Union County, Arkansas
A shallow water table limits basements on 74% of Union County's mapped land, a higher share than 84% of US counties. Shrink-swell clay limits houses without basements on 15%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 17 flood losses here since 2016. 51% of homes were built before 1980, against 50% nationally; the median home dates from 1979.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Union County
| Expansive clay (limits slab homes) | 14.6% |
| High water table (limits basements) | 74.2% |
| Septic fields very limited | 81.0% |
| Clay swell (LEP, by area) | 3.3% |
| High-swell land (LEP 6%+) | 14.6% |
| Mapped soil | 675,693 acres |
How we count · survey areas AR139 (2025-09-10)
What the numbers mean here
On 74% of Union County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 36.38 in, 18.71 in below the 1991-2020 average year of 55.09 in.
USDA rates 81% of the land very limited for septic absorption fields.
Drought
100% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 43 of the last 52 weeks; the most was 100% of its area, in 34 weeks, most recently on the October 13, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 100% |
| D2 severe or worse | 100% |
| D3 extreme or worse | 100% |
| D4 exceptional | 69.8% |
Flood losses since 2016
17 flood losses since 2016, $840,790 paid. The worst year was 2022, with 5.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 1 |
| 2018 | 3 |
| 2019 | 2 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 5 |
| 2023 | 1 |
| 2024 | 3 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 55.09 in |
| 12 months to August 2026 | 36.38 in (-18.71) |
| 2025 | 52.02 in (-3.07) |
| Wettest year since 1895 | 2009: 76.61 in |
| Driest year since 1895 | 2005: 33.53 in |
| Days with 1 inch or more, normal at CALION L&D (12 mi away) | 16.2 |
Homes
| Housing units | 18,649 |
| Median year built | 1979 |
| Built before 1980 | 51% |
| Built 2000 or later | 23% |
| Owner-occupied | 73% |
| Median value, owner-occupied | $120,900 |
| Single-family detached | 72% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Union Parish, LA | 27 mi | 10% | 48% |
| Calhoun County, AR | 28 mi | 3% | 83% |
| Bradley County, AR | 32 mi | 6% | 79% |
| Claiborne Parish, LA | 33 mi | 22% | 28% |
| Ouachita County, AR | 33 mi | 9% | 45% |
| Columbia County, AR | 37 mi | 23% | 81% |
| Lincoln Parish, LA | 39 mi | 8% | 36% |
| Ashley County, AR | 48 mi | 11% | 80% |
Sources: USDA SSURGO (September 10, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status