Sinkhole risk in Santa Fe County, NM: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 18%
At or near the surface: 18%
Buried under cover: 0%

What to do about a house in Santa Fe County

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 346 of Santa Fe County's 1,910 square miles on soluble rock, 346 of them with the rock at or near the surface. With about 157,765 residents (83 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 392 map points about 2.2 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: why gypsum and salt move faster than limestone, and the signs to look for and how an inspection works.

Counties around Santa Fe County

The nearest county rated sinkhole country is Eddy County, NM, about 232 miles southeast. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Los Alamos County, NM 31 mi northwest · 0% at surface
Bernalillo County, NM 51 mi southwest · 6% at surface
Sandoval County, NM 53 mi west · 18% at surface
San Miguel County, NM 65 mi east · 28% at surface
Torrance County, NM 66 mi south · 28% at surface
Mora County, NM 67 mi northeast · 19% at surface

Which formation it is

The largest mapped soluble unit here is the Chinle Group (medium-grained mixed clastic), Triassic in age, covering about 11% of the county. Next is the San Andres Formation at 3%.

13% of the county sits on gypsum or salt, which dissolves in years rather than millennia. That share matters more than its size suggests.

Against the rest of New Mexico

Santa Fe County ranks 12 of 33 in New Mexico for soluble rock at the surface, and sits above 73% of US counties on that measure.