Having finished the excavation of all the rock in the backyard, the next step is to install the irrigation system for the backyard. We have kept two zones, 6 and 7, from the previous layout for this purpose. Zone 7 will be the Bottoms; Zone 6 will be the central backyard.
Since we have not yet put the final layer of top soil on these areas, the idea is we can install the irrigation, and then cover it with the top soil. For the Bottoms, that seems to not be true. It is mostly filled in, and while we were excavating the central backyard, settled. So we have to trench it.
Our initial design for Zone 7 was to run heads down one side, next to the Retaining Wall, and back the other, next to the Jungle. But most of this area is only 9 to 12 feet across, so one head, spraying from 8 to 15 feet, should cover the entire area. So we simply run the lines along the bottom of the Retaining Wall, and stop at the fence.
There is one exception. At the widest point, the entrance to the Bottoms next to the irrigation valves, it seems reasonable to put a head next to the Jungle, since these heads spray not only the Bottoms, but out into the central backyard in the transition from one area to the other.
This results in 6 heads for Zone 7, one head next to the Jungle and 5 spaced out along the Retaining wall from the valve to the fence, approximately 10 feet apart. All of the line is 3/4 inch PVC. The pipe, fittings, and heads ran $76.81 at Home Depot.
Once the lines are laid, and cemented together, we can bury all of this with the pile of good soil that we have left over. We will need additional soil, but this is a start.