Island of Kahoolawe, Hawaii
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). 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 Kahoolawe, Hawaii.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Typic Torriorthents, badlands-Typic Haplotorrox-Rock outcrop complex,10 to 30 percent slopes | 5K | Well drained | B | Very limited | Very limited |
| Lithic Torriorthents-Rock outcrop complex, 5 to 15 percent slopes | 5K | Well drained | D | Somewhat limited | Somewhat limited |
| Typic Haplocambids, moderately deep-Rock outcrop complex, 5 to 20 percent slopes | 3K | Well drained | C | Very limited | Very limited |
| Lithic Torriorthents-Rock outcrop complex, 15 to 30 percent slopes | 2K | Well drained | D | Very limited | Very limited |
| Typic Haplotorrox, wind polished, 3 to12 percent slopes | 2K | Well drained | B | Not limited | Somewhat limited |
| Rock outcrop-Lithic Torriorthents complex, 30 to 50 percent slopes | 2K | C | Very limited | Very limited | |
| Rock outcrop-Lithic Torriorthents complex, 50 to 150 percent slopes | 1K | C | Very limited | Very limited | |
| Typic Haplocambids, deep, 3 to 12 percent slopes | 1K | Well drained | B | Somewhat limited | Somewhat limited |
| Typic Haplotorrox, wind polished, 12 to 20 percent slopes | 973 | Well drained | B | Very limited | Very limited |
| Typic Torriorthents, saprolite-Rock outcrop complex, 5 to 20 percent slopes | 707 | Well drained | B | Somewhat limited | Somewhat limited |
| Typic Haplotorrox, windblown, 3 to 12 percent slopes | 697 | Well drained | B | Not limited | Somewhat limited |
| Typic Haplocambids, moderately deep, 3 to 12 percent slopes | 621 | Well drained | C | Very limited | Very limited |
| Typic Haplotorrox, wind polished-Typic Torriorthents, badlands, complex, 3 to 12 percent slopes | 479 | Well drained | B | Not limited | Somewhat limited |
| Typic Haplotorrox, windblown, 8 to 20 percent slopes | 446 | Well drained | B | Somewhat limited | Somewhat limited |
| Typic Torriorthents, badlands-Typic Torriorthents, eolian, complex,5 to 25 percent slopes | 436 | Well drained | B | Very limited | Very limited |
| Typic Haplotorrox, 5 to 15 percent slopes | 357 | Well drained | B | Somewhat limited | Somewhat limited |
| Typic Haplotorrox, windblown, 3 to 8 percent slopes, hummocky | 336 | Well drained | C | Somewhat limited | Very limited |
| Rock outcrop-Typic Haplocambid, moderately deep, complex, 12 to 25 percent slopes | 259 | C | Very limited | Very limited | |
| Typic Haplocambids, deep-Typic Haplocambids, moderately deep complex, 3 to 8 percent slopes | 234 | Well drained | B | Somewhat limited | Somewhat limited |
| Typic Haplotorrox, black subsoil, 8 to 20 percent slopes, gullied | 224 | Well drained | C | Somewhat limited | Very limited |
What This Means
Building & Foundations
About 58% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes. A geotechnical assessment is recommended before building.
Septic Systems
About 60% 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.