How does floodproofing of a structure specifically reduce flood damages, as opposed to channel improvements or levees?

Floodproofing of a structure specifically reduces flood damages by modifying individual buildings and their components to withstand the direct impacts of floodwaters, rather than attempting to prevent the flood itself or divert it from an entire area. This approach focuses on making the structure resilient when floodwaters reach it, directly mitigating damage at the building level. There are two primary methods: dry floodproofing and wet floodproofing. Dry floodproofing involves making a building watertight up to a specific flood elevation. This is achieved by applying sealants, coatings, or membranes to exterior walls, and installing removable or permanent barriers over openings such as doors, windows, and utility penetrations before a flood. For example, a homeowner might deploy a watertight panel over a garage door opening. By preventing water from entering the structure, dry floodproofing directly protects the building’s interior, its contents, and mechanical/electrical systems from water damage, mold, and contamination. This preserves the structu....