States / Kentucky

49 counties · median score 15

Crawl space moisture in Kentucky

Most of Kentucky drains well: only 3 of 49 counties score high or elevated, and the median is 15. Fulton County is the exception at 47; crawl-space moisture problems here usually come from grading, gutters and plumbing rather than the soil itself.

1234
  1. 1Wettest county Fulton County
  2. 2High or elevated 3 of 49
  3. 3Median score 15
  4. 4Driest county Pike County
Fulton47Henderson43Hopkins42Graves39Carter31Crittenden31Livingston31Ohio29Boone25Jefferson25Bath24Caldwell24Grayson24Carroll23Madison22
Soil moisture score (0–100) for the 15 highest of 49 counties in Kentucky, bars to scale. Score from USDA NRCS drainage class, hydrologic group, water-table depth and flooding; see methodology.
0High3Elevated12Moderate34Low
Kentucky: counties by soil moisture tier, columns to scale.

Kentucky's soil, taken as a whole

Across the 12,739,452 acres mapped in these 49 counties, 6% of soil with a drainage class is somewhat poorly, poorly or very poorly drained, and 26% 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. 49 of the 49 counties have mapped soils subject to occasional or frequent flooding.

Drainage classShare of mapped acres
Excessively drained0.1%
Somewhat excessively drained1.1%
Well drained77.1%
Moderately well drained15.5%
Somewhat poorly drained4.2%
Poorly drained1.9%
Very poorly drained0.1%

Radon. By EPA zone, 18 Kentucky counties here are zone 1 (highest potential), 29 zone 2 and 2 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 Kentucky county

Sorted wettest first. High and elevated counties link to their own page with the full soil breakdown.

Fulton County 47Henderson County 43Hopkins County 42Graves County 39Carter County 31Crittenden County 31Livingston County 31Ohio County 29Boone County 25Jefferson County 25Bath County 24Caldwell County 24Grayson County 24Carroll County 23Madison County 22Christian County 19Nelson County 19Todd County 18Washington County 18Fleming County 17Harrison County 17Marion County 16Montgomery County 16Logan County 15Mason County 15Metcalfe County 15Scott County 15Clark County 14Shelby County 14Adair County 13Elliott County 13Warren County 13Oldham County 12Barren County 11Casey County 11Fayette County 11Lewis County 10Pulaski County 9Simpson County 8Allen County 7Cumberland County 7Breathitt County 6Russell County 6Hart County 5Monroe County 5Clay County 4Clinton County 4Wayne County 4Pike County 1

What drives the Kentucky numbers

The wettest county, Fulton County, is 36% somewhat poorly drained by dominant condition, with a seasonal water table averaging 2 ft below grade across the 78% of acres that report one, and sits in EPA radon zone 3. The driest, Pike County, is 100% well drained. No Kentucky 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.