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

Tarrant County is regulated as a Phase II Municipal Separate Storm Sewer System (MS4) under TCEQ TPDES General Permit TXR040000, and most cities in the county (Fort Worth, Arlington, Grapevine, Keller, Southlake, Mansfield, North Richland Hills, Euless, Hurst, Colleyville, Haltom City) also hold MS4 permits. The MS4 program requires the county and each permitted city to implement six minimum control measures including public education, illicit discharge detection and elimination, construction-site stormwater runoff control, post-construction stormwater management, and pollution prevention/good housekeeping. Construction sites disturbing 1 acre or more (or smaller lots that are part of a common plan of development totaling 1 acre) must obtain coverage under TCEQ Construction General Permit TXR150000 and prepare a Stormwater Pollution Prevention Plan (SWPPP). SWPPP requirements include BMPs like silt fence, stabilized construction entrances, inlet protection, and regular inspections. Illicit discharges to storm drains (anything other than rainwater) are prohibited by MS4 rules and typically banned by local ordinance. Trinity River, West Fork, Clear Fork, Big Fossil Creek, and many other Tarrant County water bodies are listed on the Texas 303(d) list for various impairments and are subject to TCEQ Total Maximum Daily Loads (TMDLs). The Trinity River Authority coordinates regional stormwater and water-quality planning.