Island of Kauai, Hawaii
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate 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 Kauai, Hawaii.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Rough mountainous land | 68K | Well drained | B | Very limited | Very limited |
| Rough broken land | 50K | Well drained | C | Very limited | Very limited |
| Rock outcrop | 42K | C | Very limited | Very limited | |
| Lihue silty clay, 0 to 8 percent slopes | 9K | Well drained | C | Not limited | Very limited |
| Waiawa-Rock outcrop complex, 30 to 80 percent slopes, MLRA 158 | 9K | Well drained | D | Very limited | Very limited |
| Hihimanu silty clay loam, 40 to 70 percent slopes | 8K | Well drained | B | Very limited | Very limited |
| Puhi silty clay loam, 3 to 8 percent slopes | 8K | Well drained | B | Not limited | Somewhat limited |
| Alakai mucky peat, 0 to 30 percent slopes, MLRA 164 | 6K | Very poorly drained | C/D | Very limited | Very limited |
| Kapaa silty clay, 3 to 8 percent slopes | 6K | Well drained | B | Not limited | Somewhat limited |
| Waialeale mucky silty clay loam, 30 to 70 percent slopes | 4K | Poorly drained | B/D | Very limited | Very limited |
| Kalapa silty clay, 40 to 70 percent slopes | 4K | Well drained | C | Very limited | Very limited |
| Water > 40 acres | 4K | D | Not rated | Not rated | |
| Jaucas loamy fine sand, 0 to 8 percent slopes | 4K | Excessively drained | A | Very limited | Very limited |
| Makaweli silty clay loam, 0 to 6 percent slopes, MLRA 158 | 4K | Well drained | C | Not limited | Very limited |
| Makaweli silty clay loam, 6 to 12 percent slopes, MLRA 158 | 4K | Well drained | C | Somewhat limited | Very limited |
| Badland-Mahana complex | 3K | Well drained | Very limited | Very limited | |
| Kokee silty clay loam, 35 to 70 percent slopes | 3K | Well drained | A | Very limited | Very limited |
| Oli medial silt loam, 30 to 70 percent slopes, MLRA 165 | 3K | Well drained | B | Very limited | Very limited |
| Hulua gravelly silty clay loam, 25 to 70 percent slopes | 3K | Poorly drained | D | Very limited | Very limited |
| Hanamaulu silty clay, 3 to 8 percent slopes | 3K | Well drained | B | Somewhat limited | Somewhat limited |
What This Means
Building & Foundations
About 85% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 91% 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.