Ryan: I am not sure what you refer to as a "trap" I have a 45 degree elbow at the bottom of my 10 inch pipe on the backside of the dam. I have approx 20 feet elevation difference between the intake in the pond and the end of the 10 inch on the backside of the dam. Assuming that the 2 inch vent pipe is set at the bottom of the 10 inch pipe, do you think this arrangement will be sufficient to start the syphon action when the water level of the pond is above the 10 inch pipe?
Rock Creek
