Wylie, TX Environmental Rules: Stormwater Management (2026)

Wylie regulates stormwater and drainage through Chapter 42, Article VI, Prohibition of Illicit Connections and Discharges into the Municipal Separate Storm Sewer System, adopted to comply with the city's National Pollutant Discharge Elimination System (NPDES) permit. Sec. 42-104 sets the core rule: no person may discharge, or cause to be discharged, any material other than stormwater into the MS4 or a watercourse when it causes or contributes to a violation of water quality standards, the city's NPDES permit, or a state-issued discharge permit. Sec. 42-105 fills out that prohibition with a long, non-exclusive list of specific prohibited activities and materials, covering sediment from grading or construction beyond what erosion controls can retain, sanitary sewer cross-connections to the MS4, grease-trap discharges without city approval, motor oil, antifreeze and other vehicle fluids, pool backwash containing chlorine, pesticide and fertilizer runoff, and washwater from pressure washing a building exterior.

Sec. 42-108 separately bars illicit connections to the MS4, including any line conveying sewage, regardless of whether the connection was once lawful. Enforcement runs through the city's director, who can issue warning notices, compliance orders and stop-work orders under Sec. 42-115 through 42-121, with a hearing and appeal process at Sec. 42-117 and 42-123. Sec. 42-125 sets criminal penalties at a fine of not more than $2,000.00 per violation, per day, for violating the article or an order issued under it, and Sec. 42-124 preserves separate civil remedies.