Montgomery County, Texas
Shrink-swell clay limits houses without basements on 15% of Montgomery County's mapped land, a higher share than 64% of US counties. A shallow water table limits basements on 65%.
None of the county is in drought on the September 22, 2026 Drought Monitor map. FEMA's flood data list 6,116 flood losses here since 2016, under 1% of them in buildings with basements. 14% of homes were built before 1980, against 50% nationally; the median home dates from 2004.
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 Montgomery County
| Expansive clay (limits slab homes) | 15.2% |
| High water table (limits basements) | 64.9% |
| Septic fields very limited | 86.4% |
| Clay swell (LEP, by area) | 4.0% |
| High-swell land (LEP 6%+) | 15.4% |
| Urban land, not rated | 4.1% |
| Mapped soil | 688,742 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Conroe | 15% | 0% |
| Fetzer | 9% | n/a |
| Splendora | 7% | n/a |
| Woodville | 7% | n/a |
| Sorter | 5% | n/a |
| Boy | 5% | n/a |
How we count · survey areas TX339 (2025-09-04)
What the numbers mean here
Clay swell averages a linear extensibility of 4.0% by land area here, and 15% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 15% of the mapped land.
On 65% of Montgomery County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 37.34 in, 13.32 in below the 1991-2020 average year of 50.66 in.
USDA rates 86% of the land very limited for septic absorption fields.
Drought
0% of the county is in drought (D1 or worse) on the September 22, 2026 map. Part of the county was in drought in 35 of the last 52 weeks; the most was 100% of its area, in 9 weeks, most recently on the April 7, 2026 map.
| Category, September 22, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 80% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
6,116 flood losses since 2016, $471.3 million paid. The worst year was 2017, with 2,445. Foundations of the buildings, where recorded: under 1% basements, 90% slabs, 2% crawl spaces, 8% elevated. Median water depth outside the building: 20 in.
| Year | Flood losses |
|---|---|
| 2016 | 1,660 |
| 2017 | 2,445 |
| 2018 | 50 |
| 2019 | 1,297 |
| 2020 | 13 |
| 2021 | 53 |
| 2022 | 7 |
| 2023 | 42 |
| 2024 | 503 |
| 2025 | 19 |
| 2026 to date | 27 |
Rain
| Average year, 1991-2020 | 50.66 in |
| 12 months to August 2026 | 37.34 in (-13.32) |
| 2025 | 43.31 in (-7.35) |
| Wettest year since 1895 | 1973: 73.72 in |
| Driest year since 1895 | 1917: 20.40 in |
| Days with 1 inch or more, normal at CONROE (2 mi away) | 15.5 |
Homes
| Housing units | 266,019 |
| Median year built | 2004 |
| Built before 1980 | 14% |
| Built 2000 or later | 60% |
| Owner-occupied | 72% |
| Median value, owner-occupied | $346,200 |
| Single-family detached | 68% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Montgomery County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Conroe | 10% | 64% | 42,431 |
| Cut and Shoot | 1% | 49% | 367 |
| Magnolia | 2% | 75% | 1,820 |
| Montgomery | 81% | 27% | 1,226 |
| Oak Ridge North | 0% | 42% | 1,135 |
| Panorama Village | 0% | 63% | 1,090 |
| Patton Village | 3% | 59% | 631 |
| Roman Forest | under 1% | 76% | 904 |
| Shenandoah | 0% | 48% | 2,278 |
| Splendora | 1% | 53% | 763 |
| Stagecoach | 11% | 75% | 230 |
| Willis | 15% | 85% | 2,373 |
| Woodbranch | 3% | 49% | 603 |
| Woodloch | 7% | 38% | 136 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| San Jacinto County, TX | 28 mi | 16% | 42% |
| Walker County, TX | 31 mi | 40% | 63% |
| Harris County, TX | 31 mi | 25% | 53% |
| Grimes County, TX | 33 mi | 61% | 40% |
| Waller County, TX | 35 mi | 24% | 40% |
| Liberty County, TX | 39 mi | 46% | 76% |
| Polk County, TX | 52 mi | 23% | 45% |
| Madison County, TX | 53 mi | 52% | 48% |
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