Island of Maui, Hawaii
The dominant drainage class is Well 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 Island of Maui, Hawaii.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Rough mountainous land | 54K | Well drained | B | Very limited | Very limited |
| Hydrandepts-Tropaquods association | 46K | Well drained | A | Very limited | Very limited |
| Very stony land | 34K | Well drained | A | Very limited | Very limited |
| Rock outcrop | 17K | C | Very limited | Very limited | |
| Rough broken land | 16K | Well drained | C | Very limited | Very limited |
| Rock land | 15K | Well drained | D | Very limited | Very limited |
| Waiakoa extremely stony silty clay loam, 3 to 25 percent slopes, eroded, MLRA 157 | 14K | Well drained | C | Very limited | Very limited |
| Puu Pa very stony medial silt loam, 15 to 50 percent slopes, MLRA 157 | 14K | Well drained | A | Very limited | Very limited |
| Honomanu-Amalu association | 12K | Well drained | A | Very limited | Very limited |
| Lava flows, aa | 10K | Excessively drained | A | Very limited | Very limited |
| Kamaole very stony silt loam, 3 to 15 percent slopes | 7K | Well drained | B | Somewhat limited | Very limited |
| Hana very stony silty clay loam, 3 to 25 percent slopes | 7K | Well drained | C | Somewhat limited | Very limited |
| Cinder land | 7K | Excessively drained | Very limited | Very limited | |
| Kailua silty clay, 3 to 25 percent slopes | 6K | Well drained | B | Somewhat limited | Somewhat limited |
| Oanapuka extremely stony silt loam, 7 to 25 percent slopes | 6K | Well drained | A | Very limited | Very limited |
| Amalu peat, 3 to 20 percent slopes, MLRA 164 | 5K | Poorly drained | D | Very limited | Very limited |
| Kaipoioi loam, 7 to 40 percent slopes | 5K | Well drained | B | Very limited | Very limited |
| Keawakapu extremely stony silty clay loam, 3 to 25 percent slopes, MLRA 157 | 5K | Well drained | C | Somewhat limited | Very limited |
| Stony alluvial land | 5K | Well drained | A/D | Very limited | Very limited |
| Puuone sand, 7 to 30 percent slopes | 5K | Somewhat excessively drained | A | Very limited | Very limited |
What This Means
Building & Foundations
About 91% 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 97% 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.