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

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 439 of Dodge County's 439 square miles on soluble rock. With about 21,242 residents (48 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 398 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 100% under cover still counts, and how these percentages are measured.

Counties around Dodge County

The nearest county rated sinkhole country is Vernon County, WI, about 106 miles east. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Steele County, MN 18 mi west · 0% at surface
Olmsted County, MN 23 mi east · 6% at surface
Mower County, MN 25 mi south · 0% at surface
Goodhue County, MN 28 mi north · 22% at surface
Rice County, MN 31 mi northwest · 0% at surface
Freeborn County, MN 34 mi southwest · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Upper and Middle Ordovician rocks, undivided (limestone), Late and Middle Ordovician in age, covering about 89% of the county. Next is the Middle Ordovician rocks, undivided at 7%.

Against the rest of Minnesota

Dodge County ranks 27 of 87 in Minnesota for soluble rock at the surface, and sits above 0% of US counties on that measure.