📍
State soils

Hawaii Soil Surveys

8 survey areas
The short version

The most common soil here is Rough mountainous land, on about 5% of the land. Rough broken land and Kaiwiki come next.

About 85% of the land drains well, and 2% stays wet for long stretches; groundwater comes within two feet of the surface under 6% of it.

USDA rates 94% of the land very limited for a standard septic drain field, and 86% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 4% of the land floods occasionally or more, and bedrock lies within 40 inches under 60% 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 ground underfoot

The soils you're most likely standing on

The biggest named soils in Hawaii, each drawn five feet deep from its official USDA description, in its recorded colors.

Kaiwiki
2% of the area
Hydrous silty clay loam topsoil · well drained
Smooth and slightly sticky. Holds a lot of water.
Andisols
Keei
1% of the area
Well drained
Histosols
Honokaa
1% of the area
Hydrous silty clay loam topsoil · well drained
Smooth and slightly sticky. Holds a lot of water.
Andisols

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.

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

Look Up a Specific Address

📍