State soil summary
Soil types in Hawaii
The most widespread soil series in Hawaii are Kaiwiki, Keei, Honokaa. Pick a county below, or enter a ZIP code for the county you live in.
- Well or moderately well drained
- 87% of mapped land
- Typical topsoil pH
- 6.0 moderately acidic · most land 4.3–7.0
- Septic fields very limited
- 93% <1% not limited
- Subject to flooding
- 7% of land, any frequency
Hawaii counties
3 county reports, by population
| County | Most common soil | Well drained | Topsoil pH | Septic very limited |
|---|---|---|---|---|
| Honolulu County | Helemano | 89% | 5.8 | 86% |
| Hawaii County | Kaiwiki | 87% | 6.0 | 95% |
| Maui County | Molokai | 88% | 6.3 | 91% |
What this means
What Hawaii soils mean for gardens, lawns and septic systems
For gardens
Typical topsoil in Hawaii is moderately acidic: pH 6.0 (most land between 4.3 and 7.0). Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.
Loamy topsoil (loam, silt loam and similar) covers 59% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is bedrock (19% of the land).
87% of the land is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 51% 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.
For septic systems
For conventional septic absorption fields, NRCS rates 93% of the land in Hawaii very limited, 5% somewhat limited and <1% not limited (2% 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 7% of the land (4% occasional, <1% frequent).
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Statewide mix
Share of all mapped land
Drainage
Show as a table
| Category | Share of land |
|---|---|
| Excessively drained | 13.2% |
| Somewhat excessively drained | 3.1% |
| Well drained | 65.8% |
| Moderately well drained | 4.6% |
| Somewhat poorly drained | 0.6% |
| Poorly drained | 1.9% |
| Very poorly drained | 0.9% |
| Not rated | 9.8% |
Septic absorption fields
Show as a table
| Category | Share of land |
|---|---|
| Not limited | 0.2% |
| Somewhat limited | 5.1% |
| Very limited | 93.1% |
| Not rated | 1.6% |
Topsoil pH
Show as a table
| Category | Share of land |
|---|---|
| Strongly acidic (below 5.5) | 26.3% |
| Moderately to slightly acidic (5.5–6.4) | 20.5% |
| Near neutral (6.5–7.3) | 29.3% |
| Alkaline (7.4 and up) | 1.7% |
| Not reported | 22.3% |
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
- Hawaii: 4,070,194 acres of mapped land in 5 counties, pooled (not an average of county figures).
- 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.