Sherman County, Oregon
USDA's soil survey flags shrink-swell clay on 0% of Sherman County's mapped land and a shallow water table under basements on 1%, both below the national shares of 15% and 29%. 13.5% of the county is in drought on the October 13, 2026 Drought Monitor map.
FEMA's flood data list no flood losses here since 2016. 65% of homes were built before 1980, against 50% nationally; the median home dates from 1960.
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 Sherman County
| Expansive clay (limits slab homes) | 0.0% |
| High water table (limits basements) | 0.6% |
| Septic fields very limited | 72.8% |
| Clay swell (LEP, by area) | 1.5% |
| High-swell land (LEP 6%+) | 0.0% |
| Mapped soil | 531,904 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Condon | 24% | n/a |
| Walla Walla | 24% | n/a |
| Lickskillet | 12% | n/a |
| Anderly | 7% | n/a |
| Bakeoven | 7% | n/a |
| Wrentham | 4% | n/a |
How we count · survey areas OR055 (2025-09-09)
What the numbers mean here
Rain over the 12 months to August 2026: 12.37 in, 0.93 in below the 1991-2020 average year of 13.30 in.
USDA rates 73% of the land very limited for septic absorption fields.
With shrink-swell clay on 0% and a shallow water table on 1% of the land, the soil survey points to neither problem across most of Sherman County; conditions still vary lot by lot.
Drought
13.5% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 38 of the last 52 weeks; the most was 13.5% of its area, in 11 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 | 13.5% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
FEMA's flood data list no flood losses in Sherman County since 2016.
Rain
| Average year, 1991-2020 | 13.30 in |
| 12 months to August 2026 | 12.37 in (-0.93) |
| 2025 | 12.96 in (-0.34) |
| Wettest year since 1895 | 1995: 21.22 in |
| Driest year since 1895 | 1939: 6.74 in |
| Days with 1 inch or more, normal at MORO (6 mi away) | 0.3 |
Homes
| Housing units | 969 |
| Median year built | 1960 |
| Built before 1980 | 65% |
| Built 2000 or later | 19% |
| Owner-occupied | 66% |
| Median value, owner-occupied | $211,800 |
| Single-family detached | 64% |
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 |
|---|---|---|---|
| Gilliam County, OR | 20 mi | 3% | under 1% |
| Wasco County, OR | 29 mi | 15% | 2% |
| Klickitat County, WA | 33 mi | 2% | 5% |
| Hood River County, OR | 48 mi | 0% | 5% |
| Morrow County, OR | 52 mi | 7% | 1% |
| Wheeler County, OR | 56 mi | 27% | 1% |
| Jefferson County, OR | 58 mi | 29% | 1% |
| Yakima County, WA | 73 mi | 2% | 8% |
Sources: USDA SSURGO (September 9, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status