States / Arkansas
67 counties · median score 34
Crawl space moisture in Arkansas
Arkansas is mixed: 31 of 67 counties score high or elevated, concentrated where drainage is poorest — Poinsett County tops the list at 76 — while Izard County scores just 9. Where you are in the state matters more than the state itself.
- 1Wettest county Poinsett County
- 2High or elevated 31 of 67
- 3Median score 34
- 4Driest county Izard County
Arkansas's soil, taken as a whole
Across the 31,309,802 acres mapped in these 67 counties, 33% of soil with a drainage class is somewhat poorly, poorly or very poorly drained, and 52% of acres report a seasonal water table within about two metres. That is a wet state by any measure; a third or more of its land holds water near the surface for part of the year. 67 of the 67 counties have mapped soils subject to occasional or frequent flooding.
| Drainage class | Share of mapped acres |
|---|---|
| Excessively drained | 1% |
| Somewhat excessively drained | 2.8% |
| Well drained | 46.1% |
| Moderately well drained | 16.8% |
| Somewhat poorly drained | 10.5% |
| Poorly drained | 22.2% |
| Very poorly drained | 0.2% |
| Subaqueous | 0.4% |
Radon. By EPA zone, 0 Arkansas counties here are zone 1 (highest potential), 14 zone 2 and 53 zone 3. EPA says to test regardless of zone; a sealed crawl space is the cheapest moment to add radon venting if a test calls for it.
Every Arkansas county
Sorted wettest first. High and elevated counties link to their own page with the full soil breakdown.
What drives the Arkansas numbers
The wettest county, Poinsett County, is 66% poorly drained by dominant condition, with a seasonal water table averaging 0.9 ft below grade across the 94% of acres that report one, and sits in EPA radon zone 3. The driest, Izard County, is 93% well drained. 17 Arkansas counties reach the high tier, where poorly drained soils, group D clays and a shallow water table occur together.
The score is a guide to the soil, not to a house: a well-graded lot with working gutters in a high county can have a dry crawl space, and a bad downspout can flood one in a low county. The R408 calculator sizes venting or encapsulation for any footprint.
Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted; EPA Map of Radon Zones, county table (June 2024 JSON). Checked 2026-10-23.