Soil series profile

Woodburn soil series

Woodburn is a moderately well drained soil with a silt loam surface, mapped on 225,009 acres in 8 counties in OR. Hydrologic group C.

#1572 by mapped area fine-silty Aquultic Argixerolls (Mollisols)

Drainage class: Moderately well drained
Hydrologic group: C
Typical topsoil pH: 6.1
Mapped area: 225k

Typical Woodburn 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 Woodburn horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–17 in (H1)	Silt loam	6.1	15%	14%	4%
17–32 in (H2)	Silty clay loam	6.1	28%	7%	1.75%
32–68 in (H3)	Silt loam	6.1	23%	7%	0.25%

Representative values from the most extensive Woodburn map unit (Woodburn silt loam, 0 to 3 percent slopes, survey area OR643). 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 Woodburn soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Woodburn soils is slightly acidic: pH 6.1 (most land between 5.9 and 6.1), the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Woodburn acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (100% of mapped Woodburn acres).

100% of mapped Woodburn 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 Woodburn 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 Woodburn soil is found

Mapped acres

Woodburn is mapped in Oregon.

Counties with the most mapped Woodburn soil
County	Acres	Share of county land
Marion County, OR	66,899	13.3%
Yamhill County, OR	50,182	11.4%
Washington County, OR	30,059	7.6%
Linn County, OR	26,800	3.2%
Polk County, OR	22,563	5.4%
Clackamas County, OR	19,946	3.6%
Benton County, OR	8,383	2.2%
Lane County, OR	177	0.0%

Septic absorption fields

NRCS rating, share of Woodburn acres

Not limited 0%

Somewhat limited 0%

Very limited 100%

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

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

Drainage, water table and flooding

Share of Woodburn acres

Depth to seasonal high water table: About 2.0 feet (24 in) (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 2–8% (median 2%).
Topsoil organic matter: Median 4%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 0%

Moderately well drained 100%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

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

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Drainage class across mapped Woodburn acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	0.0%
Moderately well drained	100.0%
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 100%

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%

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

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Hydrologic soil group across mapped Woodburn acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.0%
C: slow infiltration	100.0%
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%

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 Woodburn (component kind "Series") in SSURGO: 225,009 acres.
Method: Shares are by mapped acres of Woodburn components. The profile comes from the single largest Woodburn component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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