Soil series profile

Zia soil series

Zia is a somewhat excessively drained soil with a sandy loam surface, mapped on 202,934 acres in 9 counties across 2 states. Hydrologic group A.

#1790 by mapped area coarse-loamy Ustic Torriorthents (Entisols)

Drainage class: Somewhat excessively drained
Hydrologic group: A
Typical topsoil pH: 7.9
Mapped area: 203k

Typical Zia profile

Texture and pH by depth

Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).

Show as a table

Typical Zia horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–3 in (A)	Sandy loam	7.9	15%	66%	1.5%
3–31 in (C1)	Sandy loam	7.9	13%	67%	0.75%
31–65 in (C2)	Fine sandy loam	7.9	13%	70%	0.75%

Representative values from the most extensive Zia map unit (Zia sandy loam, 1 to 5 percent slopes, survey area AZ715). Other map units of this series vary within the series range.

Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Zia soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Zia soils is moderately alkaline: pH 7.9. Acid-loving plants such as blueberries and azaleas struggle without amended beds, and some trees and shrubs show iron chlorosis (yellow leaves with green veins).

Loamy topsoil (loam, silt loam and similar) covers 87% of mapped Zia acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is sandy loam (81% of mapped Zia acres).

62% of mapped Zia acres is excessively or somewhat excessively drained: water moves through fast, so gardens need more frequent watering in dry spells.

For lawns and yards

85% of mapped acres is in hydrologic group A, where water soaks in fast. Lawns there dry out quickly; deeper, less frequent watering and organic matter help.

For a septic system

For conventional septic absorption fields, NRCS rates 5% of the acres in mapped Zia soils very limited, 31% somewhat limited and 62% not limited (2% not rated, such as urban land, pits or water).

Flooding is mapped on 12% of the acres (0% occasional, 0% frequent).

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Where Zia soil is found

Mapped acres

Zia is mapped in New Mexico and Arizona.

Counties with the most mapped Zia soil
County	Acres	Share of county land
Sandoval County, NM	80,110	4.0%
McKinley County, NM	50,627	1.8%
Apache County, AZ	46,434	0.7%
Navajo County, AZ	15,326	0.3%
Santa Fe County, NM	6,433	0.6%
Cibola County, NM	3,181	0.1%
San Juan County, NM	375	0.0%
Valencia County, NM	129	0.0%
Rio Arriba County, NM	45	0.0%

Septic absorption fields

NRCS rating, share of Zia acres

Not limited 62%

Somewhat limited 31%

Very limited 5%

Not rated 2%

Septic tank absorption field rating across mapped Zia acres. Scale 0 to 100% of mapped land.

Show as a table

Septic tank absorption field rating across mapped Zia acres.
Category	Share of acres
Not limited	62.0%
Somewhat limited	31.2%
Very limited	4.8%
Not rated	2.0%

Drainage, water table and flooding

Share of Zia acres

Depth to seasonal high water table: None reported within about 6.5 feet (median where reported).
Flooding: Mapped as flooding on 12% of acres (0% occasional, 0% frequent).
Slope: Typically 2–13% (median 3%).
Topsoil organic matter: Median 1.5%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 62%

Well drained 38%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated <1%

Drainage class across mapped Zia acres. Scale 0 to 100% of mapped land.

Show as a table

Drainage class across mapped Zia acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	61.8%
Well drained	37.9%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	0.3%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 85%

B: moderate infiltration 13%

C: slow infiltration 0%

D: very slow infiltration (clayey, shallow or wet) 0%

A/D: D as is, A if drained 0%

B/D: D as is, B if drained 0%

C/D: D as is, C if drained 0%

Not rated 2%

Hydrologic soil group across mapped Zia acres. Scale 0 to 100% of mapped land.

Show as a table

Hydrologic soil group across mapped Zia acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	84.8%
B: moderate infiltration	13.1%
C: slow infiltration	0.0%
D: very slow infiltration (clayey, shallow or wet)	0.0%
A/D: D as is, A if drained	0.0%
B/D: D as is, B if drained	0.0%
C/D: D as is, C if drained	0.0%
Not rated	2.0%

Sources & data dates

Source: USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
Data date: SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
Scope: All map unit components named Zia (component kind "Series") in SSURGO: 202,934 acres.
Method: Shares are by mapped acres of Zia components. The profile comes from the single largest Zia component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Zia.