It never seems to rain enough when I need water for my vegetable garden, so I had rain diverters put on the roof above two doorways and big plastic trash cans below. Rain is then diverted to a the trash can. Aware of critters climbing in and mosquitoes laying eggs there, I cut a hole in a lid (about 2x3 inches) and put the lid on the can upside down, allowing the water to go right into its reservoir. It beats putting #10 cans all around the drip line; I might do that too, though, this year, as the garden has grown.