The objective in excavating Zone 2 is to get the irrigation lines in place. This involves both the Zone 2 irrigation line and the Zone 3 irrigation line. The new Zone 3 areas will be the North and South beds. We left a 4 inch PVC pipe to get the lines thru the walkway into these beds.
Running the water line to the South bed is fairly simple. I just extended the existing one inch line down a couple of inches, across the zone 2 digging and then put in a "tee" to split off for the North bed.
Going thru the 4 inch PVC pipe thru the walkway, we can then continue straight over to the South bed.
From the tee, we want to go to the North bed, and thru the 4 inch PVC pipe that goes under the walkway and into the North bed. First we need to dig out all the dirt from the water supply line to the North bed. This is taking days. We are trying to get the dirt out of the way, excavate the rocks out of the hole, and do as little damage as possible to the root structure of the tree, keeping in mind that it's been a long dry summer for the tree. We need to balance the damage we do to the tree's root structure now against the hopefully better environment it will have once all the rocks are out of the way and better soil is used instead.
Using the jackhammer, we have all of the rock out of the way, and have the sprinkler line installed. This is all 1" (one inch) PVC, and goes straight from the tee, across Zone 2 and then up and thru the 4-inch PVC into the North bed, where it is currently just capped off.
With the sprinkler line installed, we can then fill this back in with dirt -- dirt mixed with leaves and grass and compost.