County soil summary

Soil types in Butte County, California

The most widespread soils are Esquon, Dunstone and Lofgren; the most common drainage class is well drained (42% of the land), and typical topsoil pH is 6.3.

Mapped soil survey data 1.4 million acres of mapped land · 166 named soil series

About 955,000 acres of Butte County lie in multi-county soil survey areas (CA612, CA708, CA713) that the soil survey does not split by county. Those acres, often public forest or desert land, are counted in the California totals but not in the figures below.

Well or moderately well drained
60%
of land · state 81%
Typical topsoil pH
6.3
slightly acidic · state 6.7
Septic fields very limited
81%
of land · state 79%
Subject to flooding
23%
of land, any frequency · state 11%

Most common soils in Butte County

Share of mapped land

A county is a patchwork of many soils. These 8 cover 25% of the mapped land; 166 named soil series are mapped here in all.

Most common soils in Butte County by share of mapped land
Soil Share of land Drainage Topsoil pH
UnnamedGeneral soil group, not a named series 4.3% — —
Rock outcropLand type, not a soil series 4.2% — —
Esquon 3.7% Poorly drained 4.5
Holland familyGeneral soil group, not a named series 3.1% — —
XerorthentsGeneral soil group, not a named series 2.9% — —
Ultic HaploxeralfsGeneral soil group, not a named series 2.6% — —
Dunstone 2.6% Well drained 6.0
Lofgren 2.0% Poorly drained 5.1

Drainage and pH for a series are its typical values across all its mapped acres nationwide. A dash means the row is not a soil series.

What this means

What the soils in Butte County mean for gardens, lawns and septic systems

For your garden

Typical topsoil in Butte County is slightly acidic: pH 6.3 (most land between 5.5 and 7.0), the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 67% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is gravelly loam (16% of the land).

60% of the land is moderately well to excessively drained, which suits most garden plants.

For your lawn and yard

On 60% of the land, 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 81% of the land in Butte County very limited, 2% somewhat limited and 0% not limited (17% not rated, such as urban land, pits or water).

That is close to the state as a whole (79% very 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.

Flooding is mapped on 23% of the land (6% occasional, 2% 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.

Drainage

How long the soil stays wet

The most common drainage class is well drained (42%). 60% of the land is moderately well drained or better, compared with 81% across California.

Excessively drained 1%
Somewhat excessively drained 7%
Well drained 42%
Moderately well drained 9%
Somewhat poorly drained 9%
Poorly drained 15%
Very poorly drained 0%
Not rated 17%
Natural drainage class, share of mapped land in Butte County. Scale 0 to 100% of mapped land.
Show as a table
Natural drainage class, share of mapped land in Butte County.
CategoryButte CountyCalifornia
Excessively drained1.3%7.7%
Somewhat excessively drained7.3%17.6%
Well drained41.9%50.7%
Moderately well drained9.4%4.7%
Somewhat poorly drained8.9%2.5%
Poorly drained14.5%2.0%
Very poorly drained0.0%0.7%
Not rated16.7%14.2%

Septic absorption fields

NRCS rating for conventional drain fields

The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.

Not limited 0%
Somewhat limited 2%
Very limited 81%
Not rated 17%
Septic tank absorption field rating, share of mapped land in Butte County. Scale 0 to 100% of mapped land.
Show as a table
Septic tank absorption field rating, share of mapped land in Butte County.
CategoryButte CountyCalifornia
Not limited0.0%4.3%
Somewhat limited1.5%3.6%
Very limited81.1%79.2%
Not rated17.4%12.9%

Rain, runoff and water table

Hydrologic soil group, flooding, seasonal water table

Hydrologic soil group

How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.

A: fast infiltration (mostly sandy or gravelly) 11%
B: moderate infiltration 14%
C: slow infiltration 26%
D: very slow infiltration (clayey, shallow or wet) 30%
A/D: D as is, A if drained <1%
B/D: D as is, B if drained 0%
C/D: D as is, C if drained 3%
Not rated 15%
Hydrologic soil group, share of mapped land in Butte County. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group, share of mapped land in Butte County.
CategoryButte CountyCalifornia
A: fast infiltration (mostly sandy or gravelly)11.3%20.5%
B: moderate infiltration13.9%12.5%
C: slow infiltration26.4%22.7%
D: very slow infiltration (clayey, shallow or wet)30.4%30.3%
A/D: D as is, A if drained0.1%0.3%
B/D: D as is, B if drained0.0%0.3%
C/D: D as is, C if drained2.7%0.9%
Not rated15.2%12.6%

Flooding

No flooding 50%
Rare or very rare 15%
Occasional 6%
Frequent or very frequent 2%
Not reported 26%
Most frequent flooding class in any month, share of mapped land in Butte County. Scale 0 to 100% of mapped land.
Show as a table
Most frequent flooding class in any month, share of mapped land in Butte County.
CategoryButte CountyCalifornia
No flooding50.4%77.1%
Rare or very rare14.8%8.2%
Occasional6.4%1.6%
Frequent or very frequent2.2%1.0%
Not reported26.2%12.1%

Seasonal high water table

Within 18 inches at some time of year 11%
18 inches to 3.3 feet 14%
Deeper than 3.3 feet or none reported 49%
Not reported 26%
Shallowest depth to a saturated zone in any month, share of mapped land in Butte County. Scale 0 to 100% of mapped land.
Show as a table
Shallowest depth to a saturated zone in any month, share of mapped land in Butte County.
CategoryButte CountyCalifornia
Within 18 inches at some time of year10.7%2.6%
18 inches to 3.3 feet13.9%1.9%
Deeper than 3.3 feet or none reported49.1%86.9%
Not reported26.2%8.6%

Topsoil pH and texture

First mineral layer of each soil

Typical topsoil pH is 6.3 (slightly acidic); 80% of rated land falls between 5.5 and 7.0. Median topsoil organic matter is 3%.

Strongly acidic (below 5.5) 7%
Moderately to slightly acidic (5.5–6.4) 37%
Near neutral (6.5–7.3) 33%
Alkaline (7.4 and up) 4%
Not reported 18%
Topsoil pH band, share of mapped land in Butte County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil pH band, share of mapped land in Butte County.
CategoryButte CountyCalifornia
Strongly acidic (below 5.5)6.8%3.1%
Moderately to slightly acidic (5.5–6.4)37.4%22.8%
Near neutral (6.5–7.3)33.3%25.2%
Alkaline (7.4 and up)4.4%30.6%
Not reported18.1%18.2%

Texture

Sandy 4%
Loamy (loam, silt loam and similar) 67%
Clayey (40%+ clay) 12%
Organic (muck or peat) 0%
Not reported (rock, urban land, etc.) 18%
Topsoil texture group, share of mapped land in Butte County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil texture group, share of mapped land in Butte County.
CategoryButte CountyCalifornia
Sandy3.6%21.3%
Loamy (loam, silt loam and similar)66.7%56.7%
Clayey (40%+ clay)11.6%3.9%
Organic (muck or peat)0.0%0.2%
Not reported (rock, urban land, etc.)18.0%18.0%

Most common surface textures: gravelly loam 16% · loam 15% · clay 11% · sandy loam 6% · very gravelly loam 5%.

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
Butte County, California (FIPS 06007): 1,372,192 acres of mapped land, 28,013 acres of open water excluded. State comparisons pool all mapped land in California.
Method
Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.

Independent reference site. No government affiliation or endorsement.