Bonner County, Idaho
USDA's soil survey flags shrink-swell clay on under 1% of Bonner County's mapped land and a shallow water table under basements on 14%, both below the national shares of 15% and 29%. 91.9% of the county is in drought on the October 13, 2026 Drought Monitor map.
FEMA's flood data list 6 flood losses here since 2016. 36% of homes were built before 1980, against 50% nationally; the median home dates from 1990.
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 Bonner County
| Expansive clay (limits slab homes) | 0.2% |
| High water table (limits basements) | 13.8% |
| Septic fields very limited | 85.2% |
| Clay swell (LEP, by area) | 1.4% |
| High-swell land (LEP 6%+) | 0.8% |
| Mapped soil | 1,086,869 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Pend Oreille | 8% | n/a |
| Bonner | 6% | n/a |
| Vay | 3% | n/a |
| Treble | 3% | n/a |
| Mission | 2% | n/a |
| Ardtoo | 2% | n/a |
How we count · survey areas ID604 (2025-08-27), ID670 (2025-08-27)
What the numbers mean here
Rain over the 12 months to August 2026: 32.70 in, 3.83 in below the 1991-2020 average year of 36.53 in.
USDA rates 85% of the land very limited for septic absorption fields.
With shrink-swell clay on under 1% and a shallow water table on 14% of the land, the soil survey points to neither problem across most of Bonner County; conditions still vary lot by lot.
Drought
91.9% 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 27 weeks, most recently on the September 29, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 91.9% |
| D2 severe or worse | 68.9% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
6 flood losses since 2016, $11,805 paid. The worst year was 2017, with 2.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 2 |
| 2018 | 1 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 1 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 36.53 in |
| 12 months to August 2026 | 32.70 in (-3.83) |
| 2025 | 33.90 in (-2.63) |
| Wettest year since 1895 | 1897: 52.45 in |
| Driest year since 1895 | 1929: 20.64 in |
| Days with 1 inch or more, normal at SANDPOINT EXP STN (4 mi away) | 4.3 |
Homes
| Housing units | 26,867 |
| Median year built | 1990 |
| Built before 1980 | 36% |
| Built 2000 or later | 34% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $487,900 |
| Single-family detached | 75% |
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 |
|---|---|---|---|
| Boundary County, ID | 29 mi | under 1% | 24% |
| Pend Oreille County, WA | 32 mi | 0% | 11% |
| Kootenai County, ID | 44 mi | 2% | 10% |
| Lincoln County, MT | 56 mi | n/a | n/a |
| Stevens County, WA | 56 mi | 0% | 8% |
| Spokane County, WA | 60 mi | 3% | 16% |
| Shoshone County, ID | 76 mi | under 1% | 4% |
| Benewah County, ID | 76 mi | 1% | 40% |
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