Shelby County, Alabama
USDA's soil survey flags shrink-swell clay on 2% of Shelby County's mapped land and a shallow water table under basements on 9%, 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 49.8% a week earlier.
FEMA's flood data list 195 flood losses here since 2016, 10% of them in buildings with basements. 16% of homes were built before 1980, against 50% nationally; the median home dates from 1997.
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 Shelby County
| Expansive clay (limits slab homes) | 1.6% |
| High water table (limits basements) | 9.2% |
| Septic fields very limited | 79.6% |
| Clay swell (LEP, by area) | 2.4% |
| High-swell land (LEP 6%+) | 1.6% |
| Mapped soil | 518,430 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Townley | 18% | n/a |
| Nauvoo | 17% | n/a |
| Sunlight | 13% | n/a |
| Allen | 7% | n/a |
| Weogufka | 6% | n/a |
| Nella | 5% | n/a |
How we count · survey areas AL117 (2025-09-10)
What the numbers mean here
Rain over the 12 months to August 2026: 44.74 in, 11.47 in below the 1991-2020 average year of 56.21 in.
USDA rates 80% of the land very limited for septic absorption fields.
With shrink-swell clay on 2% and a shallow water table on 9% of the land, the soil survey points to neither problem across most of Shelby 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 27 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 | 53.5% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
195 flood losses since 2016, $10.3 million paid. The worst year was 2021, with 153. Foundations of the buildings, where recorded: 10% basements, 62% slabs, 11% crawl spaces, 17% elevated. Median water depth outside the building: 18 in.
| Year | Flood losses |
|---|---|
| 2016 | 2 |
| 2017 | 13 |
| 2018 | 7 |
| 2019 | 5 |
| 2020 | 8 |
| 2021 | 153 |
| 2022 | 5 |
| 2023 | 0 |
| 2024 | 1 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 56.21 in |
| 12 months to August 2026 | 44.74 in (-11.47) |
| 2025 | 53.36 in (-2.85) |
| Wettest year since 1895 | 1929: 78.87 in |
| Driest year since 1895 | 2007: 30.08 in |
| Days with 1 inch or more, normal at ALABASTER SHELBY CO AP (9 mi away) | 16.6 |
Homes
| Housing units | 91,995 |
| Median year built | 1997 |
| Built before 1980 | 16% |
| Built 2000 or later | 44% |
| Owner-occupied | 81% |
| Median value, owner-occupied | $326,100 |
| Single-family detached | 77% |
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 |
|---|---|---|---|
| Jefferson County, AL | 24 mi | 2% | 3% |
| Chilton County, AL | 29 mi | 3% | 19% |
| Talladega County, AL | 29 mi | 1% | 20% |
| Bibb County, AL | 32 mi | 1% | 30% |
| Coosa County, AL | 33 mi | 1% | 10% |
| St. Clair County, AL | 37 mi | 0% | 12% |
| Clay County, AL | 46 mi | 2% | 15% |
| Blount County, AL | 49 mi | 9% | 10% |
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