Hawaii Soil Surveys
Hawaii has 8 USDA soil survey areas covering a wide range of landscapes and soil conditions. The most common soil order is Andisols — soils formed in volcanic ash, very light and porous, making up roughly 41% of surveyed soils. Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter account for another 13%.
In terms of drainage, 74% of Hawaii soils are classified as well drained. Drainage class affects everything from septic system design to basement feasibility to garden planning. Use the survey area pages below to see drainage details for specific counties, or look up any address for an exact soil profile.
Soil Types
Andisols
41% of surveyed soils
Volcanic ash soils — light, porous, and fertile. Excellent drainage, but low density can complicate foundations.
Mollisols
13% of surveyed soils
Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.
Oxisols
11% of surveyed soils
Deeply weathered tropical soils. Nutrient-poor despite appearing lush. Rare in the continental US.
Ultisols
7% of surveyed soils
Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.
Entisols
6% of surveyed soils
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.
Histosols
6% of surveyed soils
Organic peat and muck soils formed in wetlands. Very poor for building (compressible) and septic. Often in regulated wetlands.
Inceptisols
6% of surveyed soils
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.
Vertisols
3% of surveyed soils
High-clay soils that shrink and swell dramatically. Fertile but challenging for foundations and septic systems.
Aridisols
2% of surveyed soils
Dry-climate soils with low organic matter. Often have caliche layers that make excavation difficult. Low shrink-swell is good for foundations.
Survey Areas
Hawaii Volcanoes National Park, HawaiiIsland of Hawaii Area, HawaiiIsland of Kahoolawe, HawaiiIsland of Kauai, HawaiiIsland of Lanai, HawaiiIsland of Maui, HawaiiIsland of Molokai, HawaiiIsland of Oahu, Hawaii