Got a really good customer of mine that wants 1.25 acres under irrigation and it's been many years since i have done a system this large. We are trying to get away with the least zones possible due to the rocky nature of the soil on the property. I am trying to remember what a 1" copper pipe will flow at 40 PSI. The well pump is 1.5HP 20-25 Gal per minute, 290' deep with static level of 240' per the installer. I would imagine the 20-25 GPM is with the 1 1/2 main line wide open and no pressure. Cannot find consistency between flow charts i find online! 1 says 38 GPM and another says 13.5 GPM for a 1" line at 40 PSI! Any help would be appreciated. Normally i would sub a job like this out but all companies here are at least 3-4 weeks out and we need to get sod down as winter is on it's way!!! Thanks!