I am going to install a new system next week. The homeowner hired his own plumber to stub out for the sprinkler system. The problem is that he did not tap off after the meter (5/8). He tapped off about 75 feet away where the wall hydrant goes out. The wall hydrant is 3/4" all the way from the meter, T'd off the 3/4" with 1", then put his shutoff and drain. Guessing about at least a dozen different elbows that it goes through to get there. Am I safe to design this system at 13 gpm or am I going to have my own plumber come in and redo everything? The mainline coming in is 1" copper and the pressure is about 60 psi. Any suggestions?