The 5 Steps:

The irrigation industry has accepted that certain design considerations must be met for a high-quality irrigation system. We have spent years narrowing them down to the following five short steps:

Step 1:  Determine your soil type, to find out whether you should amend your soil.  Go ahead and amend it!

Step 2:  Collect information about the plants to be irrigated, to determine how much water it will take to support them on a regular basis.  For example, are they all 1-gallon Southern California native shrubs that will grow 4' tall when mature?  A mix?

Step 3:  Collect information about the microclimates at the site, to determine where you need to compensate for non-uniform watering requirements by adding more emitters in hot or less in cool spots.  For example, is the valve irrigating only in the sun, or does it wrap around a building into the shade?

Step 4:  Calculate the number of gallons per day needed by the least-thirsty plant on each valve, to establish that valve's base-line irrigation run time.  For example, if the least-thirsty plant on a valve needs only .25 gallon per day, then two minutes per day (using one emitter) is that valve's base-line. 

Step 5:  Calculate the number of gallons per day needed by the thirstiest plants on each valve, to establish how many more emitters to add for their higher water requirement.  For example, if you add some plants to a valve that need twice as much water as the least-thirsty plants, which are using one emitter, then put two emitters near those thirsty plants.


See Owner's Ops. Manual for additional design criteria.