Paradise Lawn Irrigation System Runtime Calculator

For each station (zone) enter the precipitation rate.  If this is unknown you can estimate spray heads as 1.5-2.0 inches per hour* and rotors as .3-.6 inches per hour*.

 

  Rate in in/hr. 
Enter as a number (ex. .7)		 Uniformity Environment Turf Type
Station 1 Shaded
Full Sun		 Cool Season
Warm Season
Station 2 Shaded
Full Sun		 Cool Season
Warm Season
Station 3 Shaded
Full Sun		 Cool Season
Warm Season
Station 4 Shaded
Full Sun		 Cool Season
Warm Season
Station 5 Shaded
Full Sun		 Cool Season
Warm Season
Station 6 Shaded
Full Sun		 Cool Season
Warm Season
Starts per Week      
Location Above Pearson (cooler)
Below Pearson (warmer)		      
       

* Rainbird 1800 12 head will apply 2.01 inches/hour at 30 psi and 12 foot spacing .   Other popup spray heads are similar.

** Small rotors such a as the Rainbird 42SA may apply at rates as low as 1.8"/hr and Hunter PGJ will apply .30 "/hr in typical full circle configuration.   Pressure, nozzle selection, and spacing will affect the precipitation rate.  

Precipitation Rate
The rate at which water is applied by the irrigation system and commonly expressed in inches per hour.   This can be measured by placing a rain gauge in the lawn and watering for a period of time.   Precipitation rates can vary widely by sprinkler system so measurement is encouraged. 
Uniformity
All irrigation systems apply water in an uneven pattern.   The uniformity is commonly measured as Distribution Uniformity (DU).   Well designed sprinkler systems should have values above 75%.    Lower uniformity will require longer runtimes to insure that the dry areas get adequate water.
Starts per Week
Commonly sprinklers are commonly run multiple times per week.  Lawn watering is more effective in short duration as this reduces runoff and watering of turf below the root zone.   Enter 1 to show the total minutes per week.   If you water Monday, Wednesday, and Friday you would enter 3.