Sinkhole risk in Van Buren County, IA: 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: 41%
At or near the surface: 0%
Buried under cover: 41%

What this means before you buy

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

That works out to roughly 199 of Van Buren County's 485 square miles on soluble rock. With about 7,217 residents (15 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 394 map points about 1.1 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and why the 41% under cover still counts.

Counties around Van Buren County

The nearest county rated sinkhole country is Calhoun County, IL, about 129 miles southeast. 6 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Jefferson County, IA 17 mi north · 0% at surface
Scotland County, MO 23 mi southwest · 0% at surface
Davis County, IA 24 mi west · 0% at surface
Lee County, IA 26 mi east · 2% at surface
Henry County, IA 27 mi northeast · 0% at surface
Clark County, MO 27 mi southeast · 0% at surface

What Van Buren County is built on

The largest mapped soluble unit here is the Meramec Series (limestone), Late Mississippian in age, covering about 31% of the county. Next is the Osage Series at 10%.

The county also lies over the Forest City 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 Iowa

Van Buren County ranks 90 of 99 in Iowa for soluble rock at the surface, and sits above 0% of US counties on that measure.