Llano County, Texas
Shrink-swell clay limits houses without basements on 16% of Llano County's mapped land, a higher share than 65% of US counties. A shallow water table limits basements on 0%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 420 flood losses here since 2016, 2% of them in buildings with basements. 33% 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 Llano County
| Expansive clay (limits slab homes) | 16.1% |
| High water table (limits basements) | 0.0% |
| Septic fields very limited | 86.9% |
| Clay swell (LEP, by area) | 3.2% |
| High-swell land (LEP 6%+) | 4.5% |
| Mapped soil | 618,413 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Keese | 15% | n/a |
| Ligon | 15% | n/a |
| Castell | 12% | n/a |
| Lou | 8% | n/a |
| Voca | 7% | n/a |
| Katemcy | 5% | n/a |
How we count · survey areas TX299 (2025-09-04)
What the numbers mean here
Clay swell averages a linear extensibility of 3.2% by land area here, and 5% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 16% of the mapped land.
Rain over the 12 months to August 2026: 30.44 in, 0.78 in above the 1991-2020 average year of 29.66 in.
USDA rates 87% of the land very limited for septic absorption fields.
Drought
0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 39 of the last 52 weeks; the most was 94.7% of its area, on the March 31, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 71.9% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
420 flood losses since 2016, $17.2 million paid. The worst year was 2018, with 388. Foundations of the buildings, where recorded: 2% basements, 77% slabs, 4% crawl spaces, 17% elevated. Median water depth outside the building: 26 in.
| Year | Flood losses |
|---|---|
| 2016 | 2 |
| 2017 | 2 |
| 2018 | 388 |
| 2019 | 2 |
| 2020 | 0 |
| 2021 | 3 |
| 2022 | 1 |
| 2023 | 0 |
| 2024 | 4 |
| 2025 | 17 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 29.66 in |
| 12 months to August 2026 | 30.44 in (+0.78) |
| 2025 | 31.63 in (+1.97) |
| Wettest year since 1895 | 1919: 52.79 in |
| Driest year since 1895 | 1954: 11.70 in |
| Days with 1 inch or more, normal at LLANO (3 mi away) | 8 |
Homes
| Housing units | 15,788 |
| Median year built | 1990 |
| Built before 1980 | 33% |
| Built 2000 or later | 34% |
| Owner-occupied | 77% |
| Median value, owner-occupied | $356,500 |
| Single-family detached | 73% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Llano County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Horseshoe Bay | 10% | 0% | 3,851 |
| Llano | 7% | 0% | 1,622 |
| Sunrise Beach Village | 1% | 0% | 1,024 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Burnet County, TX | 29 mi | 27% | 0% |
| Gillespie County, TX | 31 mi | 23% | 0% |
| San Saba County, TX | 32 mi | 45% | 1% |
| Mason County, TX | 33 mi | 15% | 0% |
| Blanco County, TX | 35 mi | 28% | 0% |
| Lampasas County, TX | 43 mi | 20% | under 1% |
| McCulloch County, TX | 53 mi | 29% | under 1% |
| Kendall County, TX | 53 mi | 23% | 0% |
Sources: USDA SSURGO (September 4, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status