Sioux County, Nebraska
USDA's soil survey flags shrink-swell clay on 12% of Sioux County's mapped land and a shallow water table under basements on 1%, both below the national shares of 15% and 29%. 100% 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. 73% of homes were built before 1980, against 50% nationally; the median home dates from 1956.
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 Sioux County
| Expansive clay (limits slab homes) | 11.8% |
| High water table (limits basements) | 1.3% |
| Septic fields very limited | 65.7% |
| Clay swell (LEP, by area) | 2.3% |
| High-swell land (LEP 6%+) | 13.4% |
| Mapped soil | 1,324,876 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Valent | 16% | n/a |
| Tassel | 12% | n/a |
| Busher | 11% | n/a |
| Oglala | 6% | n/a |
| Jayem | 5% | n/a |
| Ashollow | 5% | n/a |
How we count · survey areas NE165 (2025-09-08)
What the numbers mean here
Rain over the 12 months to August 2026: 12.76 in, 3.78 in below the 1991-2020 average year of 16.54 in.
USDA rates 66% of the land very limited for septic absorption fields.
With shrink-swell clay on 12% and a shallow water table on 1% of the land, the soil survey points to neither problem across most of Sioux County; conditions still vary lot by lot.
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 52 of the last 52 weeks; the most was 100% of its area, in 38 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 | 81.3% |
| D3 extreme or worse | 44.1% |
| D4 exceptional | 2.2% |
Flood losses since 2016
FEMA's flood data list no flood losses in Sioux County since 2016.
Rain
| Average year, 1991-2020 | 16.54 in |
| 12 months to August 2026 | 12.76 in (-3.78) |
| 2025 | 16.89 in (+0.35) |
| Wettest year since 1895 | 1915: 28.37 in |
| Driest year since 1895 | 2012: 7.46 in |
| Days with 1 inch or more, normal at AGATE 3 E (3 mi away) | 2 |
Homes
| Housing units | 687 |
| Median year built | 1956 |
| Built before 1980 | 73% |
| Built 2000 or later | 14% |
| Owner-occupied | 60% |
| Median value, owner-occupied | $99,300 |
| Single-family detached | 85% |
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 |
|---|---|---|---|
| Dawes County, NE | 35 mi | 24% | 1% |
| Box Butte County, NE | 38 mi | 2% | 5% |
| Goshen County, WY | 41 mi | 1% | 2% |
| Scotts Bluff County, NE | 43 mi | 2% | 11% |
| Fall River County, SD | 53 mi | 55% | 1% |
| Niobrara County, WY | 55 mi | 10% | 1% |
| Morrill County, NE | 64 mi | under 1% | 13% |
| Banner County, NE | 64 mi | under 1% | 2% |
Sources: USDA SSURGO (September 8, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status