A: Gutters and downspouts prevent water that falls on the roof from dripping down the sides of the house and collecting near the foundation. Uncontrolled rainwater falling from your roof can lead to many problems. Flooding basements, water intruding into the home, ruined landscaping, dead or damaged plants, soil erosion, stained concrete, swollen siding, rotted decks, deteriorated stucco, and cracked slabs are just a few of the problems that can occur.