Sinkhole risk in Lake 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%

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 436 of Lake County's 444 square miles on soluble rock. With about 718,604 residents (1,620 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 357 map points about 1.1 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 Lake County

The nearest county rated sinkhole country is Muskegon County, MI, about 111 miles northeast. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Cook County, IL 22 mi south · under 1% at surface
DuPage County, IL 27 mi southwest · 0% at surface
Kenosha County, WI 28 mi north · 0% at surface
McHenry County, IL 34 mi west · 0% at surface
Kane County, IL 36 mi southwest · 0% at surface
Racine County, WI 41 mi north · 0% at surface

What Lake County is built on

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

Lake County ranks 64 of 102 in Illinois for soluble rock at the surface, and sits above 0% of US counties on that measure.