It is Practical question. We have a reservoir near to our agricultural land water is 12ft below and 200 mtrs away from the pumping station. I want get water upto pumping station with gravity. For that I propose to dig a trench and lay 110 mm pvc pipe and bury it, and also planning to dig a open well at pumping station to use siphon at the end. What will be depth needed for the trench (I want to the trench to as deep as possible since it is difficult to prime the siphon) and depth of well for getting average 15 Litters per second.