Soil series profile

Skagit soil series

Skagit is a poorly drained soil with a silt loam surface, mapped on 23,352 acres in 1 county in WA. Hydrologic group B/D.

#9602 by mapped area fine-silty Typic Fluvaquents (Entisols)

Drainage class: Poorly drained
Hydrologic group: B/D
Typical topsoil pH: 6.5
Mapped area: 23k

Typical Skagit 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 Skagit horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–12 in (H1)	Silt loam	6.5	21%	11%	4%
12–50 in (H2)	Silt loam	6.5	27%	9%	2.25%
50–60 in (H3)	Very fine sandy loam	6.5	18%	59%	0.75%

Representative values from the most extensive Skagit map unit (Skagit silt loam, survey area WA657). 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 Skagit soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Skagit soils is slightly acidic: pH 6.5, the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 88% of mapped Skagit acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (88% of mapped Skagit acres).

100% of mapped Skagit acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.

For lawns and yards

On 88% 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.

A seasonal high water table comes within 18 inches of the surface on 100% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.

For a septic system

For conventional septic absorption fields, NRCS rates 88% of the acres in mapped Skagit soils very limited, 0% somewhat limited and 0% not limited (12% not rated, such as urban land, pits or water).

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.

Flooding is mapped on 100% of the acres (0% occasional, 12% 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 Skagit soil is found

Mapped acres

Skagit is mapped in Washington.

Counties with the most mapped Skagit soil
County	Acres	Share of county land
Skagit County, WA	23,352	3.0%

Septic absorption fields

NRCS rating, share of Skagit acres

Not limited 0%

Somewhat limited 0%

Very limited 88%

Not rated 12%

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

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Septic tank absorption field rating across mapped Skagit acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	88.2%
Not rated	11.8%

Drainage, water table and flooding

Share of Skagit acres

Depth to seasonal high water table: About 1.2 feet (14 in) (median where reported); within 18 inches on 100% of acres.
Flooding: Mapped as flooding on 100% of acres (0% occasional, 12% frequent).
Slope: Typically 1–1% (median 1%).
Topsoil organic matter: Median 4%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 0%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 100%

Very poorly drained 0%

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

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Drainage class across mapped Skagit acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	0.0%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	100.0%
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) 0%

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

B/D: D as is, B if drained 88%

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

Not rated 12%

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

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Hydrologic soil group across mapped Skagit 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)	0.0%
A/D: D as is, A if drained	0.0%
B/D: D as is, B if drained	88.2%
C/D: D as is, C if drained	0.0%
Not rated	11.8%

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 Skagit (component kind "Series") in SSURGO: 23,352 acres.
Method: Shares are by mapped acres of Skagit components. The profile comes from the single largest Skagit component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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