Pasadena, CA Environmental Rules: Flood Elevation Requirements (2026)

140 sets Pasadena's baseline flood-hazard construction standard for any new construction or substantial improvement, including manufactured homes, sited in an area the floodplain administrator has identified as flood-prone. The structure must be designed or modified and adequately anchored to prevent flotation, collapse or lateral movement caused by hydrodynamic and hydrostatic loads, including buoyancy, and it must be built with materials and utility equipment resistant to flood damage, using construction methods and practices that minimize flood damage. Electrical, heating, ventilation, plumbing and air-conditioning equipment and other service facilities must be designed or located so water cannot enter or accumulate in those components during a flood.

030 as any reconstruction, rehabilitation, addition or other new development whose cost equals or exceeds 50 percent of the structure's pre-improvement market value, which pulls even remodels of existing flood-prone buildings into these anchoring and materials standards; the definition exempts work that only corrects existing code violations identified by the enforcement official and alterations that preserve a historic structure's designation. 160 layers on utility-specific standards, requiring new and replacement water supply and sanitary sewage systems to be designed to keep flood water from infiltrating the system and to keep the system's own discharge from reaching flood water, and requiring on-site waste disposal systems to be sited so they are neither impaired by nor a source of contamination during flooding. 060, punishable as a misdemeanor.