Which of the following best describes floodproofing?

Floodproofing is best described as making a building watertight. This technique involves implementing measures that prevent floodwaters from entering a structure, which can include the construction of barriers, sealing openings, and using watertight doors and windows. The goal is to minimize or entirely eliminate flood-related damage to the building while allowing it to remain in its current location within the floodplain.

In contrast, elevating a building above flood levels is a different flood mitigation method focused primarily on raising the structure to avoid floodwaters. Building an area for floodwater to flow freely typically refers to design strategies that accommodate or redirect floodwaters, which do not confer watertight protection to the building itself. Completely removing a building from a floodplain is a more drastic approach that involves relocating the structure outside of any flood-prone area, thus eliminating exposure to flood risks, but this does not address floodproofing as a technique.