Invite butterflies and birds to your yard with a rain garden that helps protect rivers and lakes from water pollution. Shallow depressions in the soil that are planted with native flowers and grasses, rain gardens collect rain and melting snow, naturally absorbing them into the ground. Most people direct downspouts from rooftops into their rain gardens. However, you can also use them to absorb water from hillsides, driveways, and other impervious surfaces.