Denton, TX Environmental Rules: Stormwater Management (2026)

Denton operates under a Texas Pollutant Discharge Elimination System Phase II MS4 general permit that requires the city to manage stormwater quality and reduce pollutant discharge to area waterways including Hickory Creek, Pecan Creek, and tributaries of the Elm Fork Trinity River. Denton Code of Ordinances Chapter 26 addresses stormwater management and prohibits illicit discharges to the municipal storm sewer system. An illicit discharge includes any non-stormwater discharge such as wash water, chemicals, oil, grease, or sediment that enters storm drains or drainage channels. New development and substantial redevelopment projects must submit a stormwater management plan as part of the site plan review and building permit process. The plan must demonstrate that post-development peak discharge rates do not exceed pre-development rates for the 2-year, 10-year, and 100-year storm events. Stormwater detention and retention facilities must be designed in accordance with the Denton Drainage Design Criteria Manual. Low-impact development practices such as permeable pavement, bioretention cells, and rain gardens are encouraged and may satisfy part of the stormwater quality requirements. Construction sites disturbing one acre or more must obtain a TPDES Construction General Permit and implement a stormwater pollution prevention plan with erosion and sediment controls.