Sinkhole risk in Lake County, IN: 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: 72%
At or near the surface: 0%
Buried under cover: 72%

What to do about a house in Lake County

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

That works out to roughly 359 of Lake County's 499 square miles on soluble rock. With about 502,955 residents (1,008 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 342 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why the 72% under cover still counts, and how these percentages are measured.

Counties around Lake County

The nearest county rated sinkhole country is Barry County, MI, about 131 miles northeast. 3 of the 6 closest counties land in the same band; the ground changes quickly around here.

Porter County, IN 16 mi east · 0% at surface
Will County, IL 31 mi west · 3% at surface
Cook County, IL 32 mi northwest · under 1% at surface
LaPorte County, IN 33 mi east · 0% at surface
Jasper County, IN 34 mi southeast · 0% at surface
Kankakee County, IL 34 mi southwest · 6% at surface

What Lake County is built on

The largest mapped soluble unit here is the Wabash Formation (limestone), Silurian in age, covering about 39% of the county. Next is the Muscatatuck Group at 33%.

Against the rest of Indiana

Lake County ranks 63 of 92 in Indiana for soluble rock at the surface, and sits above 0% of US counties on that measure.