County soil summary
Soil types in Oakland County, Michigan
The most widespread soils are Marlette, Spinks and Riddles; the most common drainage class is well drained (49% of the land), and typical topsoil pH is 6.5.
- Well or moderately well drained
- 53% of land · state 53%
- Typical topsoil pH
- 6.5 slightly acidic · state 6.0
- Septic fields very limited
- 79% of land · state 95%
- Subject to flooding
- 1% of land, any frequency · state 2%
Most common soils in Oakland County
Share of mapped land
A county is a patchwork of many soils. These 8 cover 60% of the mapped land; 76 named soil series are mapped here in all.
| Soil | Share of land | Drainage | Topsoil pH |
|---|---|---|---|
| Marlette | 13.8% | Moderately well drained | 6.1 |
| Urban landLand type, not a soil series | 12.0% | — | — |
| Spinks | 7.3% | Well drained | 6.0 |
| Riddles | 6.3% | Well drained | 6.5 |
| Fox | 6.3% | Well drained | 6.2 |
| Houghton | 5.3% | Very poorly drained | Not reported |
| Oshtemo | 5.0% | Well drained | 6.0 |
| Capac | 3.8% | Somewhat poorly drained | 6.6 |
What this means
What the soils in Oakland County mean for gardens, lawns and septic systems
For your garden
Typical topsoil in Oakland County is slightly acidic: pH 6.5 (most land between 6.2 and 6.7), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 48% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is sandy loam (35% of the land).
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.
A seasonal high water table comes within 18 inches of the surface on 33% of the land, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For a septic system
For conventional septic absorption fields, NRCS rates 79% of the land in Oakland County very limited, 8% somewhat limited and 1% not limited (11% not rated, such as urban land, pits or water).
Statewide, 95% of the land is very limited, so Oakland County is less 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.
Drainage
How long the soil stays wet
The most common drainage class is well drained (49%). 53% of the land is moderately well drained or better, compared with 53% across Michigan.
Show as a table
| Category | Oakland County | Michigan |
|---|---|---|
| Excessively drained | 2.7% | 9.2% |
| Somewhat excessively drained | 0.0% | 8.5% |
| Well drained | 48.8% | 24.7% |
| Moderately well drained | 1.4% | 10.7% |
| Somewhat poorly drained | 14.3% | 18.0% |
| Poorly drained | 3.8% | 13.2% |
| Very poorly drained | 16.4% | 14.1% |
| Not rated | 12.6% | 1.7% |
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.
Show as a table
| Category | Oakland County | Michigan |
|---|---|---|
| Not limited | 1.4% | 0.4% |
| Somewhat limited | 8.0% | 3.7% |
| Very limited | 79.4% | 94.7% |
| Not rated | 11.2% | 1.2% |
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.
Show as a table
| Category | Oakland County | Michigan |
|---|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 21.6% | 29.1% |
| B: moderate infiltration | 15.2% | 8.5% |
| C: slow infiltration | 16.8% | 8.0% |
| D: very slow infiltration (clayey, shallow or wet) | 4.4% | 8.7% |
| A/D: D as is, A if drained | 17.8% | 17.8% |
| B/D: D as is, B if drained | 6.6% | 10.0% |
| C/D: D as is, C if drained | 6.4% | 16.2% |
| Not rated | 11.2% | 1.6% |
Flooding
Show as a table
| Category | Oakland County | Michigan |
|---|---|---|
| No flooding | 86.0% | 96.1% |
| Rare or very rare | 0.0% | 0.2% |
| Occasional | 0.0% | 0.4% |
| Frequent or very frequent | 1.4% | 1.8% |
| Not reported | 12.6% | 1.5% |
Seasonal high water table
Show as a table
| Category | Oakland County | Michigan |
|---|---|---|
| Within 18 inches at some time of year | 33.3% | 49.2% |
| 18 inches to 3.3 feet | 2.6% | 6.2% |
| Deeper than 3.3 feet or none reported | 62.7% | 44.1% |
| Not reported | 1.4% | 0.5% |
Topsoil pH and texture
First mineral layer of each soil
Typical topsoil pH is 6.5 (slightly acidic); 80% of rated land falls between 6.2 and 6.7. Median topsoil organic matter is 2%.
Show as a table
| Category | Oakland County | Michigan |
|---|---|---|
| Strongly acidic (below 5.5) | 0.0% | 29.3% |
| Moderately to slightly acidic (5.5–6.4) | 30.6% | 33.6% |
| Near neutral (6.5–7.3) | 45.0% | 23.0% |
| Alkaline (7.4 and up) | 3.0% | 4.2% |
| Not reported | 21.4% | 9.9% |
Texture
Show as a table
| Category | Oakland County | Michigan |
|---|---|---|
| Sandy | 30.0% | 42.8% |
| Loamy (loam, silt loam and similar) | 48.2% | 40.2% |
| Clayey (40%+ clay) | 0.0% | 0.4% |
| Organic (muck or peat) | 9.2% | 14.3% |
| Not reported (rock, urban land, etc.) | 12.6% | 2.2% |
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
- Oakland County, Michigan (FIPS 26125): 551,029 acres of mapped land, 29,694 acres of open water excluded. State comparisons pool all mapped land in Michigan.
- 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.