I want to install an above ground irrigation system for our flowers (large flower farm). The part I am having trouble with is how to properly connect to the main water supply without having backflow. I would like to have a setup like below (I will add a blowout to prevent pipe freezing).
The pipe that goes underground will tee off, one end going to a garden faucet, and the other end to the irrigation lines. The pipe will travel 100-150 feet underground and eventually end up 5 feet higher than its starting point. This means it will be above the faucet at its end point. I am unsure what type of backflow prevention I would need, and where I should put it. I figure I need something in the mainline before the tee in the picture, but am not sure what. I read that RPZ is "the best" but am worried about potential flooding.
Also, I live in Maryland and am on Well Water.