Land near San Marcos.

San Marcos-area land: verify city limits, ETJ, platting and county permits

For land near San Marcos, first determine who reviews the parcel. The Census reference point for San Marcos falls in Hays County, but an address or city name does not prove that a tract is inside city limits, in the City of San Marcos ETJ, inside another city’s jurisdiction, or in unincorporated Hays County. Start with the City’s Address Lookup and current ETJ map, then compare the result with the deed, survey, appraisal account and recorded plat. Ask the relevant planning office to confirm the reviewing authority for the exact legal description and proposed work.

The City’s Development Code page lists a version effective June 16, 2026 and says the code applies to applicable development within City limits and its ETJ. San Marcos publishes planning-case information for annexation, zoning and subdivision plats. Its administrative plat viewer is limited to approved plats through October 2, 2023 and does not show recorded plats; the City directs users to the applicable County Clerk for recorded documents. Save the dated map and case results and obtain recorded plats, easements and restrictions before assuming a tract can be divided or used as planned.

For a tract in unincorporated Hays County, County Development Services says a development permit is required for development, with examples including buildings, sheds, grading, fill and creek crossings. Hays County separately states that newly constructed, replacement or altered on-site sewage facilities need permits. Its development process identifies different roles for Development Services, Transportation and the Fire Marshal depending on the project. Confirm city/county/ETJ status, prior plat compliance, floodplain review, driveway authority, water and wastewater service, and OSSF feasibility in writing before setting a budget or purchase condition. The Rural Land Feasibility Planner can organize your own estimates; it does not determine permits, buildability or system design.

Facts to help plan the next check

• The San Marcos Development Code page lists a code version effective June 16, 2026 and states that the code applies to applicable development, improvements, land, structures, construction, modifications and uses in City limits and the City ETJ.
• The City’s Interactive Maps page offers an Address Lookup to check whether a specific address is in San Marcos City limits or ETJ.
• San Marcos Planning Cases lists annexation, zoning and subdivision/plat matters and says the City’s administrative plat viewer shows approved plats only through October 2, 2023 and does not replace recorded plats from the applicable county clerk.
• The City GIS ETJ layer describes the ETJ boundary and identifies agreements with Kyle, New Braunfels and Uhland, so a simple distance ring is not a substitute for the mapped boundary.
• Hays County says development in unincorporated areas requires a development permit and provides examples including buildings, sheds, grading, fill and creek crossings.
• Hays County states that all newly constructed OSSF, replacement systems and alterations to existing OSSF require a permit.
• Hays County’s development process identifies separate permitting roles for Development Services, Transportation and the Fire Marshal based on project scope.

Parcel-specific next checks

1. Match the listing to the deed, legal description, survey and county appraisal account; do not treat a San Marcos mailing address or Census centroid as a property boundary.
2. Use San Marcos Address Lookup and the current City ETJ map, then ask City Planning to confirm the reviewing jurisdiction for the exact tract.
3. Request recorded plats, deeds, easements, restrictions and prior planning cases from the correct County Clerk and agencies; the City administrative plat viewer is limited to approved plats through October 2, 2023.
4. Ask San Marcos Planning which version of the Development Code and platting requirements apply to the location and proposed work.
5. For unincorporated Hays County land, confirm parcel compliance and the required development, floodplain, driveway, utility and fire-safety permits with each responsible department.
6. If onsite wastewater may be needed, check septic jurisdiction and request the site evaluation, system design, permit history, maintenance records and current requirements from Hays County.
7. Verify public water and wastewater availability, utility-provider service boundaries and extension costs directly with the provider; nearby lines do not guarantee service.
8. Use a surveyor and qualified environmental, engineering or septic professionals to assess boundaries, easements, flood, drainage, soil and the intended use.
9. Keep dated map results, written agency responses and source links with your purchase due-diligence file.

Sources

• City of San Marcos — current Development Code and applicability ↗
• City of San Marcos — address lookup, city limits and ETJ maps ↗
• City of San Marcos — planning cases and recorded-plat distinction ↗
• City of San Marcos GIS — ETJ boundary layer and interlocal agreements ↗
• Hays County — development and floodplain permit FAQ ↗
• Hays County — OSSF permits for new, replacement and altered systems ↗
• Hays County — development, platting and permit process ↗

Research checked 2026-11-07. Confirm current details for the exact parcel.

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