There is a more efficient way to water that not only wastes less water, but is much better for your plants. Cycle and soak is a method to apply water slowly so the soil absorbs that water deeply, without runoff.
Simply take the total time for each irrigation zone and divide it into multiple cycles. For example, instead of watering a single zone for 15 minutes all at once, set your sprinklers to water that zone three times a day, 5 minutes per zone.
Cycle and soak not only eliminates runoff, it provides more water to the root base. The first cycle will break the surface tension of the soil and allow the water to penetrate. The second cycle will permeate further into the soil, reaching the roots. The third cycle allows the water to seep deeper, creating deeper roots and a healthier plant. Having a third cycle is especially important for sloped areas.
You can simply take the total amount of time scheduled for your irrigation zone and divide it into three cycles, with at least 30 minutes in between. However, to be more efficient, turn on each zone and observe when pooling occurs. This will determine your first time (i.e. 5 minutes.) Repeat this step for each zone. Timing is conditional on plant type, exposure, slope and soil conditions.
Most irrigation controllers can be programmed to cycle and soak.