Flower Mound, TX Environmental Rules: Stormwater Management (2026)

Flower Mound's stormwater management program is governed by Chapter 54 of the Code of Ordinances (Stormwater Management and Drainage) and the town's TPDES MS4 general permit issued by the Texas Commission on Environmental Quality (TCEQ). The town straddles two major watersheds: the Denton Watershed draining to Lake Grapevine and the Elm Fork Trinity Watershed draining to Lake Lewisville. All construction projects disturbing one acre or more of land must obtain a TPDES Construction General Permit and implement a Stormwater Pollution Prevention Plan (SWPPP) with erosion and sediment controls. Post-construction stormwater quality measures are required for new development to maintain pre-development runoff rates and volumes. The Cross Timbers Conservation Development District (CTCDD) overlay imposes additional environmental protections including enhanced stormwater detention and water quality treatment for development within the overlay zone. Illicit discharge to the storm sewer system is prohibited. Residents may not discharge pool water, vehicle wash water, or other pollutants into storm drains. The town maintains a storm drain marking program and conducts dry-weather screening of outfalls. Contact Public Works at (972) 874-6405 for stormwater inquiries or to report illicit discharges.