ZIP 78140 falls in Gonzales County, Texas, where we hold 20 septic-related documents. We have not classified septic-versus-sewer status for this county, and we do not have a per-ZIP parcel count -- see the county page for what we hold and where the records are kept.
ZCTA 78140 is not entirely inside one county. Land-area share is from the 2020 Census ZCTA-to-county relationship file.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| Gonzales County, Texas | 68% | 20 | — | — |
| Wilson County, Texas | 27% | 1 | — | — |
| Guadalupe County, Texas | 3% | 11 | 36,043 | 31,861 |
| Karnes County, Texas | 2% | — | — | — |
Land-area overlap is from the 2020 Census Bureau ZCTA5-to-county relationship file, not an estimate of ours. Parcel and document counts are rows we hold, not a survey of every property in the ZIP. Last verified 2026-09-01.
We have not measured septic-versus-sewer status for this county yet.
ZIP 78140 spans 4 counties: Gonzales County, Texas, Wilson County, Texas, Guadalupe County, Texas, Karnes County, Texas.