Subdividing in Austin without city water or sewer: what a plat has to prove

Last verified August 7, 2026 against the Austin Land Development Code · Kimbrough Gray · KiliGray Homes

A plat may not be approved unless the subdivider satisfies §25-4-197. Without a water utility, the subdivider must give the director evidence that water suitable for human consumption can be obtained on the land. Without a sanitary sewer utility, if the local health authority has not approved on-site sewage facilities, the subdivider must construct a community sewage collection and treatment system serving each lot.

Applies to: Subdivision of land inside the City of Austin that is not served by a water utility, a sanitary sewer utility, or both. In the Travis County portion of the extraterritorial jurisdiction, §30-2-197 applies instead and differs in its detail.

It is a condition of plat approval, not a later problem

§25-4-197(A) is blunt about where this sits in the sequence:

A plat may not be approved unless the subdivider has complied with the requirements of this section, if applicable.

So on land without city water or sewer, the water and wastewater question is answered before the plat — not during design and not at building permit. It is a gate on creating the lots at all.

Without a water utility: prove water is there

The subdivider must give the director evidence that water suitable for human consumption may be obtained from surface or subsurface sources on the land. The section names the kind of evidence that will do:

results of tests and borings;
statements from local and state health authorities;
statements from water engineers; and
statements from other competent authorities.

Note the standard: water obtainable on the land. This is not a question of whether water can be trucked or piped in — it is whether the land itself will yield potable water.

And if you go further and propose a private water supply for the subdivision, the plans and specifications must be prepared by a registered professional engineer and approved by two bodies — the director of the Water and Wastewater Utility, and the state environmental agency.

The code names an agency that no longer exists under that name. §25-4-197 requires approval by, and compliance with the regulations of, the Texas Natural Resource Conservation Commission. TNRCC was renamed the Texas Commission on Environmental Quality (TCEQ) in 2002. The rest of Austin's code has largely caught up — the current name appears nine times across the chapters we hold, the old name twice, and this section is one of the two. We quote the code as written; you will be dealing with TCEQ.

Without a sewer utility: septic first, community system second

This is the part most often misread. §25-4-197(C) requires a community sewage system only when both of these are true:

the subdivision is not to be served by a sanitary sewer utility; and
the use of private on-site sewage facilities has not been approved by the local health authority.

So approved septic is what avoids the community-system obligation. Reading (C) as an unconditional requirement would suggest every unserved West Austin subdivision needs its own treatment plant, which is not what the section says.

Where a community system is required, it must:

serve each lot — collection and treatment;
be designed and located per the state environmental agency's regulations and the local health authority's; and
have its plans approved by the director of the Water and Wastewater Utility.

Going the septic route

§25-4-198 sets the path. A subdivision to be served by private on-site sewage facilities must comply with Chapter 15-5 (Private Sewage Facilities) of the City Code — a different chapter, not part of the Land Development Code, and not covered on this hub.

Procedurally, the local health authority reviews the preliminary plan or plat and reports its findings to the review department. That is the approval referred to in §25-4-197(C), so the health authority's report is what determines which of the two routes you are on.

If you later demolish and rebuild on such a lot, abandoning the existing system is governed by the same Chapter 15-5 — see utilities before demolition.

Inside the city or in the ETJ? West Austin spans both. This page is the city rule, §25-4-197. In the Travis County portion of the extraterritorial jurisdiction, §30-2-197 applies instead — same title, different text. It routes the water evidence through the platting official rather than the director and structures its requirements differently. We have not transcribed it, and this page does not summarise it. Establish which jurisdiction the land is in before relying on either.

Common questions

Can you subdivide land in Austin without city water and sewer?

Yes, but §25-4-197 makes it a condition of plat approval. Without a water utility the subdivider must provide evidence that water suitable for human consumption can be obtained on the land. Without a sewer utility, either the local health authority approves on-site sewage facilities or a community sewage system serving each lot must be built.

What evidence does Austin accept that a lot has water?

Evidence that water suitable for human consumption may be obtained from surface or subsurface sources on the land — which may include the results of tests and borings and statements from local and state health authorities, water engineers and other competent authorities.

Do I need a community sewage system to plat in Austin without sewer?

Only if the local health authority has not approved private on-site sewage facilities. §25-4-197(C) requires a community collection and treatment system serving each lot where there is no sanitary sewer utility and septic has not been approved.

What rules govern septic systems in an Austin subdivision?

Chapter 15-5 (Private Sewage Facilities) of the City Code, under §25-4-198. The local health authority reviews the preliminary plan or plat and reports its findings to the review department.

Who approves a private water supply for an Austin subdivision?

The plans and specifications must be prepared by a registered professional engineer and approved by the director of the Water and Wastewater Utility and by the state environmental agency — which the code still calls the Texas Natural Resource Conservation Commission, renamed TCEQ in 2002.

Are the rules different outside Austin city limits?

Yes. §30-2-197 governs subdivisions without water or wastewater service in the Travis County portion of Austin's extraterritorial jurisdiction. It covers the same ground as the city section but is differently worded, including routing evidence through the platting official.

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We do this research ourselves on every project we take on — zoning, floodplain, watershed, trees, whether it is a legal lot. Send us an address and we will run it and tell you what we find. It works the same whether you own a vacant lot, a house you are thinking of adding a unit to, or a house you are thinking of replacing. No charge and no strings, and if it is a bad lot we will say so.

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We are homebuilders, not the City of Austin. This page explains how we read the code in practice — it is not legal advice and it is not an official determination. Always confirm with Austin Development Services before you rely on it for a project. The authoritative text is the Austin Land Development Code; permitting questions go to Austin Development Services Department.