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.
Best Answer
You have a lot of flexibility, as if there is not enough water flowing out the depth in the gutter will increase, increasing the pressure and flow rate. Here is an online calculator which says a 1/8" hole at 0.036 psig will flow 3.7 gallons per hour. I picked the pressure to be roughly one inch deep water. The flow rate increases with the square root of the pressure.