Keller, TX Environmental Rules: Grading & Drainage (2026)

Grading and drainage on private lots in Keller are regulated by the Engineering Design Standards, the Drainage Criteria Manual, and the Zoning Ordinance. New residential construction must provide positive drainage with a minimum slope, typically 5 percent away from the foundation for the first 10 feet and 2 percent across lawn areas, and must not alter the natural drainage pattern in a way that diverts water onto adjoining properties. Platted drainage easements must remain unobstructed. Any significant cut or fill, often triggered by grading more than 50 cubic yards or creating slopes greater than 3:1, requires a grading plan and permit. Retaining walls over 4 feet in exposed height must be engineered and permitted. New home slabs must be founded above the minimum pad elevation established by the subdivision drainage study, which accounts for the 100-year flood elevation where applicable. Lot grading must tie into existing swales, and roof downspouts should discharge to splash blocks or extensions that do not concentrate flow toward a neighbor. When constructing pools, patios, or additions, owners are responsible for maintaining overall lot drainage. Complaints about flooding caused by a neighbors regrading are a private civil matter under Texas common-law drainage rules, supplemented by municipal nuisance enforcement when a structure or fill blocks a platted easement or public drainage. Development Services reviews grading plans before permit issuance.