It's important to effectively move rainwater away from your home and foundation. Hydrostatic pressure from rainwater sitting around the foundation can press against and seep through basement walls causing them to bow. Gutters and downspouts move rainwater off the roof to ground level. Storm drain lines move water from downspouts to rain barrels or the city street. The runoff is than captured by the city storms sewer whose purpose is to move rainwater. French drains, which can be added around a home's foundation, move water away from the foundation wall and dissipate water through special holes in the underground drain pipes.