Roanoke County, Virginia
USDA's soil survey flags shrink-swell clay on 4% of Roanoke County's mapped land and a shallow water table under basements on 2%, both below the national shares of 15% and 29%. 13.4% of the county is in drought on the October 13, 2026 Drought Monitor map, down from 100% a week earlier.
FEMA's flood data list 83 flood losses here since 2016, 63% of them in buildings with basements. 54% of homes were built before 1980, against 50% nationally; the median home dates from 1978.
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 Roanoke County
| Expansive clay (limits slab homes) | 4.0% |
| High water table (limits basements) | 2.5% |
| Septic fields very limited | 81.7% |
| Clay swell (LEP, by area) | 2.0% |
| High-swell land (LEP 6%+) | 4.0% |
| Urban land, not rated | 2.2% |
| Mapped soil | 157,684 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Hayesville | 13% | 0% |
| Dekalb | 11% | n/a |
| Weikert | 11% | 0% |
| Edneyville | 8% | n/a |
| Frederick | 6% | 23% |
| Tumbling | 5% | n/a |
How we count · survey areas VA161 (2025-09-05)
What the numbers mean here
Rain over the 12 months to August 2026: 29.86 in, 14.88 in below the 1991-2020 average year of 44.74 in.
USDA rates 82% of the land very limited for septic absorption fields.
With shrink-swell clay on 4% and a shallow water table on 2% of the land, the soil survey points to neither problem across most of Roanoke County; conditions still vary lot by lot.
Drought
13.4% 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 46 weeks, most recently on the October 6, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 13.4% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
83 flood losses since 2016, $1.6 million paid. The worst year was 2018, with 55. Foundations of the buildings, where recorded: 63% basements, 12% slabs, 5% crawl spaces, 21% elevated. Median water depth outside the building: 17 in.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 1 |
| 2018 | 55 |
| 2019 | 1 |
| 2020 | 22 |
| 2021 | 0 |
| 2022 | 1 |
| 2023 | 1 |
| 2024 | 0 |
| 2025 | 1 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 44.74 in |
| 12 months to August 2026 | 29.86 in (-14.88) |
| 2025 | 39.59 in (-5.15) |
| Wettest year since 1895 | 2020: 65.67 in |
| Driest year since 1895 | 1930: 21.71 in |
| Days with 1 inch or more, normal at LAFAYETTE 1 NE (6 mi away) | 9.1 |
Homes
| Housing units | 42,331 |
| Median year built | 1978 |
| Built before 1980 | 54% |
| Built 2000 or later | 19% |
| Owner-occupied | 76% |
| Median value, owner-occupied | $286,000 |
| Single-family detached | 76% |
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 |
|---|---|---|---|
| Salem city, VA | 8 mi | under 1% | 3% |
| Craig County, VA | 10 mi | 3% | 15% |
| Roanoke city, VA | 13 mi | 1% | 1% |
| Montgomery County, VA | 15 mi | 33% | 6% |
| Radford city, VA | 25 mi | 19% | 5% |
| Monroe County, WV | 25 mi | 2% | 14% |
| Botetourt County, VA | 27 mi | 10% | 12% |
| Giles County, VA | 28 mi | 10% | 4% |
Sources: USDA SSURGO (September 5, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status