HomeNew MexicoSierra County

Sierra County, New Mexico

USDA's soil survey flags shrink-swell clay on 13% of Sierra County's mapped land and a shallow water table under basements on 1%, both below the national shares of 15% and 29%. 94.2% of the county is in drought on the October 13, 2026 Drought Monitor map.

FEMA's flood data list 1 flood losses here since 2016. 43% of homes were built before 1980, against 50% nationally; the median home dates from 1983.

Data as of October 13, 2026 · sources

13%

expansive clay: shrink-swell limits slab homes

1%

high water table: limits basements

94%

in drought, October 13, 2026

43%

of homes built before 1980

Soil under Sierra County

Expansive clay (limits slab homes)12.8%
High water table (limits basements)0.6%
Septic fields very limited73.5%
Clay swell (LEP, by area)3.3%
High-swell land (LEP 6%+)13.9%
Mapped soil2,442,892 acres
Soil seriesShare hereSeries nationally: expansive clay
Nickel11%n/a
Luzena6%n/a
Dona Ana4%n/a
Simona4%n/a
Delnorte4%n/a
Tres Hermanos3%n/a
Doña Ana County: 1%Socorro County: 4%Luna County: 28%Grant County: 38%Catron County: 23%Otero County: 3%El Paso County: 4%Lincoln County: 2%Sierra County Doña AnaSocorroLunaGrantCatronOteroEl PasoLincolnSierra
Sierra County (heavy outline) and nearby counties, shaded by expansive clay share.under 10%10-25%25-40%40-60%60%+

How we count · survey areas NM660 (2025-09-09), NM688 (2025-09-09)

What the numbers mean here

Rain over the 12 months to August 2026: 9.48 in, 2.36 in below the 1991-2020 average year of 11.84 in.

USDA rates 73% of the land very limited for septic absorption fields.

With shrink-swell clay on 13% and a shallow water table on 1% of the land, the soil survey points to neither problem across most of Sierra County; conditions still vary lot by lot.

Drought

94.2% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 52 of the last 52 weeks; the most was 100% of its area, in 49 weeks, most recently on the September 22, 2026 map.

October 21, 2025Share of area in drought, weeklyOctober 13, 2026
Category, October 13, 2026Share of county
D0 abnormally dry or worse100%
D1 moderate drought or worse94.2%
D2 severe or worse0%
D3 extreme or worse0%
D4 exceptional0%

Flood losses since 2016

1 flood losses since 2016, $7,844 paid. The worst year was 2020, with 1.

YearFlood losses
20160
20170
20180
20190
20201
20210
20220
20230
20240
20250
2026 to date0

Rain

Average year, 1991-202011.84 in
12 months to August 20269.48 in (-2.36)
20258.74 in (-3.10)
Wettest year since 18951941: 20.44 in
Driest year since 18951956: 5.56 in
Days with 1 inch or more, normal at ELEPHANT BUTTE DAM (2 mi away)0.8

Homes

Housing units8,200
Median year built1983
Built before 198043%
Built 2000 or later19%
Owner-occupied72%
Median value, owner-occupied$152,600
Single-family detached47%

What repairs cost

Published ranges from cost guides, not quotes. More sources, and where they disagree.

WorkRangeSource
Foundation repair, US $2,200 to $8,200 Fixr, January 27, 2026
Pier-and-beam repair, US $2,000 to $15,000 Fixr, January 27, 2026
Foundation inspection, US $300 to $600 Fixr, January 31, 2025

Nearby counties

PlaceDistanceExpansive clayHigh water table
Doña Ana County, NM 57 mi 1% 1%
Socorro County, NM 62 mi 4% 1%
Luna County, NM 72 mi 28% under 1%
Grant County, NM 74 mi 38% under 1%
Catron County, NM 88 mi 23% under 1%
Otero County, NM 90 mi 3% 2%
El Paso County, TX 108 mi 4% 0%
Lincoln County, NM 109 mi 2% under 1%

Sources: USDA SSURGO (September 9, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status