I am attempting to build a waterfall out of a gutter system. I currently have an awning that is 72" by 48" with 3" high (tentatively) buffers on each side to keep the water from flowing off. The awning is tilted 95 degrees downward from the side of a building. Connected to the awning I have a gutter with the cross-sectional dimensions below and a length of approximately 72" plus or minus 5". I plan on drilling holes in the bottom of the gutter along a linear path so that a waterfall will be created, but I am not sure the amount of surface area I need to create with the holes in order to balance the amount of water/rate that is flowing in and keep the gutter from overflowing. Any help in this would be greatly appreciated.