Wasco County, Oregon
Shrink-swell clay limits houses without basements on 15% of Wasco County's mapped land, a higher share than 63% of US counties. A shallow water table limits basements on 2%.
71.7% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 1 flood losses here since 2016. 62% of homes were built before 1980, against 50% nationally; the median home dates from 1973.
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 Wasco County
| Expansive clay (limits slab homes) | 15.1% |
| High water table (limits basements) | 1.8% |
| Septic fields very limited | 93.8% |
| Clay swell (LEP, by area) | 3.0% |
| High-swell land (LEP 6%+) | 15.7% |
| Mapped soil | 1,389,440 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Bakeoven | 13% | n/a |
| Lickskillet | 10% | n/a |
| Condon | 8% | n/a |
| Wamic | 5% | n/a |
| Simas | 5% | n/a |
| Walla Walla | 3% | n/a |
How we count · survey areas OR666 (2025-09-10), OR673 (2025-09-10), OR674 (2025-09-10)
What the numbers mean here
Clay swell averages a linear extensibility of 3.0% by land area here, and 16% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 15% of the mapped land.
Clay shrinks as it dries: 71.7% of the county is in drought on the latest map, and 15% of Wasco County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 18.17 in, 2.17 in below the 1991-2020 average year of 20.34 in.
USDA rates 94% of the land very limited for septic absorption fields.
Drought
71.7% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 42 of the last 52 weeks; the most was 86.2% of its area, on the December 9, 2025 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 71.7% |
| D2 severe or worse | 41% |
| D3 extreme or worse | 3% |
| D4 exceptional | 0% |
Flood losses since 2016
1 flood losses since 2016, $0 paid. The worst year was 2019, with 1.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 1 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 20.34 in |
| 12 months to August 2026 | 18.17 in (-2.17) |
| 2025 | 19.08 in (-1.26) |
| Wettest year since 1895 | 1996: 33.99 in |
| Driest year since 1895 | 1939: 11.49 in |
| Days with 1 inch or more, normal at GOVERNMENT CAMP (30 mi away) | 25.7 |
Homes
| Housing units | 12,198 |
| Median year built | 1973 |
| Built before 1980 | 62% |
| Built 2000 or later | 17% |
| Owner-occupied | 68% |
| Median value, owner-occupied | $367,400 |
| Single-family detached | 63% |
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 |
|---|---|---|---|
| Sherman County, OR | 29 mi | 0% | 1% |
| Hood River County, OR | 34 mi | 0% | 5% |
| Jefferson County, OR | 36 mi | 29% | 1% |
| Gilliam County, OR | 46 mi | 3% | under 1% |
| Clackamas County, OR | 50 mi | 5% | 30% |
| Klickitat County, WA | 52 mi | 2% | 5% |
| Wheeler County, OR | 63 mi | 27% | 1% |
| Multnomah County, OR | 66 mi | 0% | 30% |
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