But you need to adjust BOTH the precip rate AND the sq footage appropriately. You would lower the sq footage to make the system think it’s watering a smaller area, hence using less water, but also calculate and adjust the precip rate to keep the water usage calculated properly. What ever % that you reduce the sq ft by, the same % needs to be added to the flow rate to keep the water calculations correct.
This might be an easier fix:
Crop coefficient (this does NOT affect flex schedules created before 5/19/2016)
Decreasing crop coefficient decreases watering frequency
Available water
Decreasing reduces run time
Root depth
Decreasing reduces run time