States / North Carolina
100 counties · median score 17
Crawl space moisture in North Carolina
North Carolina is mixed: 31 of 100 counties score high or elevated, concentrated where drainage is poorest — Currituck County tops the list at 75 — while Yancey County scores just 2. Where you are in the state matters more than the state itself.
- 1Wettest county Currituck County
- 2High or elevated 31 of 100
- 3Median score 17
- 4Driest county Yancey County
North Carolina's soil, taken as a whole
Across the 33,683,830 acres mapped in these 100 counties, 30% of soil with a drainage class is somewhat poorly, poorly or very poorly drained, and 46% 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. 100 of the 100 counties have mapped soils subject to occasional or frequent flooding.
| Drainage class | Share of mapped acres |
|---|---|
| Excessively drained | 1% |
| Somewhat excessively drained | 3% |
| Well drained | 55.4% |
| Moderately well drained | 10.9% |
| Somewhat poorly drained | 5.5% |
| Poorly drained | 12.3% |
| Very poorly drained | 11.3% |
| Subaqueous | 0.5% |
Radon. By EPA zone, 8 North Carolina counties here are zone 1 (highest potential), 31 zone 2 and 61 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 North Carolina county
Sorted wettest first. High and elevated counties link to their own page with the full soil breakdown.
What drives the North Carolina numbers
The wettest county, Currituck County, is 36% subaqueous by dominant condition, with a seasonal water table averaging 0.3 ft below grade across the 73% of acres that report one, and sits in EPA radon zone 3. The driest, Yancey County, is 82% well drained. 16 North Carolina 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.