McLennan County, Texas
Shrink-swell clay limits houses without basements on 56% of McLennan County's mapped land, a higher share than 93% of US counties. A shallow water table limits basements on under 1%.
100% of the county is in drought on the September 22, 2026 Drought Monitor map. FEMA's flood data list 118 flood losses here since 2016, 2% of them in buildings with basements. 46% of homes were built before 1980, against 50% nationally; the median home dates from 1983.
Data as of September 22, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, September 22, 2026
of homes built before 1980
Soil under McLennan County
| Expansive clay (limits slab homes) | 55.6% |
| High water table (limits basements) | 0.3% |
| Septic fields very limited | 80.5% |
| Clay swell (LEP, by area) | 7.9% |
| High-swell land (LEP 6%+) | 58.6% |
| Urban land, not rated | 1.4% |
| Mapped soil | 679,162 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Heiden | 9% | 80% |
| Houston Black | 6% | 91% |
| Wilson | 5% | 88% |
| Aledo | 5% | n/a |
| Slidell | 4% | n/a |
| Lott | 4% | n/a |
How we count · survey areas TX309 (2025-09-04)
What the numbers mean here
Clay swell averages a linear extensibility of 7.9% by land area here, and 59% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 56% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 56% of McLennan County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 29.41 in, 8.42 in below the 1991-2020 average year of 37.83 in.
USDA rates 80% of the land very limited for septic absorption fields.
Drought
100% of the county is in drought (D1 or worse) on the September 22, 2026 map. Part of the county was in drought in 23 of the last 52 weeks; the most was 100% of its area, in 12 weeks, most recently on the September 22, 2026 map.
| Category, September 22, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 100% |
| D2 severe or worse | 100% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
118 flood losses since 2016, $3.6 million paid. The worst year was 2026, with 39. Foundations of the buildings, where recorded: 2% basements, 67% slabs, 28% crawl spaces, 2% elevated. Median water depth outside the building: 14 in.
| Year | Flood losses |
|---|---|
| 2016 | 24 |
| 2017 | 2 |
| 2018 | 4 |
| 2019 | 6 |
| 2020 | 8 |
| 2021 | 7 |
| 2022 | 0 |
| 2023 | 3 |
| 2024 | 21 |
| 2025 | 4 |
| 2026 to date | 39 |
Rain
| Average year, 1991-2020 | 37.83 in |
| 12 months to August 2026 | 29.41 in (-8.42) |
| 2025 | 39.92 in (+2.09) |
| Wettest year since 1895 | 2004: 55.51 in |
| Driest year since 1895 | 1954: 16.84 in |
| Days with 1 inch or more, normal at WACO DAM (4 mi away) | 11.6 |
Homes
| Housing units | 108,454 |
| Median year built | 1983 |
| Built before 1980 | 46% |
| Built 2000 or later | 29% |
| Owner-occupied | 62% |
| Median value, owner-occupied | $243,600 |
| Single-family detached | 67% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in McLennan County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Bellmead | 69% | 1% | 3,800 |
| Beverly Hills | 53% | 1% | 720 |
| Bruceville-Eddy | 38% | 0% | 614 |
| Crawford | 35% | 0% | 405 |
| Gholson | 24% | 2% | 529 |
| Hallsburg | 76% | 0% | 181 |
| Hewitt | 61% | under 1% | 6,157 |
| Lacy-Lakeview | 66% | 2% | 3,015 |
| Leroy | 83% | under 1% | 203 |
| Lorena | 52% | 0% | 642 |
| Mart | 81% | 0% | 794 |
| McGregor | 66% | 0% | 2,442 |
| Moody | 81% | 0% | 589 |
| Riesel | 66% | 0% | 531 |
| Robinson | 73% | 1% | 4,474 |
| Ross | 58% | under 1% | 91 |
| Waco | 38% | under 1% | 61,163 |
| West | 50% | under 1% | 951 |
| Woodway | 25% | 0% | 3,968 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Falls County, TX | 26 mi | 72% | 2% |
| Hill County, TX | 30 mi | 53% | 2% |
| Bosque County, TX | 35 mi | 29% | 1% |
| Limestone County, TX | 36 mi | 61% | 10% |
| Coryell County, TX | 37 mi | 26% | under 1% |
| Bell County, TX | 39 mi | 55% | 1% |
| Milam County, TX | 54 mi | 61% | 12% |
| Robertson County, TX | 54 mi | 31% | 19% |
Sources: USDA SSURGO (September 4, 2025) · US Drought Monitor (September 22, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status