Design advice needed for a slope
We have a back yard slope about 20 feet high and about 30 feet deep. We just have fruit trees and a few scrubs on the slope. The house is at the bottom of the hill, with about 15 feet of flat grassy area between the slope and the house. The slope is currently not on an irrigation system, but the grassy/flat graden area is. It appears the previous owners tapped into the line that goes through the house. The pressure is good (80 PSI) but is using 1/2" pipes. I'd like to add irrigation to the slope and replace the irrigation for the rest of the garden as well.
I have a few concerns I was hoping to get some feedback on :
1) If I add the slope area to the irrigation, do I need to be worry about backflow back into the house and how's the best way to address it? Does the backflow need to be at the top of the hill?
2) Would it be better to tap into the main?
3) What top of sprinklers should I use? I was thinking of just bubblers.
If anyone knows someone that installs in Orange County, CA please send me a reference as well.