Building permits, zoning and land rules in Medina County, Texas

Medina County requires a $45 floodplain development permit before building or other floodplain development; work cannot start until an Authorization to Construct number is issued, and the permit must be renewed if work remains unfinished after a year¹. We could not confirm a general residential building permit or inspection outside that process; ask your precinct commissioner^1,9. Construction in a regulated unincorporated subdivision generally requires Commissioners Court approval and County Clerk recording of the Final Plat first⁷. Medina County does not enforce the International Building Codes it defers to¹⁰.

Devine, Castroville and Natalia administer their own building permits inside city limits^11,12,13. San Antonio and Lytle reach into Medina County and also administer city building permits^14,15. County septic applications go to Environmental Health; Lytle separately requires approval from its superintendent of utilities^2,4.

Medina County's published permit list identifies floodplain, septic, driveway and utility approvals but does not identify a general building department for unincorporated homes². Ask your precinct commissioner whether another approval or inspection applies to your parcel because a general residential permit remains unconfirmed¹. The Environmental Health Department handles OSSF applications and floodplain permits at 1502 Avenue K, 2nd Floor, Hondo, Texas, phone (830) 741-6195^7,16. Driveway and utility permits come from the commissioner or designee for the relevant precinct⁷. The Ground Water Conservation District handles well registration, with a one-time $10 fee for a domestic or livestock exempt well¹⁷, while the county's 911 Addressing Department assigns the physical address needed for a septic application^1,2.

Unincorporated Medina County appears to have no county zoning ordinance and instead regulates development through subdivision, septic and floodplain rules^2,7. Subdivision minimum average lot areas depend on geological zone and public water or sewer service⁷. Subdivision plats generally require setbacks of 50 feet from state and federal road rights-of-way and 25 feet from other road rights-of-way; different municipal setbacks control in an extraterritorial jurisdiction⁷.

Devine, Castroville and Natalia set their own zoning inside city limits^11,18,19. San Antonio and Lytle reach into Medina County and also set municipal zoning^14,20. Environmental Health remains the county septic application office; Lytle requires a separate septic permit from its superintendent of utilities^2,4.

Medina County Environmental Health handles county OSSF applications, and septic systems must be designed and installed by licensed individuals regardless of lot size or an agricultural plat exception^2,7,21. An owner may obtain the septic permit, but may install the system only with an OSSF installer license^1,21.

For authorization to construct, submit a physical address from 911 Addressing, licensed design, septic locator map, color FEMA floodplain map with the panel or FIRMette number, and legal description showing the owner and property address²¹. Aerobic systems also need a signed maintenance agreement and a notarized affidavit filed with the County Clerk¹. Conventional septic permits cost $200, aerobic permits $400 and reinspections $50²². Pay by cash, money order or individual check payable to Medina County; fees are non-refundable and valid for a year²¹. Inspections occur Monday, Wednesday and Friday and must be booked at least a day ahead²¹. Only about 15.7% of county soils lack severe limits for conventional drain fields, so arrange a site evaluation before choosing a system⁸.

Medina County sets no rule on RV occupancy, tiny-home occupancy, accessory dwellings or temporary camping on unincorporated land, because it has adopted no county zoning ordinance⁵. Sanitation, subdivision and floodplain requirements still apply, so discuss your plan with Environmental Health^2,7. Private on-site wastewater needs Environmental Health approval and licensed design and installation, and floodplain development needs a permit before work begins². Manufactured homes in specified mapped flood zones must meet elevation and permanent anchoring requirements²³. A structure in a regulated subdivision cannot be occupied until it connects to a public or individual water supply and either public sewer or a county-approved on-site wastewater system⁷. City rules vary across Medina County, so confirm the jurisdiction before relying on the unincorporated-area answer¹⁸. We could not confirm county rules for privies or graywater systems; ask Environmental Health before preparing the site¹⁶.

1. Call the 911 Addressing Department for the physical address needed in the septic application^1,2.
2. Ask your precinct commissioner whether a general building permit or inspection applies outside a floodplain, where the requirement remains unconfirmed¹. Confirm that a regulated subdivision's Final Plat is approved and recorded before construction, or that an agricultural exception applies⁷.
3. If the property lacks public or community water, contact the Ground Water Conservation District to register the well².
4. Apply to Environmental Health for the septic permit and licensed design and installation; the published fees are $200 for conventional and $400 for aerobic^1,22.
5. Before any floodplain development, obtain the $45 permit; Environmental Health will require the parcel to comply with subdivision and OSSF rules^2,7.
6. Schedule the septic installation inspection at least one day ahead²¹.
7. Before crossing a public right-of-way with a driveway or utility, get the relevant precinct commissioner's permit⁷.

Confirm whether Medina County's subdivision rules or a city's rules control the parcel, because city zoning varies and extraterritorial-jurisdiction agreements can affect subdivision oversight^7,18. For divided agricultural or ranch land outside municipal limits, verify the qualifying use and absence of land laid out for public dedication; ending the qualifying use triggers platting requirements⁷. An owner can apply to Commissioners Court for a determination acknowledging a plat exception for the specific parcel circumstances; septic and floodplain rules still apply⁷. Get a septic site evaluation before closing: every OSSF needs a county permit, and only about 15.7% of Medina County soils lack severe limits for a conventional drain field^1,8. Check the floodplain map early because all floodplain development needs a permit, and a permit depends on subdivision and OSSF compliance^2,7. If the property lacks public or community water, plan to register its well². A driveway onto a state highway requires the TxDOT access process, while encroachment into a county public right-of-way requires the relevant precinct's permit^7,24.