Hawaii: basement moisture and foundation risk by county
5 counties, ranked by our combined index. Highest combined risk is Honolulu County (50), lowest is Hawaii County (36). The worst soil for foundation cracks specifically is in Honolulu County.
| County | Index | Moisture | Cracks | Water table | Region |
|---|---|---|---|---|---|
| Honolulu County | 50 | 35 | 75 | 46 | Hawaiian volcanic soils |
| Maui County | 46 | 36 | 60 | 46 | Hawaiian volcanic soils |
| Kauai County | 45 | 36 | 56 | 46 | Hawaiian volcanic soils |
| Kalawao County | 40 | 33 | 44 | 46 | Hawaiian volcanic soils |
| Hawaii County | 36 | 33 | 45 | 30 | Hawaiian volcanic soils |
Values from USDA NRCS SSURGO where available, otherwise our regional model — each county page states which. Methodology.
The physiographic regions inside Hawaii
State lines are political; soil follows geology. These are the distinct ground types inside Hawaii and why each behaves the way it does.
Hawaiian volcanic soils
Volcanic soils behave unlike anything on the mainland: some hold enormous water yet drain well, while leeward Vertisols are strongly expansive. Basements are essentially absent; the moisture problem is post-and-pier crawlspaces and slab-on-grade in a climate that never dries out.
5 counties: Hawaii County, Honolulu County, Kalawao County, Kauai County, Maui County
Page data updated