Island of Hawaii Area, Hawaii
The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low runoff). This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Island of Hawaii Area, Hawaii.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Lava flows, `a`a, 2 to 20 percent slopes | 214K | Excessively drained | A | Very limited | Very limited |
| Lava flows, pahoehoe, 2 to 20 percent slopes | 116K | C | Very limited | Very limited | |
| Keei slightly decomposed plant material, 3 to 10 percent slopes | 57K | Well drained | D | Very limited | Very limited |
| Keaukaha highly decomposed plant material, 2 to 10 percent slopes | 50K | Well drained | D | Very limited | Very limited |
| Kaiwiki highly organic hydrous silty clay loam, 6 to 20 percent slopes | 48K | Well drained | C | Very limited | Very limited |
| Akaka-Kaiwiki complex, 0 to 10 percent slopes | 32K | Moderately well drained | B/D | Very limited | Very limited |
| Lava flows-Kekake complex, 2 to 20 percent slopes | 31K | Well drained | C | Very limited | Very limited |
| Kopua-Ihope complex, 3 to 10 percent slopes | 29K | Well drained | D | Very limited | Very limited |
| Hapuna-Waikui-Lalamilo complex, 0 to 20 percent slopes | 25K | Well drained | A | Very limited | Very limited |
| Opihikao highly decomposed plant material, 2 to 20 percent slopes | 23K | Well drained | D | Very limited | Very limited |
| Lava flows complex, 2 to 20 percent slopes | 23K | Excessively drained | A | Very limited | Very limited |
| Puhimau ashy silt loam, 2 to 10 percent slopes | 22K | Moderately well drained | D | Very limited | Very limited |
| Lava flows-Cinder land complex, 2 to 40 percent slopes, MLRA 161A | 21K | Excessively drained | A | Very limited | Very limited |
| Kekake-Lava flows complex, 10 to 25 percent slopes | 20K | Moderately well drained | D | Very limited | Very limited |
| Kuanene-Lava flows complex, 3 to 20 percent slopes | 20K | Well drained | D | Very limited | Very limited |
| Puna and Haplic Udarents soils, 10 to 20 percent slopes | 20K | Well drained | A | Very limited | Very limited |
| Lava flows-Kekake complex, 10 to 20 percent slopes | 20K | Well drained | C | Very limited | Very limited |
| Lava flows-Kamawai complex, 2 to 20 percent slopes | 19K | Excessively drained | A | Very limited | Very limited |
| Waiakea hydrous loam, 2 to 20 percent slopes | 19K | Well drained | C | Very limited | Very limited |
| Puu Pa very cobbly medial very fine sandy loam, 6 to 12 percent slopes | 18K | Well drained | A | Very limited | Very limited |
What This Means
Building & Foundations
About 100% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 100% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.