Coral Gables, FL Environmental Rules: Grading & Drainage (2026)

Coral Gables requires a Public Works permit for grading and drainage modifications through the city's online permit application system. Site grading plans must demonstrate positive drainage away from all structures with a minimum slope of 2% for the first 10 feet from the building foundation. Drainage must not be redirected onto neighboring properties or into the public right-of-way without authorization. The city's high water table—often just below the ground surface—limits the depth of excavation and requires careful consideration of dewatering during construction. Any dewatering operations must not discharge turbid water into the stormwater system. New impervious surfaces such as driveways, patios, and walkways may trigger on-site stormwater retention or detention requirements to offset the increased runoff. The city coordinates with Miami-Dade County for larger drainage infrastructure and canal systems. Retaining walls associated with grading changes may require a separate building permit and structural engineering. All drainage designs must account for the city's flood-prone conditions and FEMA flood zone designations. French drains, swales, and rain gardens may be used for on-site stormwater management with proper permitting. Filling or altering drainage swales in the right-of-way requires Public Works approval.