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San Marcos, TX Environmental Rules: Flood Elevation Requirements (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Freeboard
2 feet above BFE
Applies to
AE, AH, AO zones
Certification
PE, architect, or surveyor
Nonresidential option
Floodproofing to same level

Summary

San Marcos requires new construction and substantial improvements in AE, AH, and AO flood zones to elevate the lowest floor two feet above base flood elevation.

All new construction or substantial improvements of residential structures must have the lowest floor (including basement) elevated to two feet above the base flood elevation.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 41).

Full Breakdown

City Code Sec. 39.043 sets the local freeboard standard: residential and nonresidential structures built or substantially improved in AE, AH, or AO special flood hazard zones must have their lowest floor, including any basement, elevated to two feet above the base flood elevation (BFE) shown on FEMA's FIRM. A registered professional engineer, architect, or land surveyor must certify the elevation to the floodplain administrator. Nonresidential buildings may floodproof to that same two-foot-above-BFE level instead of elevating, but only with a variance and engineer certification. Small detached accessory structures like garages and sheds can qualify for a wet-floodproofing exemption if unoccupied.

Violations & Fines

Building without the required lowest-floor elevation or certified floodproofing blocks permit sign-off and triggers stop-work orders under the floodplain administrator's review; the city may also deny or revoke the development permit under Article II of Chapter 39.

Frequently Asked Questions

Does San Marcos require more than FEMA's minimum flood elevation?
Yes. FEMA's baseline is the BFE itself; San Marcos Sec. 39.043 adds a 2-foot freeboard margin above BFE for the lowest floor.
Can a garage sit below the freeboard elevation in San Marcos?
Enclosed areas below the lowest floor may be used only for parking, storage, or building access, and must have flood vents to equalize hydrostatic pressure.

Sources & Official References

Other rules in San Marcos

Stormwater ManagementSome RestrictionsVehicle Idling RestrictionsSome RestrictionsErosion ControlSome RestrictionsFlood ZonesSome RestrictionsNoise Ordinances: Amplified Music & Outdoor SoundSome RestrictionsNoise Ordinances: Vehicle NoiseSome RestrictionsParking Rules: Commercial & Oversized VehiclesSome RestrictionsParking Rules: Driveway RulesSome RestrictionsParking Rules: Loading ZonesLight RestrictionsFence Regulations: Fence Permit RequirementsSignificant Restrictions

All San Marcos rules

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