Graham County, Arizona
Shrink-swell clay limits houses without basements on 32% of Graham County's mapped land, a higher share than 82% of US counties and the 2nd highest of 15 Arizona counties. A shallow water table limits basements on under 1%.
The soil survey maps 86% of the county's land area; these shares describe the mapped part. 43.6% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 12 flood losses here since 2016. 39% of homes were built before 1980, against 50% nationally; the median home dates from 1987.
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 Graham County
| Expansive clay (limits slab homes) | 32.0% |
| High water table (limits basements) | 0.2% |
| Septic fields very limited | 62.3% |
| Clay swell (LEP, by area) | 5.6% |
| High-swell land (LEP 6%+) | 36.7% |
| Mapped soil | 2,531,978 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Tres Hermanos | 3% | n/a |
| Cloverdale | 3% | n/a |
| Beaumain | 3% | n/a |
| Graham | 3% | n/a |
| Eloma | 2% | n/a |
| Gila | 2% | n/a |
How we count · survey areas AZ662 (2025-08-27), AZ663 (2025-08-27), AZ664 (2025-08-27), AZ665 (2025-08-27), AZ673 (2025-08-27), AZ675 (2025-08-27)
What the numbers mean here
Clay swell averages a linear extensibility of 5.6% by land area here, and 37% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 32% of the mapped land.
Clay shrinks as it dries: 43.6% of the county is in drought on the latest map, and 32% of Graham County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 12.92 in, 2.09 in below the 1991-2020 average year of 15.01 in.
USDA rates 62% of the land very limited for septic absorption fields.
Drought
43.6% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 52 of the last 52 weeks; the most was 100% of its area, in 5 weeks, most recently on the November 18, 2025 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 81.7% |
| D1 moderate drought or worse | 43.6% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
12 flood losses since 2016, $221,438 paid. The worst year was 2016, with 7.
| Year | Flood losses |
|---|---|
| 2016 | 7 |
| 2017 | 0 |
| 2018 | 1 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 2 |
| 2025 | 1 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 15.01 in |
| 12 months to August 2026 | 12.92 in (-2.09) |
| 2025 | 9.95 in (-5.06) |
| Wettest year since 1895 | 1905: 28.94 in |
| Driest year since 1895 | 1924: 7.45 in |
| Days with 1 inch or more, normal at FT THOMAS 2 SW (8 mi away) | 1.1 |
Homes
| Housing units | 14,122 |
| Median year built | 1987 |
| Built before 1980 | 39% |
| Built 2000 or later | 31% |
| Owner-occupied | 73% |
| Median value, owner-occupied | $212,000 |
| Single-family detached | 72% |
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 |
|---|---|---|---|
| Greenlee County, AZ | 43 mi | 35% | 1% |
| Cochise County, AZ | 76 mi | 28% | under 1% |
| Gila County, AZ | 80 mi | 30% | under 1% |
| Pinal County, AZ | 86 mi | 15% | under 1% |
| Grant County, NM | 88 mi | 38% | under 1% |
| Hidalgo County, NM | 97 mi | 34% | 1% |
| Catron County, NM | 109 mi | 23% | under 1% |
| Santa Cruz County, AZ | 112 mi | 16% | 0% |
Sources: USDA SSURGO (August 27, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status