Sumner County, Tennessee
A shallow water table limits basements on 19% of Sumner County's mapped land. Shrink-swell clay limits houses without basements on 18%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 179 flood losses here since 2016, 5% of them in buildings with basements. 31% of homes were built before 1980, against 50% nationally; the median home dates from 1995.
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 Sumner County
| Expansive clay (limits slab homes) | 17.7% |
| High water table (limits basements) | 18.6% |
| Septic fields very limited | 73.3% |
| Clay swell (LEP, by area) | 3.5% |
| High-swell land (LEP 6%+) | 18.5% |
| Urban land, not rated | 1.3% |
| Mapped soil | 348,100 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Mimosa | 14% | n/a |
| Sulphura | 12% | n/a |
| Harpeth | 12% | n/a |
| Sugargrove | 9% | n/a |
| Dickson | 7% | n/a |
| Sengtown | 6% | n/a |
How we count · survey areas TN165 (2025-08-29)
What the numbers mean here
Clay swell averages a linear extensibility of 3.5% by land area here, and 19% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 18% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 18% of Sumner County's mapped land has shrink-swell clay.
On 19% of Sumner 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: 41.19 in, 11.73 in below the 1991-2020 average year of 52.92 in.
USDA rates 73% 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 23 of the last 52 weeks; the most was 100% of its area, in 18 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 | 18.5% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
179 flood losses since 2016, $4.4 million paid. The worst year was 2024, with 49. Foundations of the buildings, where recorded: 5% basements, 21% slabs, 63% crawl spaces, 11% elevated. Median water depth outside the building: 16 in.
| Year | Flood losses |
|---|---|
| 2016 | 49 |
| 2017 | 26 |
| 2018 | 2 |
| 2019 | 29 |
| 2020 | 8 |
| 2021 | 7 |
| 2022 | 1 |
| 2023 | 2 |
| 2024 | 49 |
| 2025 | 4 |
| 2026 to date | 2 |
Rain
| Average year, 1991-2020 | 52.92 in |
| 12 months to August 2026 | 41.19 in (-11.73) |
| 2025 | 57.43 in (+4.51) |
| Wettest year since 1895 | 1979: 71.31 in |
| Driest year since 1895 | 1930: 33.94 in |
| Days with 1 inch or more, normal at BETHPAGE 1 S (7 mi away) | 16.1 |
Homes
| Housing units | 83,236 |
| Median year built | 1995 |
| Built before 1980 | 31% |
| Built 2000 or later | 43% |
| Owner-occupied | 72% |
| Median value, owner-occupied | $393,100 |
| Single-family detached | 73% |
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 |
|---|---|---|---|
| Trousdale County, TN | 17 mi | 44% | 10% |
| Simpson County, KY | 21 mi | 1% | 11% |
| Wilson County, TN | 23 mi | 16% | 14% |
| Robertson County, TN | 24 mi | 0% | 32% |
| Allen County, KY | 25 mi | 0% | 12% |
| Macon County, TN | 26 mi | 10% | 16% |
| Davidson County, TN | 27 mi | 14% | 8% |
| Smith County, TN | 31 mi | 41% | 3% |
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