Sinkhole risk in Douglas County, CO: 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: 1%
At or near the surface: 1%
Buried under cover: 0%

What to do about a house in Douglas County

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

That works out to roughly 11 of Douglas County's 841 square miles on soluble rock, 11 of them with the rock at or near the surface. With about 393,995 residents (469 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 318 map points about 1.6 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Douglas County

The nearest county rated sinkhole country is Dawes County, NE, about 252 miles north. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Jefferson County, CO 24 mi northwest · 2% at surface
Denver County, CO 30 mi north · 0% at surface
Teller County, CO 34 mi southwest · under 1% at surface
Arapahoe County, CO 39 mi northeast · 0% at surface
El Paso County, CO 40 mi southeast · 2% at surface
Elbert County, CO 43 mi east · 0% at surface

Which formation it is

The largest mapped soluble unit here is the Lykins Fm and Lyons Sandstone (sandstone), Triassic-Permian in age, covering about under 1% of the county. Next is the Leadville Limestone, Williams Canyon Limestone , Manitou Limestone, and Sawatch Quartzite at under 1%.

Against the rest of Colorado

Douglas County ranks 28 of 64 in Colorado for soluble rock at the surface, and sits above 56% of US counties on that measure.