Malheur County, Oregon
Shrink-swell clay limits houses without basements on 19% of Malheur County's mapped land, a higher share than 69% of US counties. A shallow water table limits basements on 4%.
93.6% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 7 flood losses here since 2016. 62% of homes were built before 1980, against 50% nationally; the median home dates from 1974.
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 Malheur County
| Expansive clay (limits slab homes) | 19.2% |
| High water table (limits basements) | 4.3% |
| Septic fields very limited | 73.6% |
| Clay swell (LEP, by area) | 4.7% |
| High-swell land (LEP 6%+) | 19.4% |
| Mapped soil | 6,023,530 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Snowmore | 5% | n/a |
| Bogusrim | 5% | n/a |
| Nevador | 5% | n/a |
| Babala | 3% | n/a |
| Drice | 2% | n/a |
| Igert | 2% | n/a |
How we count · survey areas OR641 (2025-09-10), OR644 (2025-09-10), OR645 (2025-09-11)
What the numbers mean here
Clay swell averages a linear extensibility of 4.7% by land area here, and 19% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 19% of the mapped land.
Clay shrinks as it dries: 93.6% of the county is in drought on the latest map, and 19% of Malheur County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 12.17 in, 0.44 in below the 1991-2020 average year of 12.61 in.
USDA rates 74% of the land very limited for septic absorption fields.
Drought
93.6% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 33 of the last 52 weeks; the most was 93.6% of its area, in 18 weeks, most recently on the October 13, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 93.6% |
| D2 severe or worse | 80.6% |
| D3 extreme or worse | 12.7% |
| D4 exceptional | 0% |
Flood losses since 2016
7 flood losses since 2016, $107,787 paid. The worst year was 2017, with 5.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 5 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 2 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 12.61 in |
| 12 months to August 2026 | 12.17 in (-0.44) |
| 2025 | 14.15 in (+1.54) |
| Wettest year since 1895 | 1983: 21.78 in |
| Driest year since 1895 | 1949: 7.47 in |
| Days with 1 inch or more, normal at ROME 2 NW (23 mi away) | 0.1 |
Homes
| Housing units | 11,716 |
| Median year built | 1974 |
| Built before 1980 | 62% |
| Built 2000 or later | 13% |
| Owner-occupied | 63% |
| Median value, owner-occupied | $248,900 |
| Single-family detached | 65% |
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 |
|---|---|---|---|
| Canyon County, ID | 54 mi | 1% | 14% |
| Harney County, OR | 70 mi | 34% | 15% |
| Payette County, ID | 70 mi | 4% | 9% |
| Ada County, ID | 71 mi | 20% | 4% |
| Owyhee County, ID | 83 mi | 27% | 2% |
| Gem County, ID | 85 mi | 19% | 9% |
| Washington County, ID | 96 mi | 33% | 3% |
| Baker County, OR | 105 mi | 47% | 7% |
Sources: USDA SSURGO (September 11, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status