Armchair Naturalist: Rain Gardens A rain garden is a planted depression that soaks up and absorbs rainwater runoff from impervious areas like roofs, driveways, walkways, parking lots and compact lawn areas. Come and learn some of the ways you can create rain gardens at home, school or work. Help create areas where rain can return to the soil! Powder Mill Ledges Wildlife Refuge, 12 Sanderson Road, Smithfield, RI; June 14, 2017; 6:30 pm-8:00 pm; Program Fee: $10/member; $14/non-member. Ages: Adult.