Clark County, Ohio
A shallow water table limits basements on 59% of Clark County's mapped land, a higher share than 73% of US counties. Shrink-swell clay limits houses without basements on 17%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 35 flood losses here since 2016, 13% of them in buildings with basements. 77% of homes were built before 1980, against 50% nationally; the median home dates from 1963.
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 Clark County
| Expansive clay (limits slab homes) | 17.3% |
| High water table (limits basements) | 58.8% |
| Septic fields very limited | 77.9% |
| Clay swell (LEP, by area) | 4.5% |
| High-swell land (LEP 6%+) | 0.5% |
| Urban land, not rated | 1.4% |
| Mapped soil | 256,883 acres |
How we count · survey areas OH023 (2025-08-27)
What the numbers mean here
Clay swell averages a linear extensibility of 4.5% by land area here, and under 1% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 17% of the mapped land.
On 59% of Clark 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: 46.69 in, 4.41 in above the 1991-2020 average year of 42.28 in.
USDA rates 78% 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 1 of the last 52 weeks; the most was 3.9% of its area, on the October 21, 2025 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
35 flood losses since 2016, $1.3 million paid. The worst year was 2017, with 14. Foundations of the buildings, where recorded: 13% basements, 39% slabs, 43% crawl spaces, 4% elevated. Median water depth outside the building: 9 in.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 14 |
| 2018 | 3 |
| 2019 | 3 |
| 2020 | 5 |
| 2021 | 0 |
| 2022 | 3 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 7 |
Rain
| Average year, 1991-2020 | 42.28 in |
| 12 months to August 2026 | 46.69 in (+4.41) |
| 2025 | 42.71 in (+0.43) |
| Wettest year since 1895 | 2011: 58.30 in |
| Driest year since 1895 | 1934: 24.74 in |
| Days with 1 inch or more, normal at SPRINGFIELD WTP (4 mi away) | 9.1 |
Homes
| Housing units | 61,126 |
| Median year built | 1963 |
| Built before 1980 | 77% |
| Built 2000 or later | 9% |
| Owner-occupied | 69% |
| Median value, owner-occupied | $169,900 |
| Single-family detached | 75% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Clark County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Catawba | 9% | 10% | 126 |
| Donnelsville | 3% | 74% | 122 |
| Enon | 8% | 39% | 1,130 |
| New Carlisle | 44% | 32% | 2,168 |
| North Hampton | 11% | 77% | 142 |
| South Charleston | 11% | 63% | 904 |
| South Vienna | 30% | 69% | 225 |
| Springfield | 6% | 31% | 27,758 |
| Tremont City | 4% | 53% | 148 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Champaign County, OH | 16 mi | 13% | 83% |
| Greene County, OH | 17 mi | 8% | 68% |
| Madison County, OH | 20 mi | 36% | 94% |
| Miami County, OH | 25 mi | 18% | 81% |
| Montgomery County, OH | 29 mi | 17% | 65% |
| Fayette County, OH | 30 mi | 37% | 96% |
| Logan County, OH | 32 mi | 26% | 81% |
| Clinton County, OH | 34 mi | 16% | 93% |
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