Grainger County, Tennessee
USDA's soil survey flags shrink-swell clay on 2% of Grainger County's mapped land and a shallow water table under basements on 3%, 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 3 flood losses here since 2016. 31% of homes were built before 1980, against 50% nationally; the median home dates from 1992.
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 Grainger County
| Expansive clay (limits slab homes) | 1.9% |
| High water table (limits basements) | 3.3% |
| Septic fields very limited | 74.0% |
| Clay swell (LEP, by area) | 3.0% |
| High-swell land (LEP 6%+) | 1.9% |
| Mapped soil | 193,700 acres |
How we count · survey areas TN057 (2025-08-28)
What the numbers mean here
Rain over the 12 months to August 2026: 45.63 in, 4.80 in below the 1991-2020 average year of 50.43 in.
USDA rates 74% of the land very limited for septic absorption fields.
With shrink-swell clay on 2% and a shallow water table on 3% of the land, the soil survey points to neither problem across most of Grainger 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 18 of the last 52 weeks; the most was 100% of its area, in 7 weeks, most recently on the May 26, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0.5% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
3 flood losses since 2016, $40,765 paid. The worst year was 2026, with 1.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 1 |
| 2020 | 1 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 50.43 in |
| 12 months to August 2026 | 45.63 in (-4.80) |
| 2025 | 46.85 in (-3.58) |
| Wettest year since 1895 | 2020: 64.91 in |
| Driest year since 1895 | 2007: 32.82 in |
| Days with 1 inch or more, normal at MORRISTOWN WFO (10 mi away) | 10.5 |
Homes
| Housing units | 11,835 |
| Median year built | 1992 |
| Built before 1980 | 31% |
| Built 2000 or later | 31% |
| Owner-occupied | 77% |
| Median value, owner-occupied | $189,200 |
| Single-family detached | 64% |
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 |
|---|---|---|---|
| Hamblen County, TN | 14 mi | 4% | 7% |
| Jefferson County, TN | 16 mi | 0% | 5% |
| Claiborne County, TN | 18 mi | under 1% | 3% |
| Union County, TN | 18 mi | under 1% | 5% |
| Hancock County, TN | 22 mi | 0% | 5% |
| Knox County, TN | 31 mi | 0% | 8% |
| Bell County, KY | 33 mi | 0% | 1% |
| Cocke County, TN | 33 mi | 1% | 6% |
Sources: USDA SSURGO (August 28, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status