Bexar County, TX Environmental Rules: Stormwater Management (2026)

Bexar County is covered by the Texas Commission on Environmental Quality (TCEQ) Municipal Separate Storm Sewer System (MS4) general permit, TXR040000, which imposes six minimum control measures on local jurisdictions including public education, illicit discharge detection, construction site runoff control, and post-construction stormwater management. For individual construction sites, Texas Pollutant Discharge Elimination System (TPDES) Construction General Permit TXR150000 requires any operator disturbing one acre or more, or less than one acre if part of a larger common plan of development, to prepare a Stormwater Pollution Prevention Plan (SWPPP), file a Notice of Intent with TCEQ, and install and maintain best management practices including silt fence, inlet protection, and stabilized construction exits. In addition, any development over the Edwards Aquifer Recharge Zone or Transition Zone, which covers a large arc across northern Bexar County including parts of San Antonio, Castle Hills, and unincorporated areas, is subject to the TCEQ Edwards Aquifer Protection Program. Recharge zone developments disturbing 5 acres or more require a Water Pollution Abatement Plan (WPAP) approved by TCEQ before construction; smaller sites need a Contributing Zone Plan. Post-construction BMPs must capture and treat the first 1.5 inches of runoff.