From which floor should draining water in a building begin?

Draining water in a building should begin from the top floor because this approach helps to ensure that any water runoff flows downward, preventing further damage to lower levels. Starting from the top allows for the effective removal of water from the highest point, reducing the likelihood of the water accumulating and causing additional issues on the floors below.

In firefighting and damage control scenarios, addressing the source of water first can mitigate the overall damage. If drainage were to start at lower levels, water that has not yet been removed from above would continue to flow down, which could worsen the situation and delay the effective management of the incident. By prioritizing the upper levels, the operation becomes more systematic and efficient.