Soil series profile
Bressa soil series
Bressa is a well drained soil with a silt loam surface, mapped on 72,802 acres in 4 counties in CA. Hydrologic group C.
- Drainage class
- Well drained 94% of mapped acres
- Hydrologic group
- C 94% of mapped acres
- Typical topsoil pH
- 6.7 neutral · range 6.7–6.7
- Mapped area
- 73k acres in 4 counties, 1 state
Typical Bressa profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–10 in (H1) | Silt loam | 6.7 | 20% | 27% | 1.75% |
| 10–33 in (H2) | Silty clay loam | 6.5 | 31% | 15% | 0.75% |
| 33–60 in (H3) | Bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Bressa soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Bressa soils is neutral: pH 6.7, the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 94% of mapped Bressa acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (94% of mapped Bressa acres).
94% of mapped Bressa 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 Bressa 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 Bressa soil is found
Mapped acres
Bressa is mapped in California.
| County | Acres | Share of county land |
|---|---|---|
| Napa County, CA | 67,771 | 15.4% |
| Lake County, CA | 4,249 | 0.5% |
| Yolo County, CA | 577 | 0.1% |
| Solano County, CA | 205 | 0.0% |
Septic absorption fields
NRCS rating, share of Bressa acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 93.8% |
| Not rated | 6.2% |
Drainage, water table and flooding
Share of Bressa 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 23–63% (median 40%).
- Topsoil organic matter
- Median 1.8%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 93.8% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
| Not rated | 6.2% |
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 | 93.8% |
| 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 | 6.2% |
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 Bressa (component kind "Series") in SSURGO: 72,802 acres.
- Method
- Shares are by mapped acres of Bressa components. The profile comes from the single largest Bressa component. Full methodology.