Good day to you all, some of you may be able to help me with my problem. So I have a flat roof and I have a pipe that goes from the roof to the ground and it drains all the water. I want to extend the pipe to a rain barrel, so I can use it for the garden. The rain barrel has an opening at the top where the pipe should go to let out all the water. The problem is that the pipe is lower than where the opening of the rain barrel is. I thought of drilling a hole in the side of the rain barrel and putting a check valve there so the water can go into the rain barrel but not back into the pipe. I just want to know if that will work or if there is another way to like make water go up a pipe and into the rain barrel, thanks!