Camas County, Idaho
A shallow water table limits basements on 22% of Camas County's mapped land and the 5th highest of 43 Idaho counties. Shrink-swell clay limits houses without basements on 19%.
The soil survey maps 51% of the county's land area; these shares describe the mapped part. 75.5% 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. 41% of homes were built before 1980, against 50% nationally; the median home dates from 1991.
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 Camas County
| Expansive clay (limits slab homes) | 18.6% |
| High water table (limits basements) | 22.2% |
| Septic fields very limited | 95.1% |
| Clay swell (LEP, by area) | 4.3% |
| High-swell land (LEP 6%+) | 20.2% |
| Mapped soil | 347,602 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Simonton | 12% | n/a |
| Roanhide | 9% | n/a |
| Gaib | 9% | n/a |
| Brinegar | 8% | n/a |
| Manard | 7% | n/a |
| Elkcreek | 6% | n/a |
How we count · survey areas ID673 (2025-08-27)
What the numbers mean here
Clay swell averages a linear extensibility of 4.3% by land area here, and 20% 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: 75.5% of the county is in drought on the latest map, and 19% of Camas County's mapped land has shrink-swell clay.
On 22% of Camas County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 18.48 in, 4.07 in below the 1991-2020 average year of 22.55 in.
USDA rates 95% of the land very limited for septic absorption fields.
Drought
75.5% 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 20 weeks, most recently on the September 15, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 75.5% |
| D2 severe or worse | 55.6% |
| D3 extreme or worse | 38% |
| D4 exceptional | 0% |
Flood losses since 2016
FEMA's flood data list no flood losses in Camas County since 2016.
Rain
| Average year, 1991-2020 | 22.55 in |
| 12 months to August 2026 | 18.48 in (-4.07) |
| 2025 | 21.95 in (-0.60) |
| Wettest year since 1895 | 1970: 37.65 in |
| Driest year since 1895 | 2013: 12.99 in |
| Days with 1 inch or more, normal at HILL CITY 1 W (21 mi away) | 0.7 |
Homes
| Housing units | 703 |
| Median year built | 1991 |
| Built before 1980 | 41% |
| Built 2000 or later | 31% |
| Owner-occupied | 80% |
| Median value, owner-occupied | $304,000 |
| Single-family detached | 89% |
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 |
|---|---|---|---|
| Elmore County, ID | 36 mi | 7% | 2% |
| Gooding County, ID | 37 mi | 26% | under 1% |
| Blaine County, ID | 42 mi | 11% | 4% |
| Lincoln County, ID | 47 mi | 16% | 1% |
| Boise County, ID | 58 mi | 3% | 2% |
| Custer County, ID | 59 mi | 3% | 7% |
| Jerome County, ID | 62 mi | under 1% | under 1% |
| Minidoka County, ID | 72 mi | 1% | 7% |
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