Island of Lanai, Hawaii
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate 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 Lanai, Hawaii.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Very stony land, eroded | 17K | Well drained | C | Very limited | Very limited |
| Very stony land | 16K | Well drained | D | Very limited | Very limited |
| Rock land | 8K | Well drained | D | Very limited | Very limited |
| Koele-Badland complex, 7 to 70 percent slopes, MLRA 158 | 6K | Well drained | A | Very limited | Very limited |
| Rock outcrop | 6K | C | Very limited | Very limited | |
| Molokai silty clay loam, 3 to 7 percent slopes, MLRA 158 | 4K | Well drained | C | Not limited | Very limited |
| Blown-out land | 3K | Well drained | C | Somewhat limited | Very limited |
| Rough mountainous land | 3K | Well drained | B | Very limited | Very limited |
| Mala silty clay, 0 to 3 percent slopes, MLRA 163 | 2K | Well drained | B | Very limited | Very limited |
| Waihuna clay, 0 to 3 percent slopes, MLRA 158 | 2K | Well drained | C | Very limited | Very limited |
| Molokai silty clay loam, 0 to 3 percent slopes, MLRA 158 | 2K | Well drained | C | Not limited | Very limited |
| Uwala silty clay loam, 2 to 7 percent slopes, MLRA 158 | 2K | Well drained | B | Not limited | Somewhat limited |
| Stony blown-out land | 1K | Well drained | C | Very limited | Very limited |
| Lahaina silty clay, 3 to 7 percent slopes, MLRA 158 | 1K | Well drained | B | Not limited | Somewhat limited |
| Molokai silty clay loam, 7 to 15 percent slopes, severely eroded, MLRA 158 | 1K | Well drained | C | Somewhat limited | Very limited |
| Waihuna clay, 3 to 7 percent slopes, MLRA 158 | 1K | Well drained | C | Very limited | Very limited |
| Uwala silty clay loam, 7 to 15 percent slopes, MLRA 158 | 1K | Well drained | B | Somewhat limited | Somewhat limited |
| Uwala silty clay loam, 7 to 15 percent slopes, severely eroded, MLRA 158 | 1K | Well drained | B | Somewhat limited | Somewhat limited |
| Rough broken land | 986 | Well drained | C | Very limited | Very limited |
| Koele silty clay loam, 7 to 15 percent slopes, MLRA 158 | 986 | Well drained | A | Very limited | Very limited |
What This Means
Building & Foundations
About 81% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 93% 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.