Hawaii Volcanoes National Park, Hawaii
The dominant drainage class is Excessively 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 Hawaii Volcanoes National Park, Hawaii.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Lava flows, `a`a, 2 to 20 percent slopes | 111K | Excessively drained | A | Very limited | Very limited |
| Lava flows, pahoehoe, 2 to 20 percent slopes | 77K | C | Very limited | Very limited | |
| Lava flows complex, 2 to 20 percent slopes | 32K | Excessively drained | A | Very limited | Very limited |
| Lava flows-Lithic Ustipsamments complex, 2 to 10 percent slopes | 19K | Somewhat excessively drained | C | Very limited | Very limited |
| Kanohina-Lava flows complex, 2 to 10 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Nakanui-Lava flows complex, 2 to 10 percent slopes | 9K | Well drained | D | Very limited | Very limited |
| Lithic Haplustands-Lava flows complex, 2 to 10 percent slopes | 8K | Well drained | D | Very limited | Very limited |
| Lava flows-Apuki complex, 2 to 20 percent slopes | 7K | Somewhat excessively drained | C | Very limited | Very limited |
| Makaopuhi very paragravelly highly decomposed plant material, 2 to 10 percent slopes | 6K | Somewhat poorly drained | D | Very limited | Very limited |
| Puaulu-Hao complex, 2 to 20 percent slopes | 5K | Moderately well drained | D | Not limited | Very limited |
| Kalapana-Lava flows complex, dry, 2 to 10 percent slopes | 5K | Well drained | D | Very limited | Very limited |
| Puhimau ashy silt loam, 2 to 10 percent slopes | 4K | Moderately well drained | D | Very limited | Very limited |
| Ahiu-Lava flows complex, 2 to 10 percent slopes | 4K | Well drained | D | Very limited | Very limited |
| Alahapa-Lava flows complex, 2 to 10 percent slopes | 3K | Somewhat excessively drained | A | Very limited | Very limited |
| Ihuanu-Lava flows, `a`a complex, 10 to 20 percent slopes, MLRA 160 | 3K | Well drained | A | Very limited | Very limited |
| Iwalani-Lava flows complex, 10 to 20 percent slopes | 3K | Well drained | D | Very limited | Very limited |
| Kalapana medial coarse sandy loam, 2 to 10 percent slopes | 3K | Well drained | D | Very limited | Very limited |
| Lava flows association, 40 to 99 percent slopes | 3K | Excessively drained | A | Very limited | Very limited |
| Lava flows-Iwalani complex, 10 to 20 percent slopes | 2K | Well drained | C | Very limited | Very limited |
| Kilauea very gravelly ashy sand, 2 to 10 percent slopes | 2K | Excessively drained | D | Not limited | Very limited |
What This Means
Building & Foundations
About 97% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, sandy or gravelly soils with low bearing capacity. A geotechnical assessment is recommended before building.
Septic Systems
About 100% of soils are rated "very limited" for septic absorption fields. The well-drained soils may actually drain too fast for standard leach fields, allowing effluent to reach groundwater. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Soils tend to drain very quickly, meaning nutrients and water don't stick around long. Raised beds with amended soil, drip irrigation, and heavy mulching will give the best results. Compost is your best friend here — it improves water retention dramatically.