Blaine County, Idaho
USDA's soil survey flags shrink-swell clay on 11% of Blaine County's mapped land and a shallow water table under basements on 4%, both below the national shares of 15% and 29%. The soil survey maps 71% of the county's land area; these shares describe the mapped part.
68.8% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 193 flood losses here since 2016, 18% of them in buildings with basements. 38% 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 Blaine County
| Expansive clay (limits slab homes) | 11.2% |
| High water table (limits basements) | 3.6% |
| Septic fields very limited | 71.3% |
| Clay swell (LEP, by area) | 3.6% |
| High-swell land (LEP 6%+) | 11.2% |
| Mapped soil | 1,190,491 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| McCarey | 8% | n/a |
| Vitale | 5% | n/a |
| Povey | 4% | n/a |
| Elksel | 4% | n/a |
| Beartrap | 4% | n/a |
| Friedman | 3% | n/a |
How we count · survey areas ID680 (2025-08-27), ID681 (2025-08-27), ID702 (2025-08-27), ID752 (2025-08-27), ID780 (2025-08-27)
What the numbers mean here
Rain over the 12 months to August 2026: 15.88 in, 2.11 in below the 1991-2020 average year of 17.99 in.
USDA rates 71% of the land very limited for septic absorption fields.
With shrink-swell clay on 11% and a shallow water table on 4% of the land, the soil survey points to neither problem across most of Blaine County; conditions still vary lot by lot.
Drought
68.8% 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 | 68.8% |
| D2 severe or worse | 44.8% |
| D3 extreme or worse | 27.2% |
| D4 exceptional | 0% |
Flood losses since 2016
193 flood losses since 2016, $3.2 million paid. The worst year was 2017, with 153. Foundations of the buildings, where recorded: 18% basements, 20% slabs, 52% crawl spaces, 10% elevated. Median water depth outside the building: 10 in.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 153 |
| 2018 | 14 |
| 2019 | 8 |
| 2020 | 1 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 17 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 17.99 in |
| 12 months to August 2026 | 15.88 in (-2.11) |
| 2025 | 18.20 in (+0.21) |
| Wettest year since 1895 | 1907: 30.28 in |
| Driest year since 1895 | 2013: 10.22 in |
| Days with 1 inch or more, normal at PICABO (8 mi away) | 0.7 |
Homes
| Housing units | 15,989 |
| Median year built | 1987 |
| Built before 1980 | 38% |
| Built 2000 or later | 25% |
| Owner-occupied | 74% |
| Median value, owner-occupied | $735,300 |
| 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 |
|---|---|---|---|
| Lincoln County, ID | 30 mi | 16% | 1% |
| Minidoka County, ID | 40 mi | 1% | 7% |
| Camas County, ID | 42 mi | 19% | 22% |
| Butte County, ID | 44 mi | 1% | 2% |
| Jerome County, ID | 51 mi | under 1% | under 1% |
| Gooding County, ID | 52 mi | 26% | under 1% |
| Custer County, ID | 63 mi | 3% | 7% |
| Power County, ID | 74 mi | 1% | 2% |
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