Soil series profile

Raz soil series

Raz is a well drained soil with a very cobbly loam surface, mapped on 575,582 acres in 4 counties across 2 states. Hydrologic group D.

#457 by mapped area loamy Xeric Haplodurids (Aridisols)

Drainage class: Well drained
Hydrologic group: D
Typical topsoil pH: 7.6
Mapped area: 576k

Typical Raz 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).

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Typical Raz horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–2 in (A)	Very cobbly loam	7.6	24%	39%	1.5%
2–7 in (Bk)	Gravelly clay loam	7.9	28%	35%	0.75%
7–12 in (Bkq)	Clay loam	8.2	28%	35%	0.25%
12–23 in (Bkqm)	Cemented material	Not reported	Not reported	Not reported	Not reported
23–33 in (2R)	Bedrock	Not reported	Not reported	Not reported	Not reported

Representative values from the most extensive Raz map unit (Raz-Brace complex, 2 to 20 percent slopes, harney area, mlra 23, survey area OR628). 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 Raz soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Raz soils is slightly alkaline: pH 7.6 (most land between 7.5 and 7.6). 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 >99% of mapped Raz acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is very cobbly loam (97% of mapped Raz acres).

100% of mapped Raz acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 100% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.

For a septic system

For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Raz soils very limited, 0% somewhat limited and 0% not limited.

Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.

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 Raz soil is found

Mapped acres

Raz is mapped in Oregon and Nevada.

Counties with the most mapped Raz soil
County	Acres	Share of county land
Harney County, OR	361,031	6.8%
Lake County, OR	214,487	5.2%
Washoe County, NV	42	0.0%
Humboldt County, NV	22	0.0%

Septic absorption fields

NRCS rating, share of Raz acres

Not limited 0%

Somewhat limited 0%

Very limited 100%

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

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Septic tank absorption field rating across mapped Raz acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	100.0%

Drainage, water table and flooding

Share of Raz acres

Depth to seasonal high water table: None reported within about 6.5 feet (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 6–11% (median 11%).
Topsoil organic matter: Median 1.5%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 100%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

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

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Drainage class across mapped Raz acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	100.0%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%

B: moderate infiltration 0%

C: slow infiltration 0%

D: very slow infiltration (clayey, shallow or wet) 100%

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%

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

Show as a table

Hydrologic soil group across mapped Raz acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.0%
C: slow infiltration	0.0%
D: very slow infiltration (clayey, shallow or wet)	100.0%
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%

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 Raz (component kind "Series") in SSURGO: 575,582 acres.
Method: Shares are by mapped acres of Raz components. The profile comes from the single largest Raz component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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