Sinkhole risk in Howard 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: 100%
At or near the surface: 0%
Buried under cover: 100%

What to do about a house in Howard County

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

That works out to roughly 293 of Howard County's 293 square miles on soluble rock. With about 84,082 residents (287 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 330 map points about 0.9 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Howard County

The nearest county rated sinkhole country is Monroe County, IN, about 94 miles south. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Tipton County, IN 12 mi south · 0% at surface
Miami County, IN 20 mi north · under 1% at surface
Cass County, IN 23 mi northwest · 4% at surface
Clinton County, IN 23 mi southwest · 0% at surface
Grant County, IN 24 mi east · 0% at surface
Carroll County, IN 25 mi west · under 1% at surface

Which formation it is

The largest mapped soluble unit here is the Wabash Formation (limestone), Silurian in age, covering about 96% of the county. Next is the Muscatatuck Group at 4%.

Against the rest of Indiana

Howard County ranks 56 of 92 in Indiana for soluble rock at the surface, and sits above 0% of US counties on that measure.