Today I completed the basic installation of my Gray Water Irrigation system for my High Density Orchard. The system brings water from my surge tank (a rubbermaid garbage can) through a 400 micron filter (that only removes the really big stuff) and to the orchard via 3/4" poly tubing.
In the above pictures the Surge tank and Filter is underneath the stairway in the first pic, the 3/4" main line can be seen on the right hand side of all of the pics and it also runs along the fence line with the grapevines.
Once the Gray Water reaches the Orchard via the 3/4 poly line it is distributed throughout the planting area via 1/2" dripper line. This dripper line has emitters spaced every 12" along it's length and I have spaced the lines every 4' running generally with the contours of the area. What the heck does that mean? It means that the rows themselves are basically level but each row is lower down the slope of the land than the previous. Originally I thought my Orchard sloped from the NE corner down to the SW corner which would have forced me to orient the rows on the bias running NW-SE, but when I dug out the laser it showed that I had only a very slight E-W slope with the main slope being N-S. Consequently I ran my lines E-W, located 1' N of each row of trees.
The first picture shows the layout of the emitter lines in relation to the trees, the following pics show the dispersal of the Gray Water from the emitters.
In a traditional drip irrigation system for a planting such as an orchard you would irrigate each individual tree with three or four emitters located in a circular pattern roughly at the drip-line of the tree. What's the drip-line of the tree you say? It is the circle defined by where the rain would drip off of the leaves of the tree. This system is designed to water each individual tree, additionally common knowledge (which everyone knows ain't necessarily correct) has it that this type of irrigation should be done slowly and infrequently to encourage deep root growth. This deep root growth is supposed to allow the tree to tap into buried sources of nutrients and provide a secure foundation.