What is the minimum lot size for a septic system in Texas?
TexasReviewed October 2026
For lots in subdivisions created under the current Texas rules, a single-family home on a septic system needs at least 1/2 acre when served by a public water system, or at least 1 acre when there is no public water (for example, a private well). Lots subdivided before January 1, 1988, or with an approved sewage plan from before the rule, may use septic even if smaller, provided all other requirements are met. Many local programs are stricter: Guadalupe County lists a 1-acre minimum, and the Edwards Aquifer recharge zone requires 1 acre per single-family dwelling. Confirm the lot's history and local rules before buying.
Check your local rule. This varies by state, county or city. Your permitting office has the final word; the official lookup pages below show you who that is.