States / Kansas
105 counties · median score 13
Crawl space moisture in Kansas
Kansas is mixed: 23 of 105 counties score high or elevated, concentrated where drainage is poorest — Crawford County tops the list at 59 — while Stevens County scores just 1. Where you are in the state matters more than the state itself.
- 1Wettest county Crawford County
- 2High or elevated 23 of 105
- 3Median score 13
- 4Driest county Stevens County
Kansas's soil, taken as a whole
Across the 52,657,481 acres mapped in these 105 counties, 8% of soil with a drainage class is somewhat poorly, poorly or very poorly drained, and 19% of acres report a seasonal water table within about two metres. That is a dry figure; wet soils here are confined to river bottoms and wetlands. 105 of the 105 counties have mapped soils subject to occasional or frequent flooding.
| Drainage class | Share of mapped acres |
|---|---|
| Excessively drained | 1.5% |
| Somewhat excessively drained | 3% |
| Well drained | 69.1% |
| Moderately well drained | 18.2% |
| Somewhat poorly drained | 7.1% |
| Poorly drained | 1.1% |
Radon. By EPA zone, 65 Kansas counties here are zone 1 (highest potential), 40 zone 2 and 0 zone 3. With most of the state in zone 1, any crawl-space sealing project here should start with a radon test and be designed to take a radon fan.
Every Kansas county
Sorted wettest first. High and elevated counties link to their own page with the full soil breakdown.
What drives the Kansas numbers
The wettest county, Crawford County, is 73% somewhat poorly drained by dominant condition, with a seasonal water table averaging 1.4 ft below grade across the 80% of acres that report one, and sits in EPA radon zone 2. The driest, Stevens County, is 84% well drained. No Kansas county reaches the high tier.
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.