County soil summary

Soil types in Santa Cruz County, California

The most widespread soils are Ben Lomond, Felton and Lompico; the most common drainage class is well drained (57% of the land), and typical topsoil pH is 6.5.

Mapped soil survey data 275,000 acres of mapped land · 54 named soil series

Well or moderately well drained
81%
of land · state 81%
Typical topsoil pH
6.5
slightly acidic · state 6.7
Septic fields very limited
87%
of land · state 79%
Subject to flooding
2%
of land, any frequency · state 11%

Most common soils in Santa Cruz County

Share of mapped land

A county is a patchwork of many soils. These 8 cover 54% of the mapped land; 54 named soil series are mapped here in all.

Most common soils in Santa Cruz County by share of mapped land
Soil Share of land Drainage Topsoil pH
Ben Lomond 12.5% Well drained 6.5
Felton 10.0% Well drained 5.8
Lompico 6.7% Well drained 6.5
Watsonville 5.4% Somewhat poorly drained 6.5
Aptos 5.4% Well drained 6.5
Maymen 5.3% Somewhat excessively drained 5.8
Catelli 4.7% Well drained 6.5
Sur 4.4% Somewhat excessively drained 6.5

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 Santa Cruz County mean for gardens, lawns and septic systems

For your garden

Typical topsoil in Santa Cruz County is slightly acidic: pH 6.5 (most land between 5.8 and 6.7), the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 78% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is sandy loam (33% of the land).

81% of the land is moderately well to excessively drained, which suits most garden plants.

For your lawn and yard

On 52% 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 87% of the land in Santa Cruz County very limited, <1% somewhat limited and <1% not limited (13% not rated, such as urban land, pits or water).

Statewide, 79% of the land is very limited, so Santa Cruz County is more restrictive than typical.

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.

Drainage

How long the soil stays wet

The most common drainage class is well drained (57%). 81% of the land is moderately well drained or better, compared with 81% across California.

Excessively drained <1%
Somewhat excessively drained 18%
Well drained 57%
Moderately well drained 5%
Somewhat poorly drained 5%
Poorly drained 1%
Very poorly drained <1%
Not rated 13%
Natural drainage class, share of mapped land in Santa Cruz County. Scale 0 to 100% of mapped land.
Show as a table
Natural drainage class, share of mapped land in Santa Cruz County.
CategorySanta Cruz CountyCalifornia
Excessively drained0.8%7.7%
Somewhat excessively drained18.3%17.6%
Well drained57.1%50.7%
Moderately well drained4.5%4.7%
Somewhat poorly drained5.4%2.5%
Poorly drained1.1%2.0%
Very poorly drained0.1%0.7%
Not rated12.7%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 <1%
Somewhat limited <1%
Very limited 87%
Not rated 13%
Septic tank absorption field rating, share of mapped land in Santa Cruz County. Scale 0 to 100% of mapped land.
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Septic tank absorption field rating, share of mapped land in Santa Cruz County.
CategorySanta Cruz CountyCalifornia
Not limited0.4%4.3%
Somewhat limited0.2%3.6%
Very limited86.9%79.2%
Not rated12.6%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) 20%
B: moderate infiltration 15%
C: slow infiltration 33%
D: very slow infiltration (clayey, shallow or wet) 19%
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 0%
Not rated 13%
Hydrologic soil group, share of mapped land in Santa Cruz County. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group, share of mapped land in Santa Cruz County.
CategorySanta Cruz CountyCalifornia
A: fast infiltration (mostly sandy or gravelly)20.4%20.5%
B: moderate infiltration14.5%12.5%
C: slow infiltration33.1%22.7%
D: very slow infiltration (clayey, shallow or wet)19.1%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 drained0.0%0.9%
Not rated12.7%12.6%

Flooding

No flooding 83%
Rare or very rare 2%
Occasional 0%
Frequent or very frequent <1%
Not reported 14%
Most frequent flooding class in any month, share of mapped land in Santa Cruz County. Scale 0 to 100% of mapped land.
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Most frequent flooding class in any month, share of mapped land in Santa Cruz County.
CategorySanta Cruz CountyCalifornia
No flooding83.4%77.1%
Rare or very rare2.0%8.2%
Occasional0.0%1.6%
Frequent or very frequent0.4%1.0%
Not reported14.2%12.1%

Seasonal high water table

Within 18 inches at some time of year <1%
18 inches to 3.3 feet 1%
Deeper than 3.3 feet or none reported 99%
Not reported <1%
Shallowest depth to a saturated zone in any month, share of mapped land in Santa Cruz County. Scale 0 to 100% of mapped land.
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Shallowest depth to a saturated zone in any month, share of mapped land in Santa Cruz County.
CategorySanta Cruz CountyCalifornia
Within 18 inches at some time of year0.1%2.6%
18 inches to 3.3 feet1.1%1.9%
Deeper than 3.3 feet or none reported98.7%86.9%
Not reported0.1%8.6%

Topsoil pH and texture

First mineral layer of each soil

Typical topsoil pH is 6.5 (slightly acidic); 80% of rated land falls between 5.8 and 6.7. Median topsoil organic matter is 2%.

Strongly acidic (below 5.5) <1%
Moderately to slightly acidic (5.5–6.4) 20%
Near neutral (6.5–7.3) 65%
Alkaline (7.4 and up) <1%
Not reported 15%
Topsoil pH band, share of mapped land in Santa Cruz County. Scale 0 to 100% of mapped land.
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Topsoil pH band, share of mapped land in Santa Cruz County.
CategorySanta Cruz CountyCalifornia
Strongly acidic (below 5.5)0.2%3.1%
Moderately to slightly acidic (5.5–6.4)19.5%22.8%
Near neutral (6.5–7.3)65.3%25.2%
Alkaline (7.4 and up)0.4%30.6%
Not reported14.6%18.2%

Texture

Sandy 6%
Loamy (loam, silt loam and similar) 78%
Clayey (40%+ clay) 1%
Organic (muck or peat) 0%
Not reported (rock, urban land, etc.) 14%
Topsoil texture group, share of mapped land in Santa Cruz County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil texture group, share of mapped land in Santa Cruz County.
CategorySanta Cruz CountyCalifornia
Sandy6.3%21.3%
Loamy (loam, silt loam and similar)78.3%56.7%
Clayey (40%+ clay)1.3%3.9%
Organic (muck or peat)0.0%0.2%
Not reported (rock, urban land, etc.)14.1%18.0%

Most common surface textures: sandy loam 33% · loam 24% · fine sandy loam 7% · gravelly sandy loam 5% · stony sandy loam 4%.

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
Santa Cruz County, California (FIPS 06087): 274,752 acres of mapped land, 1,400 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.

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