A downspout is a vertical pipe attached to the side of a building that carries rainwater from the roof gutters down to the ground. When rain falls on your roof, it flows into gutters (the horizontal channels along the roof's edge), and the downspout is where all that water exits the system, usually depositing it several feet away from the building's foundation.

You've probably noticed these pipes running down the corners of houses and schools. They're typically made of metal or plastic and might be square, rectangular, or round. Without downspouts, water would pour off the roof in sheets, creating puddles right next to the foundation and potentially damaging the building over time.

Some downspouts connect to underground pipes that carry water even farther away, while others simply empty onto the ground or into rain barrels. During a heavy storm, you can watch a downspout at work: water gushes through it like a small waterfall.