Soil series profile
Laughlin soil series
Laughlin is a well drained soil with a loam surface, mapped on 65,250 acres in 3 counties in CA. Hydrologic group C.
- Drainage class
- Well drained 94% of mapped acres
- Hydrologic group
- C 92% of mapped acres
- Typical topsoil pH
- 5.8 moderately acidic · range 5.8–5.8
- Mapped area
- 65k acres in 3 counties, 1 state
Typical Laughlin profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–4 in (H1) | Loam | 5.8 | 22% | 41% | 3.5% |
| 4–22 in (H2) | Sandy clay loam | 5.6 | 25% | 57% | 1.5% |
| 22–32 in (H3) | Unweathered bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Laughlin soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Laughlin soils is moderately acidic: pH 5.8. Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.
Loamy topsoil (loam, silt loam and similar) covers 94% of mapped Laughlin acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loam (94% of mapped Laughlin acres).
94% of mapped Laughlin acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 94% 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 94% of the acres in mapped Laughlin soils very limited, 0% somewhat limited and 0% not limited (6% 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.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Laughlin soil is found
Mapped acres
Laughlin is mapped in California.
| County | Acres | Share of county land |
|---|---|---|
| Sonoma County, CA | 59,997 | 5.9% |
| San Mateo County, CA | 5,243 | 1.8% |
| Napa County, CA | 9 | 0.0% |
Septic absorption fields
NRCS rating, share of Laughlin acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 93.7% |
| Not rated | 6.3% |
Drainage, water table and flooding
Share of Laughlin 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 33–63% (median 40%).
- Topsoil organic matter
- Median 3.5%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 93.7% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
| Not rated | 6.3% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 0.0% |
| C: slow infiltration | 91.5% |
| D: very slow infiltration (clayey, shallow or wet) | 2.2% |
| 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% |
| Not rated | 6.3% |
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 Laughlin (component kind "Series") in SSURGO: 65,250 acres.
- Method
- Shares are by mapped acres of Laughlin components. The profile comes from the single largest Laughlin component. Full methodology.