Humboldt County, Nevada
Shrink-swell clay limits houses without basements on 21% of Humboldt County's mapped land, a higher share than 70% of US counties and the 3rd highest of 17 Nevada counties. A shallow water table limits basements on 9%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 3 flood losses here since 2016. 33% 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 Humboldt County
| Expansive clay (limits slab homes) | 20.6% |
| High water table (limits basements) | 9.3% |
| Septic fields very limited | 82.3% |
| Clay swell (LEP, by area) | 4.1% |
| High-swell land (LEP 6%+) | 23.2% |
| Mapped soil | 6,202,688 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Boton | 5% | n/a |
| Soughe | 3% | n/a |
| Devada | 2% | n/a |
| Ninemile | 2% | n/a |
| Burrita | 2% | n/a |
| Rocconda | 2% | n/a |
How we count · survey areas NV760 (2025-09-02), NV777 (2025-09-02), NV792 (2025-09-02)
What the numbers mean here
Clay swell averages a linear extensibility of 4.1% by land area here, and 23% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 21% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 21% of Humboldt County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 10.03 in, 1.38 in below the 1991-2020 average year of 11.41 in.
USDA rates 82% of the land very limited for septic absorption fields.
Drought
100% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 33 of the last 52 weeks; the most was 100% of its area, in 28 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 | 100% |
| D2 severe or worse | 53.8% |
| D3 extreme or worse | 10.7% |
| D4 exceptional | 0% |
Flood losses since 2016
3 flood losses since 2016, $19,054 paid. The worst year was 2017, with 3.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 3 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 11.41 in |
| 12 months to August 2026 | 10.03 in (-1.38) |
| 2025 | 10.30 in (-1.11) |
| Wettest year since 1895 | 1983: 22.10 in |
| Driest year since 1895 | 1929: 6.15 in |
| Days with 1 inch or more, normal at OROVADA 3 W (19 mi away) | 0.4 |
Homes
| Housing units | 7,768 |
| Median year built | 1991 |
| Built before 1980 | 33% |
| Built 2000 or later | 27% |
| Owner-occupied | 74% |
| Median value, owner-occupied | $278,300 |
| Single-family detached | 50% |
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 |
|---|---|---|---|
| Pershing County, NV | 68 mi | 11% | 4% |
| Washoe County, NV | 93 mi | 34% | 3% |
| Lander County, NV | 119 mi | 11% | 6% |
| Harney County, OR | 123 mi | 34% | 15% |
| Malheur County, OR | 126 mi | 19% | 4% |
| Owyhee County, ID | 128 mi | 27% | 2% |
| Churchill County, NV | 129 mi | 11% | 11% |
| Modoc County, CA | 135 mi | 27% | 15% |
Sources: USDA SSURGO (September 2, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status