i met with my foremans parents this weekend to help design them a landscape plan, and his dad was talking about how he designed and installed this system nearly 30 years ago. All I could think of was, oh geez. I asked him for a site plan, and he had a copy of the one with the irrigation drawing on it. I was amazed. Precip rates, flow calulations, friction loss, everything. Better design and process than most of the irrigators that I see.\ He had a little book from Rainbird called "How to design your own sprinkler system: Although, he calls a zone a "circuit"