Island of Hawaii Area, Hawaii
The most common soil here is Kaiwiki, on about 3% of the land: a hydrous silty clay loam, smooth and slightly sticky. Keei and Honokaa come next.
About 84% of the land drains well; groundwater comes within two feet of the surface under 7% of it.
USDA rates 96% of the land very limited for a standard septic drain field, and 91% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 5% of the land floods occasionally or more, and bedrock lies within 40 inches under 66% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Island of Hawaii Area, Hawaii, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low runoff). The most common soil order is Andisols — soils formed in volcanic ash, very light and porous. 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. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| 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 |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 91% 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 96% 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.