Soil series profile
Hugo soil series
Hugo is a well drained soil with a very gravelly loam surface, mapped on 162,495 acres in 5 counties in CA. Hydrologic group B.
- Drainage class
- Well drained 99% of mapped acres
- Hydrologic group
- B 88% of mapped acres
- Typical topsoil pH
- 6.5 slightly acidic · range 6.1–6.5
- Mapped area
- 162k acres in 5 counties, 1 state
Typical Hugo profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–8 in (H1) | Very gravelly loam | 6.5 | 24% | 39% | 4% |
| 8–31 in (H2) | Gravelly sandy clay loam | 5.8 | 28% | 55% | 1.35% |
| 31–48 in (H3) | Gravelly clay loam | 5.3 | 28% | 37% | 0.75% |
| 48–59 in (H4) | Weathered bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Hugo soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Hugo soils is slightly acidic: pH 6.5 (most land between 6.1 and 6.5), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 99% of mapped Hugo acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is very gravelly loam (72% of mapped Hugo acres).
99% of mapped Hugo acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.
For a septic system
For conventional septic absorption fields, NRCS rates 99% of the acres in mapped Hugo soils very limited, <1% somewhat limited and 0% not limited (1% 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 Hugo soil is found
Mapped acres
Hugo is mapped in California.
| County | Acres | Share of county land |
|---|---|---|
| Sonoma County, CA | 140,255 | 13.8% |
| San Mateo County, CA | 19,944 | 7.0% |
| Glenn County, CA | 1,962 | 0.2% |
| Tehama County, CA | 251 | 0.0% |
| Mendocino County, CA | 83 | 0.0% |
Septic absorption fields
NRCS rating, share of Hugo acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.1% |
| Very limited | 98.5% |
| Not rated | 1.4% |
Drainage, water table and flooding
Share of Hugo 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 40–63% (median 63%).
- Topsoil organic matter
- Median 4%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 98.6% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
| Not rated | 1.4% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 6.8% |
| B: moderate infiltration | 87.7% |
| C: slow infiltration | 4.1% |
| 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% |
| Not rated | 1.4% |
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
- All map unit components named Hugo (component kind "Series") in SSURGO: 162,495 acres.
- Method
- Shares are by mapped acres of Hugo components. The profile comes from the single largest Hugo component. Full methodology.