Hamilton County, Tennessee
USDA's soil survey flags shrink-swell clay on 8% of Hamilton County's mapped land and a shallow water table under basements on 13%, both below the national shares of 15% and 29%. 10.1% of the county is in drought on the October 13, 2026 Drought Monitor map, down from 48.6% a week earlier.
FEMA's flood data list 177 flood losses here since 2016, 5% of them in buildings with basements. 48% of homes were built before 1980, against 50% nationally; the median home dates from 1982.
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 Hamilton County
| Expansive clay (limits slab homes) | 7.7% |
| High water table (limits basements) | 13.2% |
| Septic fields very limited | 70.2% |
| Clay swell (LEP, by area) | 2.7% |
| High-swell land (LEP 6%+) | 7.7% |
| Urban land, not rated | 4.4% |
| Mapped soil | 368,400 acres |
How we count · survey areas TN065 (2025-08-28)
What the numbers mean here
Rain over the 12 months to August 2026: 43.13 in, 13.99 in below the 1991-2020 average year of 57.12 in.
USDA rates 70% of the land very limited for septic absorption fields.
With shrink-swell clay on 8% and a shallow water table on 13% of the land, the soil survey points to neither problem across most of Hamilton County; conditions still vary lot by lot.
Drought
10.1% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 47 of the last 52 weeks; the most was 100% of its area, in 30 weeks, most recently on the July 14, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 10.1% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
177 flood losses since 2016, $4.8 million paid. The worst year was 2025, with 61. Foundations of the buildings, where recorded: 5% basements, 24% slabs, 41% crawl spaces, 30% elevated. Median water depth outside the building: 15 in.
| Year | Flood losses |
|---|---|
| 2016 | 2 |
| 2017 | 6 |
| 2018 | 29 |
| 2019 | 9 |
| 2020 | 54 |
| 2021 | 8 |
| 2022 | 4 |
| 2023 | 0 |
| 2024 | 4 |
| 2025 | 61 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 57.12 in |
| 12 months to August 2026 | 43.13 in (-13.99) |
| 2025 | 53.12 in (-4.00) |
| Wettest year since 1895 | 1973: 74.57 in |
| Driest year since 1895 | 2007: 34.62 in |
| Days with 1 inch or more, normal at CHATTANOOGA LOVELL AP (9 mi away) | 16.1 |
Homes
| Housing units | 168,013 |
| Median year built | 1982 |
| Built before 1980 | 48% |
| Built 2000 or later | 29% |
| Owner-occupied | 64% |
| Median value, owner-occupied | $312,800 |
| Single-family detached | 68% |
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 |
|---|---|---|---|
| Catoosa County, GA | 18 mi | 18% | 22% |
| Sequatchie County, TN | 19 mi | 1% | 3% |
| Bradley County, TN | 19 mi | under 1% | 14% |
| Marion County, TN | 24 mi | under 1% | 7% |
| Dade County, GA | 27 mi | 6% | 7% |
| Whitfield County, GA | 28 mi | 6% | 33% |
| Walker County, GA | 30 mi | 7% | 21% |
| Bledsoe County, TN | 30 mi | 2% | 4% |
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