 square miles on soluble rock, 2 of them with the rock at or near the surface. With about 22,826 residents (60 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 399 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and how these percentages are measured.

Counties around Saline County

The nearest county rated sinkhole country is Hardin County, IL, about 22 miles southeast, close enough that the same rock may run under the county line. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

The rock underneath

The largest mapped soluble unit here is the Lower Chesterian (Glen Dean - Renault) 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

Saline County ranks 26 of 102 in Illinois for soluble rock at the surface, and sits above 53% of US counties on that measure.