The District operates a municipal separate storm sewer system (MS4) that is regulated by the Texas Commission on Environmental Quality (TCEQ) under its Texas Pollutant Discharge Elimination System (TPDES) general permit number TXR040000.  Under this program, the District developed a Storm Water Management Program (SWMP) that outlines actions that the District will take to ensure compliance with the Clean Water Act and the Texas Water Code.  The plan is organized around seven control measures:
        1. Public Education and Outreach 
        2. Public Involvement/Participation 
        3. Illicit Discharge Detection and Elimination  
        4. Construction Site Runoff Control 
        5. Post-Construction Site Runoff Control 
        6. Good Housekeeping/Pollution Prevention
        7. Authorization for Municipal Construction Activities

A link to the District's Stormwater Management Program is below.

What is storm water runoff?

Storm water runoff is water that flows after a rainfall. During rainstorms, water drains off driveways, parking lots and streets picking up pollutants while flowing to the storm sewer system. Once storm water enters the storm sewer system of inlets, pipes or channels, it flows downstream to the nearest creek, lake or river. 

What is urban runoff?

Urban runoff also flows to the storm sewer system. Urban runoff is water from irrigation, overwatering, car washing and other sources that travel into the street picking up pollutants. 

What is the difference between the storm sewer system and sanitary sewer system?

The water that goes down the sanitary sewer system (from sinks or toilets) flows to a wastewater treatment plant where it is treated and filtered prior to entering any water bodies.

The storm water and urban runoff water that flows down driveways and streets and into the storm sewer system flows directly to our creeks, lakes and rivers. Anything that enters a storm sewer system is discharged untreated into the water bodies we use for swimming, fishing, and providing drinking water. 

The effects of pollution

Polluted storm water runoff can have many adverse effects on plants, fish, animals and people.

  • Sediment can cloud the water and make it difficult or impossible for aquatic plants to grow.
  • Sediment also can destroy aquatic habitat.
  • Bacteria and other pathogens can wash into swimming areas and create health hazards.
  • Excess nutrients can cause algae blooms. When algae die, they sink to the bottom and decompose in a process that removes oxygen from the water. Fish and other aquatic organisms can’t exist in water with low dissolved oxygen levels.
  • Household hazardous wastes like insecticides, pesticides, paint, solvents, grease, used motor oil and other auto fluids can poison aquatic life. Land animals and people can become sick or die from eating diseased fish or ingesting polluted water.
  • Debris—plastic bags, six-pack rings, bottles and cigarette butts—washed into creeks and waterbodies can choke, suffocate, or disable aquatic life like ducks, fish, turtles and birds.

Polluted storm water often affects drinking water sources. This, in turn, can affect human health and increase drinking water treatment costs.

What can you do to help?

For more information or to inquire about volunteer opportunities call (512) 255-7871 x408 or e-mail To report illegal dumping into our storm drains or waterways, contact the District at (512) 255-7871 x410. The largest source of storm water pollution are pollutants such as litter, pet waste, pesticides, fertilizers, leaves and yard clippings and automotive leaks and spills. These materials are swept away with the storm water and produce what is referred to as non-point source pollution. Harmful bacteria, chemicals, sediment and litter enters or blocks the storm drain and leads to flooding, impaired water quality and endangers the health and habitat of local wildlife.