Unicoi County, Tennessee
USDA's soil survey flags shrink-swell clay on 0% of Unicoi County's mapped land and a shallow water table under basements on 1%, both below the national shares of 15% and 29%. None of the county is in drought on the October 13, 2026 Drought Monitor map.
FEMA's flood data list 29 flood losses here since 2016, 11% of them in buildings with basements. 57% of homes were built before 1980, against 50% nationally; the median home dates from 1977.
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 Unicoi County
| Expansive clay (limits slab homes) | 0.0% |
| High water table (limits basements) | 1.3% |
| Septic fields very limited | 92.5% |
| Clay swell (LEP, by area) | 1.4% |
| High-swell land (LEP 6%+) | 0.0% |
| Mapped soil | 119,300 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Ditney | 19% | n/a |
| Ashe | 13% | n/a |
| Tate | 8% | n/a |
| Soco | 7% | n/a |
| Unicoi | 5% | n/a |
| Northcove | 5% | n/a |
How we count · survey areas TN171 (2025-08-29)
What the numbers mean here
Rain over the 12 months to August 2026: 45.03 in, 6.10 in below the 1991-2020 average year of 51.13 in.
USDA rates 93% of the land very limited for septic absorption fields.
With shrink-swell clay on 0% and a shallow water table on 1% of the land, the soil survey points to neither problem across most of Unicoi County; conditions still vary lot by lot.
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 36 of the last 52 weeks; the most was 100% of its area, in 25 weeks, most recently on the June 23, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
29 flood losses since 2016, $1.1 million paid. The worst year was 2024, with 17. Foundations of the buildings, where recorded: 11% basements, 22% slabs, 59% crawl spaces, 7% elevated. Median water depth outside the building: 13 in.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 2 |
| 2019 | 2 |
| 2020 | 6 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 17 |
| 2025 | 0 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 51.13 in |
| 12 months to August 2026 | 45.03 in (-6.10) |
| 2025 | 45.49 in (-5.64) |
| Wettest year since 1895 | 2020: 65.17 in |
| Driest year since 1895 | 1925: 33.74 in |
| Days with 1 inch or more, normal at ERWIN 1 W (3 mi away) | 10.3 |
Homes
| Housing units | 8,749 |
| Median year built | 1977 |
| Built before 1980 | 57% |
| Built 2000 or later | 15% |
| Owner-occupied | 73% |
| Median value, owner-occupied | $189,600 |
| Single-family detached | 67% |
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 |
|---|---|---|---|
| Washington County, TN | 14 mi | 1% | 10% |
| Mitchell County, NC | 15 mi | under 1% | 2% |
| Yancey County, NC | 16 mi | 0% | 3% |
| Carter County, TN | 21 mi | 1% | 1% |
| Madison County, NC | 23 mi | 0% | 2% |
| Greene County, TN | 25 mi | 2% | 20% |
| Avery County, NC | 28 mi | 0% | 4% |
| Sullivan County, TN | 29 mi | 0% | 8% |
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