Sinkhole risk in DuPage County, IL: 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: 98%
At or near the surface: 0%
Buried under cover: 98%

What to do about a house in DuPage County

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

That works out to roughly 320 of DuPage County's 328 square miles on soluble rock. With about 937,142 residents (2,858 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 353 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 the 98% under cover still counts, and how these percentages are measured.

Counties around DuPage County

The nearest county rated sinkhole country is Jo Daviess County, IL, about 115 miles west. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Kane County, IL 19 mi west · 0% at surface
Cook County, IL 23 mi east · under 1% at surface
Kendall County, IL 25 mi southwest · 2% at surface
Lake County, IL 27 mi northeast · 0% at surface
Will County, IL 28 mi south · 3% at surface
DeKalb County, IL 35 mi west · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Silurian (dolostone (dolomite)), Silurian in age, covering about 98% of the county.

Against the rest of Illinois

DuPage County ranks 44 of 102 in Illinois for soluble rock at the surface, and sits above 0% of US counties on that measure.