Draft Flood Maps Could Add Thousands of Bexar County Homes to Flood Zones — Here's What to Know

If you own, rent, buy or sell property in Bexar County, new draft flood maps released by the San Antonio River Authority deserve your full attention. The maps propose adding 5,639 buildings and 5,007 parcels to flood zones while removing 3,577 buildings and 3,333 parcels. The net effect is thousands of San Antonio-area properties facing a potential change in flood risk designation — and with it, real consequences for insurance costs, mortgage requirements and property values.

The updated maps came from a full restudy of three major watersheds: the Upper San Antonio, Salado and Medina. That restudy used updated rainfall data, which means the underlying science reflects a more current picture of how water moves through this region during heavy storm events. San Antonio's history with flooding — from flash floods along low-lying creek corridors to longer inundation events after prolonged rain — makes accurate flood mapping genuinely important, not just a paperwork exercise.

These are draft maps, and there is still a meaningful process ahead before anything becomes official. FEMA must issue a preliminary release, then communities have a formal appeal period to challenge the data or methodology, and only after that can local governments adopt the updated maps. That process typically takes months, sometimes longer. So if your property appears on the draft maps as newly included in a flood zone, you are not required to buy flood insurance today. But you should start gathering information now, because the process moves faster than most people expect.

For home buyers, this is a critical due-diligence moment. If you are shopping for a home in areas near the Upper San Antonio River corridor — think neighborhoods on the south and southeast sides — or near Salado Creek, which runs through portions of the north and northeast sides, or near the Medina River and its tributaries in the southwest, you should ask your agent and your lender whether the property you are considering appears on the draft maps. A home that is newly placed in a Special Flood Hazard Area, commonly called a 100-year floodplain, will typically require federally backed flood insurance if you have a federally backed mortgage. That added annual cost can affect how much home you can afford.

For home sellers, the draft maps create a disclosure consideration. Texas law requires sellers to disclose known material facts about a property. While these maps are not yet official, a seller who is aware that a property may be newly designated as flood-prone has reason to discuss the situation with a real estate attorney. Getting ahead of this now — rather than having it surface during a buyer's inspection or title review — protects everyone involved and keeps transactions from falling apart late in the process.

For renters, the picture is a bit different but still matters. Renter's insurance does not cover flood damage, and your landlord's property insurance almost certainly does not cover your personal belongings in a flood. If your apartment complex, house rental or condominium sits near one of these three watersheds, it is worth checking whether your building appears on the draft maps. If it does, a separate flood insurance policy for renters is worth pricing out. FEMA's National Flood Insurance Program offers contents-only coverage for renters at rates that are often lower than people assume.

For current homeowners who are not planning to sell or move, the draft maps still matter in two practical ways. First, if your property is newly added to a flood zone and you carry a federally backed mortgage, your lender will eventually require flood insurance once the maps are officially adopted. Second, even if you own your home free and clear, a flood designation affects resale value and can affect your ability to get certain types of financing in the future. Knowing what is coming gives you time to price flood insurance, explore a Letter of Map Amendment if you believe your property has been incorrectly mapped, or make improvements that could support a lower insurance rating.

The communities most directly touched by this restudy — those along the Upper San Antonio, Salado and Medina watersheds — span a broad geography that includes portions of the City of San Antonio as well as surrounding municipalities such as Leon Valley, Helotes, Converse, Schertz and areas further into southwestern Bexar County near the Medina River. School districts in these areas, from Northside ISD and North East ISD in the north and northwest to South San Antonio ISD and Harlandale ISD in the south, serve neighborhoods that in some cases sit very close to these watercourses.

The bottom line: these maps are not final, and there is time to respond thoughtfully. Pull up the San Antonio River Authority's resources, talk with your lender, consult your insurance agent, and bring your real estate professional into the conversation early. Being informed now is far better than being surprised after the maps become official.