Clark County, Nevada
USDA's soil survey flags shrink-swell clay on under 1% of Clark County's mapped land and a shallow water table under basements on under 1%, both below the national shares of 15% and 29%. 68.4% of the county is in drought on the November 3, 2026 Drought Monitor map, down from 86.3% a week earlier.
FEMA's flood data list 25 flood losses here since 2016. 18% of homes were built before 1980, against 50% nationally; the median home dates from 1998.
Data as of November 3, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, November 3, 2026
of homes built before 1980
Soil under Clark County
| Expansive clay (limits slab homes) | 0.4% |
| High water table (limits basements) | 0.4% |
| Septic fields very limited | 75.4% |
| Clay swell (LEP, by area) | 1.8% |
| High-swell land (LEP 6%+) | 0.7% |
| Mapped soil | 4,736,570 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Weiser | 5% | n/a |
| Zeheme | 3% | n/a |
| Arizo | 3% | n/a |
| Purob | 3% | n/a |
| St. Thomas | 3% | n/a |
| Boxspring | 2% | n/a |
How we count · survey areas NV608 (2025-08-28), NV755 (2025-08-29), NV757 (2025-09-02), NV788 (2025-09-02)
What the numbers mean here
Rain over the 12 months to August 2026: 5.63 in, 1.64 in below the 1991-2020 average year of 7.27 in.
USDA rates 75% of the land very limited for septic absorption fields.
With shrink-swell clay on under 1% and a shallow water table on under 1% of the land, the soil survey points to neither problem across most of Clark County; conditions still vary lot by lot.
Drought
68.4% of the county is in drought (D1 or worse) on the November 3, 2026 map. Part of the county was in drought in 52 of the last 52 weeks; the most was 100% of its area, in 9 weeks, most recently on the October 20, 2026 map.
| Category, November 3, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 68.4% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
25 flood losses since 2016, $931,145 paid. The worst year was 2023, with 11.
| Year | Flood losses |
|---|---|
| 2016 | 5 |
| 2017 | 2 |
| 2018 | 1 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 1 |
| 2022 | 3 |
| 2023 | 11 |
| 2024 | 1 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 7.27 in |
| 12 months to August 2026 | 5.63 in (-1.64) |
| 2025 | 6.72 in (-0.55) |
| Wettest year since 1895 | 1941: 15.73 in |
| Driest year since 1895 | 2002: 1.99 in |
| Days with 1 inch or more, normal at LAS VEGAS MCCARRAN AP (13 mi away) | 0.2 |
Homes
| Housing units | 948,995 |
| Median year built | 1998 |
| Built before 1980 | 18% |
| Built 2000 or later | 45% |
| Owner-occupied | 58% |
| Median value, owner-occupied | $431,000 |
| Single-family detached | 60% |
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 |
|---|---|---|---|
| Mohave County, AZ | 79 mi | 6% | under 1% |
| Lincoln County, NV | 99 mi | 6% | 1% |
| Washington County, UT | 111 mi | 4% | 1% |
| San Bernardino County, CA | 114 mi | 1% | under 1% |
| Inyo County, CA | 130 mi | n/a | n/a |
| Nye County, NV | 145 mi | 3% | 4% |
| Iron County, UT | 150 mi | 6% | 1% |
| Yavapai County, AZ | 174 mi | 29% | under 1% |
Sources: USDA SSURGO (September 2, 2025) · US Drought Monitor (November 3, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status