Sinkhole risk in Blue Earth County, MN: 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: 49%
At or near the surface: 0%
Buried under cover: 49%

What to do about a house in Blue Earth County

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

That works out to roughly 363 of Blue Earth County's 748 square miles on soluble rock. With about 70,700 residents (95 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 357 map points about 1.4 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Blue Earth County

The nearest county rated sinkhole country is Clayton County, IA, about 160 miles southeast. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Waseca County, MN 24 mi east · 0% at surface
Nicollet County, MN 24 mi north · 0% at surface
Faribault County, MN 25 mi south · 0% at surface
Watonwan County, MN 28 mi west · 0% at surface
Le Sueur County, MN 29 mi northeast · 0% at surface
Martin County, MN 34 mi southwest · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Lower Ordovician rocks, undivided (dolostone (dolomite)), Lower Ordovician in age, covering about 37% of the county. Next is the Middle Ordovician rocks, undivided at 12%.

Against the rest of Minnesota

Blue Earth County ranks 14 of 87 in Minnesota for soluble rock at the surface, and sits above 0% of US counties on that measure.