Soil series profile
Lofgren soil series
Lofgren is a poorly drained soil with a clay surface, mapped on 27,335 acres in 1 county in CA. Hydrologic group D.
- Drainage class
- Poorly drained 94% of mapped acres
- Hydrologic group
- D 94% of mapped acres
- Typical topsoil pH
- 5.1 strongly acidic · range 5.1–6.0
- Mapped area
- 27k acres in 1 county, 1 state
Typical Lofgren profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–5 in (Ap) | Clay | 5.1 | 66% | 7% | 2.64% |
| 5–12 in (Bssg1) | Clay | 6.7 | 65% | 9% | 1.22% |
| 12–29 in (Bssg2) | Clay | 7.5 | 66% | 8% | 0.71% |
| 29–38 in (Bkssg) | Clay | 8.1 | 65% | 10% | 0.55% |
| 38–44 in (Bkg) | Clay | 8.1 | 61% | 13% | 0.62% |
| 44–47 in (2Bkq) | Clay loam | 8.5 | 29% | 34% | 0.38% |
| 47–62 in (2Bkqm1) | Cemented material | 8.7 | 16% | 50% | 0.21% |
| 62–82 in (2Bkqm2) | Cemented material | 8.4 | 17% | 50% | 0.09% |

What this means
What Lofgren soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Lofgren soils is strongly acidic: pH 5.1 (most land between 5.1 and 6.0). Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.
Clayey topsoil covers 94% of mapped Lofgren acres. Clay holds water and nutrients but drains slowly and compacts if worked wet: add compost, avoid tilling soggy soil and consider raised beds. The most common surface texture is clay (94% of mapped Lofgren acres).
94% of mapped Lofgren acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.
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 Lofgren 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.
Flooding is mapped on 94% of the acres (30% occasional, 0% frequent).
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Lofgren soil is found
Mapped acres
Lofgren is mapped in California.
| County | Acres | Share of county land |
|---|---|---|
| Butte County, CA | 27,335 | 2.0% |
Septic absorption fields
NRCS rating, share of Lofgren acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 94.4% |
| Not rated | 5.6% |
Drainage, water table and flooding
Share of Lofgren acres
- Depth to seasonal high water table
- About 1.7 feet (20 in) (median where reported).
- Flooding
- Mapped as flooding on 94% of acres (30% occasional, 0% frequent).
- Slope
- Typically 0–0% (median 0%).
- Topsoil organic matter
- Median 2.6%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 0.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 94.4% |
| Very poorly drained | 0.0% |
| Not rated | 5.6% |
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 | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 94.4% |
| 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 | 5.6% |
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 Lofgren (component kind "Series") in SSURGO: 27,335 acres.
- Method
- Shares are by mapped acres of Lofgren components. The profile comes from the single largest Lofgren component. Full methodology.