Soil series profile
Molokai soil series
Molokai is a well drained soil with a silty clay loam surface, mapped on 35,564 acres in 2 counties in HI. Hydrologic group C.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- C 100% of mapped acres
- Typical topsoil pH
- 6.5 slightly acidic · range 6.5–6.5
- Mapped area
- 36k acres in 2 counties, 1 state
Typical Molokai profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–7 in (Ap1) | Silty clay loam | 6.5 | 36% | 17% | 2.5% |
| 7–15 in (Ap2) | Silty clay loam | 6.5 | 36% | 17% | 2.5% |
| 15–35 in (Bto1) | Silty clay loam | 6.5 | 36% | 17% | 0.6% |
| 35–64 in (Bto2) | Silty clay loam | 6.5 | 36% | 17% | 0.6% |
| 64–72 in (Bto3) | Silty clay loam | 6.5 | 36% | 17% | 0.6% |
What this means
What Molokai soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Molokai soils is slightly acidic: pH 6.5, the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 96% of mapped Molokai acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silty clay loam (100% of mapped Molokai acres).
100% of mapped Molokai acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 100% 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 100% of the acres in mapped Molokai soils very limited, 0% somewhat limited and 0% not limited.
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 Molokai soil is found
Mapped acres
Molokai is mapped in Hawaii.
| County | Acres | Share of county land |
|---|---|---|
| Maui County, HI | 28,578 | 3.8% |
| Honolulu County, HI | 6,986 | 1.8% |
Septic absorption fields
NRCS rating, share of Molokai acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 100.0% |
Drainage, water table and flooding
Share of Molokai 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 2–11% (median 5%).
- Topsoil organic matter
- Median 2.5%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
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 | 100.0% |
| 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% |
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 Molokai (component kind "Series") in SSURGO: 35,564 acres.
- Method
- Shares are by mapped acres of Molokai components. The profile comes from the single largest Molokai component. Full methodology.