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Leander, Texas
Inside Leander's city limits, shrink-swell clay limits houses without basements on 48% of mapped land, higher than 55% of Texas cities. A shallow water table limits basements on under 1%.
That clay share is below Williamson County's 60%. FEMA's flood data list 34 flood losses since 2016 in ZIP code 78641 overlapping the city. Of its 27,000 homes, 3% were built before 1980; the median dates from 2013.
Data as of October 13, 2026 · sources · in Williamson County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 1 overlapping ZIP
of homes built before 1980
Foundation repair in Leander
Foundation repair in Leander: shrink-swell clay limits slab homes on 48% of Leander's mapped land, more than in 55% of Texas cities.
About 22,300 of Leander's 27,000 homes are detached houses.
| Who designs the repair | The ASCE Texas Section's repair guidelines say a Texas-licensed engineer should evaluate the foundation and design the repair (2022 guidelines) |
| Prices | Cost guide ranges compared |
Soil under Leander city limits
| Expansive clay (limits slab homes) | 48.3% |
| High water table (limits basements) | 0.1% |
| Septic fields very limited | 86.7% |
| Clay swell (LEP, by area) | 5.8% |
| High-swell land (LEP 6%+) | 47.4% |
| Mapped soil | 25,541 acres |
What the numbers mean here
Clay swell averages a linear extensibility of 5.8% by land area here, and 47% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 48% of the mapped land.
Clay shrinks as it dries: 100% of Williamson County is in drought on the latest map, and 48% of Leander's mapped land has shrink-swell clay.
USDA rates 87% of the land very limited for septic absorption fields.
Drought in Williamson County
100% of Williamson County is in drought (D1 or worse) on the October 13, 2026 map. County detail.
Flood losses by ZIP code
FEMA flood records since 2016 in the ZIP codes that overlap Leander. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 78641 | 97% | 34 | $2.1 million |
Homes in Leander
| Housing units | 27,000 |
| Median year built | 2013 |
| Built before 1980 | 3% |
| Built 2000 or later | 85% |
| Owner-occupied | 73% |
| Median value, owner-occupied | $506,200 |
| Single-family detached | 83% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Cedar Park | 5 mi | 48% | 0% |
| Liberty Hill | 7 mi | 56% | 0% |
| Jonestown | 7 mi | 2% | 0% |
| Volente | 9 mi | 1% | 0% |
| Lago Vista | 11 mi | 4% | 0% |
| Georgetown | 12 mi | 42% | under 1% |
| Round Rock | 12 mi | 56% | under 1% |
| Point Venture | 15 mi | under 1% | 0% |
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · Census ACS 2020-2024. Methods · Data status