I've purchased a home that has an existing irrigation system installed that is hooked up to a well that is exclusively supplying the irrigation system. I live in FL in a very flat area, so we have minimal elevation between the water supply and the pump, and the yard is flat so no elevation changes throughout the entire system relative to the location of the pump.
The pump supplies the system directly and is connected to a pump start relay switch, for context.
That said, I need to redesign the layout of the system, move some heads, potentially create new zones, etc., because the way it's set up now is not optimal and doesn't work with landscaping changes I will be making.
What I need to figure out is what GPM and PSI I'm getting at the supply, but I want to avoid disconnecting the well from the system to figure that out if possible. Does anyone have an idea? Can I just shut off all the heads on one zone, and then add a pressure gauge in place of one of the heads (I would use the zone that is furthest from the supply and test at the very end of that line) and then build my system around that PSI, or is that making it too simple? Anywhere else in the system should be higher PSI than at that point which is furthest away, right?
Then, can I use that PSI to determine GPM, or do I need additional information?