I design most systems at 10 to 11 gpm in my area (3/4" main and 5/8" meter). Today I'm looking at my first design of the season. It too has a 3/4" main (type k copper) and a 5/8" meter. The only diference is this house sits way back off the street (flag lot). The 3/4" copper main from the street to the house measures 200'. The pressure is way too high, 120 psi (will have to be regulated down to 70). I figure I can only pull 7 to 8 gpm out of this to keep pressure loss low and velocity safe. The entire yard will be rotors with a max of 3 per zone. Have any of you had to design a system with such a low design gpm?