Flower Mound, TX Environmental Rules: Grading & Drainage (2026)

Grading and drainage in Flower Mound are governed by Chapter 54 of the Code of Ordinances (Stormwater Management and Drainage) and the development standards in Chapter 98 (Zoning). All new development and significant regrading projects must maintain pre-development drainage patterns and ensure that post-development stormwater runoff rates and volumes do not increase to adjacent properties. A grading permit is required for earth-moving projects that alter existing drainage patterns, remove significant vegetation, or involve cut and fill operations. Residential lot grading must direct stormwater away from building foundations with a minimum slope of 6 inches over the first 10 feet from the foundation. Retaining walls exceeding 4 feet in height require engineering design and a building permit. The Cross Timbers Conservation Development District overlay imposes additional grading restrictions including limits on cut and fill depths, requirements for preservation of natural terrain features, and enhanced vegetative buffer zones along drainage corridors. Detention or retention facilities may be required for development that increases impervious cover beyond pre-development levels. The town engineering department reviews drainage plans for compliance before issuing grading or building permits. Contact Public Works at (972) 874-6405 for grading and drainage inquiries.