Island of Molokai, Hawaii
The most common soil here is Rough mountainous land, on about 20% of the land. Very stony land, eroded and Molokai come next.
About 89% of the land drains well, and 5% stays wet for long stretches; groundwater comes within two feet of the surface under 4% of it.
USDA rates 88% of the land very limited for a standard septic drain field, and 65% 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 51% 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 Molokai, 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 C (slow infiltration, moderate runoff). The most common soil order is Oxisols — highly weathered tropical soils, deep but nutrient-poor. 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 Molokai, 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 |
|---|---|---|---|---|---|
| Rough mountainous land | 34K | Well drained | B | Very limited | Very limited |
| Very stony land, eroded | 16K | Well drained | C | Very limited | Very limited |
| Rough broken land | 9K | Well drained | C | Not rated | Not rated |
| Very stony land | 9K | Well drained | D | Very limited | Very limited |
| Rock land | 9K | Well drained | D | Very limited | Very limited |
| Rock outcrop | 7K | C | Very limited | Very limited | |
| Molokai silty clay loam, 3 to 7 percent slopes, MLRA 158 | 7K | Well drained | C | Not limited | Very limited |
| Tropaquods | 4K | Poorly drained | D | Very limited | Very limited |
| Hoolehua silty clay, 7 to 15 percent slopes | 4K | Well drained | C | Somewhat limited | Very limited |
| Molokai silty clay loam, 7 to 15 percent slopes, MLRA 158 | 3K | Well drained | C | Somewhat limited | Very limited |
| Holomua silt loam, 3 to 7 percent slopes | 2K | Well drained | C | Not limited | Very limited |
| Oli medial silt loam, 10 to 30 percent slopes, MLRA 165 | 2K | Well drained | B | Very limited | Very limited |
| Colluvial land | 2K | Well drained | B | Very limited | Very limited |
| Gullied land | 2K | Well drained | Very limited | Very limited | |
| Water | 2K | D | Not rated | Not rated | |
| Lahaina silty clay, 3 to 7 percent slopes, MLRA 158 | 2K | Well drained | B | Not limited | Somewhat limited |
| Mala silty clay, 0 to 3 percent slopes, MLRA 166 | 2K | Well drained | B | Very limited | Very limited |
| Molokai silty clay loam, 0 to 3 percent slopes, MLRA 158 | 2K | Well drained | C | Not limited | Very limited |
| Hoolehua silty clay, 3 to 7 percent slopes | 2K | Well drained | C | Not limited | Very limited |
| Kahanui gravelly silty clay, 3 to 20 percent slopes | 2K | Well drained | C | Somewhat 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 65% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 88% 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.