Tarrant County, TX Environmental Rules: Grading & Drainage (2026)

Tarrant County has limited general authority to require grading permits on existing lots under Texas Local Government Code Chapter 232 (which focuses on subdivision platting). However, several layered controls apply. New subdivisions must submit drainage analysis and plans during platting review by Tarrant County Public Works, demonstrating that post-development runoff does not exceed pre-development runoff for design storms (typically 5, 10, 25, and 100-year). Floodplain development permits are required for any fill or grading in mapped Special Flood Hazard Areas under NFIP rules. Sites disturbing 1 acre or more need TCEQ TXR150000 coverage and a SWPPP including grading-phase BMPs. Under Texas common law, the rule for surface-water drainage is a modified common-enemy rule with reasonable-use elements: an upper landowner cannot accelerate or concentrate runoff onto a neighbor, and neither can a lower landowner dam up natural flow. This is called the Texas Water Code 11.086 rule, codified from common law, and allows private lawsuits. Building in natural drainage courses typically requires engineering review and may trigger floodplain or Corps of Engineers jurisdiction if the course is a Water of the US. Incorporated cities almost all have grading permits for residential and commercial work, so check city rules within Fort Worth, Arlington, Grapevine, and suburbs.