Frisco, TX Environmental Rules: Stormwater Management (2026)

Section 34-331's general prohibition bars any person from introducing, or causing to be introduced, a discharge into the municipal separate storm sewer system (MS4) that is not composed entirely of stormwater. The code carves out an affirmative defense for 19 specific categories of nonstormwater flow, including water line flushing, air conditioning condensation, individual residential vehicle washing, dechlorinated swimming pool discharges, and diverted stream or groundwater flows, but that defense disappears once the Development Engineering Services (DES) determines a particular discharge is a source of pollutants, notifies the discharger in writing, and the discharge continues more than 14 calendar days after that notice.

Construction sites disturbing five or more acres must additionally submit a stormwater pollution prevention plan and a notice of intent under Section 34-334 before starting work. Enforcement under Article IX runs through the DES and Compliance Enforcement Authority (CEA), who can issue warning notices, notices of violation, compliance orders, and, for imminent endangerment, emergency cease-and-desist orders that can cut off a property's water, sewer or other utility service; a noncompliant construction site can also be issued a 'red tag' halting all further work. Judicial enforcement under Section 34-339 lets the city petition the state district court or the county court at law of Collin or Denton County, reflecting Frisco's split across both counties, for a civil penalty of up to $1,000 per day for most violations and up to $5,000 per day for an unlawful point-source pollutant discharge into the MS4, on top of a criminal fine of up to $2,000 per day per violation.