First a little history and site description: We are currently installing and maintaining a system that at this point is 516 - 45 - 75 gpm zones. 7 - Rainbird LXD and 2 - Tucor RKD controllers with 17 water meters and 5 water wells. This is a large residential community growing very fast (150 - 175 homes a year) so the city water lines (West Side) come in from both sides of the community. One 12" city main comes from the newly developed side and another 10" city main comes into the other end of the community (East Side) after is supplies 10 year old plus neighborhood. Water pressure on the west side is around 90 psi and the east side is 50 psi which is where our issues are coming. Now, we have spoken with the utility and physically check all of the city isolation valves to verify they are open. I have the city main as-builds that show the water line crossing the major blvd in this community and we have at times a 40 psi difference literally crossing this blvd. There is a elevation change that we estimate is 35' from one 2" meter reading 89 psi to another 2" reading 51 psi. ***Now that I have put all of you to sleep Seriously, I just wanted to put it all out there and provide all the details: Several RB 5505 zones run #8 to #12 at 65-70 gpm and for this discussion we had 2 zones going at the same time. Meter A had static pressure of 91 psi and meter B has 49, but meter B was moving 10 gpm and A was ripping at 120 gpm. I am assuming the back pressure from meter A is keeping B meters volume down since 5505's are nozzled to operate at 50 psi. We have plenty of water to run 3 zones technically, but meter B operating at an even lower dynamic pressure really affects the larger rotor zones. I have dealt with pressure problems over the last 15 years and if I am right the only solution is going to be installing a booster pump for meter B. I really want to know your thoughts and if I am seeing this the wrong way I definitely want to know! Sorry for the long post and boring read, but I need to address this problem with management and I really want to be prepared and be able to present solutions. Thank you in advance for your replies and assistance Side note: This is happening with several areas in this community, so do not get hung up with the scheduling of the zones. Our biggest issue with all of this right now is the water window.