Marshall County, Tennessee
Shrink-swell clay limits houses without basements on 21% of Marshall County's mapped land, a higher share than 71% of US counties and the 8th highest of 95 Tennessee counties. A shallow water table limits basements on 10%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 6 flood losses here since 2016. 38% of homes were built before 1980, against 50% nationally; the median home dates from 1991.
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 Marshall County
| Expansive clay (limits slab homes) | 21.1% |
| High water table (limits basements) | 10.3% |
| Septic fields very limited | 80.3% |
| Clay swell (LEP, by area) | 4.9% |
| High-swell land (LEP 6%+) | 24.0% |
| Urban land, not rated | 1.0% |
| Mapped soil | 241,000 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Talbott | 18% | n/a |
| Mimosa | 9% | n/a |
| Hawthorne | 7% | n/a |
| Braxton | 7% | n/a |
| Dellrose | 5% | n/a |
| Ashwood | 5% | n/a |
How we count · survey areas TN117 (2025-08-29)
What the numbers mean here
Clay swell averages a linear extensibility of 4.9% by land area here, and 24% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 21% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 21% of Marshall County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 53.58 in, 2.58 in below the 1991-2020 average year of 56.16 in.
USDA rates 80% 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 28 of the last 52 weeks; the most was 100% of its area, in 17 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 | 30.9% |
| D4 exceptional | 0% |
Flood losses since 2016
6 flood losses since 2016, $32,677 paid. The worst year was 2025, with 2.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 1 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 1 |
| 2021 | 0 |
| 2022 | 2 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 2 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 56.16 in |
| 12 months to August 2026 | 53.58 in (-2.58) |
| 2025 | 55.62 in (-0.54) |
| Wettest year since 1895 | 1989: 72.87 in |
| Driest year since 1895 | 2007: 36.15 in |
| Days with 1 inch or more, normal at LEWISBURG EXP STN (4 mi away) | 16.3 |
Homes
| Housing units | 14,749 |
| Median year built | 1991 |
| Built before 1980 | 38% |
| Built 2000 or later | 32% |
| Owner-occupied | 77% |
| Median value, owner-occupied | $279,800 |
| Single-family detached | 83% |
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 |
|---|---|---|---|
| Bedford County, TN | 18 mi | 33% | 23% |
| Maury County, TN | 20 mi | 8% | 9% |
| Giles County, TN | 24 mi | 11% | 20% |
| Lincoln County, TN | 24 mi | 28% | 28% |
| Moore County, TN | 26 mi | 22% | 15% |
| Williamson County, TN | 31 mi | 8% | 17% |
| Rutherford County, TN | 32 mi | 21% | 14% |
| Coffee County, TN | 39 mi | 2% | 45% |
Sources: USDA SSURGO (August 29, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status