Jefferson County, Alabama
USDA's soil survey flags shrink-swell clay on 2% of Jefferson 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, after 3.7% a week earlier.
FEMA's flood data list 366 flood losses here since 2016, 10% of them in buildings with basements. 59% of homes were built before 1980, against 50% nationally; the median home dates from 1975.
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 Jefferson County
| Expansive clay (limits slab homes) | 2.2% |
| High water table (limits basements) | 3.1% |
| Septic fields very limited | 50.8% |
| Clay swell (LEP, by area) | 1.7% |
| High-swell land (LEP 6%+) | 2.2% |
| Urban land, not rated | 9.7% |
| Mapped soil | 719,860 acres |
How we count · survey areas AL073 (2025-09-10)
What the numbers mean here
Rain over the 12 months to August 2026: 48.02 in, 8.37 in below the 1991-2020 average year of 56.39 in.
USDA rates 51% 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 Jefferson 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 22 of the last 52 weeks; the most was 100% of its area, in 6 weeks, most recently on the April 28, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 30.1% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
366 flood losses since 2016, $11.4 million paid. The worst year was 2021, with 162. Foundations of the buildings, where recorded: 10% basements, 36% slabs, 24% crawl spaces, 30% elevated. Median water depth outside the building: 13 in.
| Year | Flood losses |
|---|---|
| 2016 | 4 |
| 2017 | 35 |
| 2018 | 18 |
| 2019 | 7 |
| 2020 | 53 |
| 2021 | 162 |
| 2022 | 53 |
| 2023 | 13 |
| 2024 | 8 |
| 2025 | 8 |
| 2026 to date | 5 |
Rain
| Average year, 1991-2020 | 56.39 in |
| 12 months to August 2026 | 48.02 in (-8.37) |
| 2025 | 49.48 in (-6.91) |
| Wettest year since 1895 | 1929: 78.29 in |
| Driest year since 1895 | 2007: 30.19 in |
| Days with 1 inch or more, normal at BIRMINGHAM AP (9 mi away) | 17.7 |
Homes
| Housing units | 310,789 |
| Median year built | 1975 |
| Built before 1980 | 59% |
| Built 2000 or later | 20% |
| Owner-occupied | 64% |
| Median value, owner-occupied | $240,000 |
| Single-family detached | 69% |
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 |
|---|---|---|---|
| Shelby County, AL | 24 mi | 2% | 9% |
| Walker County, AL | 29 mi | 0% | 6% |
| Blount County, AL | 35 mi | 9% | 10% |
| St. Clair County, AL | 36 mi | 0% | 12% |
| Bibb County, AL | 39 mi | 1% | 30% |
| Cullman County, AL | 40 mi | 0% | 21% |
| Tuscaloosa County, AL | 41 mi | 1% | 16% |
| Talladega County, AL | 43 mi | 1% | 20% |
Sources: USDA SSURGO (September 10, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status