A part used roll of 100 mm diameter perforated pipe appears long enough to use for a stormwater planter project. The initial design for the planters includes 750 mm depth of filter medium, 50 mm rock mulch, and a further ponding of 300 mm. Upon inspection the pipe is found to have perforations of 8 x 1.5 mm on six sides, repeated every 3 cm along the pipe. To calculate the maximum flow rate, first the open area per meter is calculated: | A part used roll of 100 mm diameter perforated pipe appears long enough to use for a stormwater planter project. The initial design for the planters includes 750 mm depth of filter medium, 50 mm rock mulch, and a further ponding of 300 mm. Upon inspection the pipe is found to have perforations of 8 x 1.5 mm on six sides, repeated every 3 cm along the pipe. To calculate the maximum flow rate, first the open area per meter is calculated: |