Gallia County, Ohio
A shallow water table limits basements on 26% of Gallia County's mapped land. Shrink-swell clay limits houses without basements on 29%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 8 flood losses here since 2016. 48% of homes were built before 1980, against 50% nationally; the median home dates from 1981.
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 Gallia County
| Expansive clay (limits slab homes) | 29.1% |
| High water table (limits basements) | 25.9% |
| Septic fields very limited | 91.6% |
| Clay swell (LEP, by area) | 3.7% |
| High-swell land (LEP 6%+) | 28.9% |
| Mapped soil | 301,498 acres |
How we count · survey areas OH053 (2025-08-27)
What the numbers mean here
Clay swell averages a linear extensibility of 3.7% by land area here, and 29% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 29% of the mapped land.
On 26% of Gallia 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: 42.65 in, 1.14 in below the 1991-2020 average year of 43.79 in.
USDA rates 92% of the land very limited for septic absorption fields.
Drought
0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 5 of the last 52 weeks; the most was 100% of its area, on the May 19, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
8 flood losses since 2016, $64,107 paid. The worst year was 2025, with 2.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 2 |
| 2019 | 1 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 2 |
| 2024 | 1 |
| 2025 | 2 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 43.79 in |
| 12 months to August 2026 | 42.65 in (-1.14) |
| 2025 | 47.19 in (+3.40) |
| Wettest year since 1895 | 2011: 57.88 in |
| Driest year since 1895 | 1930: 24.60 in |
| Days with 1 inch or more, normal at GALLIPOLIS (6 mi away) | 9.8 |
Homes
| Housing units | 13,464 |
| Median year built | 1981 |
| Built before 1980 | 48% |
| Built 2000 or later | 23% |
| Owner-occupied | 75% |
| Median value, owner-occupied | $155,600 |
| Single-family detached | 69% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Gallia County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Centerville (Thurman) | 1% | 79% | 19 |
| Cheshire | 7% | 25% | 67 |
| Crown City | 19% | 21% | 229 |
| Gallipolis | 15% | 33% | 1,848 |
| Rio Grande | 21% | 54% | 307 |
| Vinton | 10% | 41% | 134 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Mason County, WV | 15 mi | 32% | 16% |
| Lawrence County, OH | 19 mi | 29% | 11% |
| Jackson County, OH | 22 mi | 17% | 53% |
| Meigs County, OH | 24 mi | 43% | 21% |
| Cabell County, WV | 28 mi | 21% | 11% |
| Putnam County, WV | 30 mi | 33% | 9% |
| Vinton County, OH | 32 mi | 12% | 37% |
| Jackson County, WV | 34 mi | 47% | 9% |
Sources: USDA SSURGO (August 27, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status