About Our Storm Water Permit

MS4 Permit

San Antonio was originally issued a National Pollutant Discharge Elimination System (NPDES) Permit as required by the Clean Water Act of 1972 by the Environmental Protection Agency (EPA) in 1996 (San Antonio Permit Number – TXS001901). This permit established basic structures and procedures for regulating discharge of pollutants into public waterways.

The original NPDES permit expired in 2001.  This permit was subsequently replaced in 2003 by a Texas Pollutant Discharge Elimination System (TPDES) Permit administered by the Texas Commission on Environmental Quality (TCEQ) (San Antonio Renewal Permit Number – 04284).

The permit governs all areas within the corporate boundary of the city which are served by the municipal separate storm sewer system (MS4) owned and operated by its permittees.

2011 TPDES MS4 Permit (PDF)

Municipal Separate Storm Sewer System (MS4)

MS4 Coverage Areas

The MS4 for San Antonio & Bexar County discharges water runoff to various drainage ditches, tributaries and other channels that eventually flow into the following San Antonio River Basin waterways:

  • Medina River (Below Medina Diversion Lake)
  • Lower Leon Creek
  • Upper Leon Creek
  • Upper Cibolo Creek
  • Salado Creek
  • Upper San Antonio River
  • Medio Creek
  • Mid Cibolo Creek

Texas Commission on Environmental Quality (TCEQ)
U.S. Environmental Protection Agency (EPA)

MS4 Permittees & Responsibilities

San Antonio’s Phase I MS4 Permit is held and administered by the following permittees:

All permittees are responsible for conducting the following:

  • Ensuring compliance with permit conditions related to discharges from portions of the MS4 for which each permittee owns and operates
  • Implementation of an approved Storm Water Management Program (SWMP)
  • Annual reporting
  • Collection of representative wet weather monitoring data
  • Plan of actions to assume responsibility for implementation of permit requirements on portions of the MS4 they own/operate if standing agreements are dissolved

MS4 - San Antonio Storm Water Management Program

Permit obligations include: 

  • Preventing and prohibiting the discharge of pollutants into the MS4 to the Maximum Extent Practicable.
  • Implementation of an approved Storm Water Management Program (SWMP) designed by the permittees which determines what measures must be in place in order to be in compliance.

The City of San Antonio SWMP consists of:

  • Comprehensive outline of pollution prevention measures, treatment or removal techniques, storm water monitoring, use of legal authority and other appropriate means to control the quality of storm water discharged from the MS4.
  • Identification of areas of jurisdiction for all permittees, as well as program element applicability on a specific area basis.

Under the Phase I MS4 permit, the City of San Antonio is required to oversee, manage and implement governing operations/measures for the following:

  1. Structural controls and storm water collection system operations
  2. Areas of new development and/or significant redevelopment
  3. Roadways
  4. Flood control projects
  5. Pesticide, herbicide and fertilizer applications
  6. Illicit discharges and improper disposal
  7. Spill prevention and response
  8. Industrial and high risk runoff
  9. Construction site runoff
  10. Public education/public participation
  11. Monitoring program

Storm Water Fee

San Antonio City Ordinance establishes monthly storm water fees and rate schedules for San Antonio residents, businesses and other water users in order to help support operations, maintenance, engineering/design and capital improvements related to San Antonio’s storm water infrastructure.

The storm water fee is billed by San Antonio Water System (SAWS). All storm water operations, drainage maintenance and enhancement projects are managed and coordinated through the City’s Public Works department.

COSA Public Works - Storm Water Utility Fee

About Remember the River

Remember the River is a community campaign focused on nonpoint source pollution prevention outreach and education. The campaign is led by the City of San Antonio.

All campaign education and outreach efforts are conducted in compliance with educational/outreach guidelines established under a TPDES Phase I Municipal Separate Storm Sewer System (MS4) discharge permit regulated by the Texas Commission on Environmental Quality.

Contact Us

Darlene Dorsey 210.207.1011

Email Address:
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Mailing Address:
P.O. Box 839966
San Antonio, TX 78283-3966