1. Water infrequently and deeply: Avoid daily, light watering, this promotes a lawn with shallow root depth and wasted water. Soaking the lawn infrequently with enough water to penetrate the entire root zone will promote grasses with strong, deep root systems. Most established grasses have a root depth of 6 to 8 inches. In general, an established lawn will require 1 to 1.5 inches of water a week, depending on the soil type, to keep the soil in the root zone moist.
2. Water in the early morning (4 to 10 a.m.): Early morning watering is beneficial for several reasons. Watering is more efficient in the morning due to less evaporation and wind speed. Also, the earlier in the morning, the less
likely the system will be competing for water with other appliances in the house like the dish washer, washing machine and shower.
3. Install a rain sensor. A surefire way to drive up your water bill is to operate your irrigation system during a rainstorm. A rain sensor will override the automatic scheduling and shut the system off when enough rain
4. Water only what grows. As landscapes change, it is important to make adjustments to your irrigation system. New installations of benches, decks, shrubs, etc. can obstruct irrigation sprinklers and decrease irrigation efficiency. Also, adjust heads to make sure that water is not hitting the driveway and walkways.
5. Use delayed starts. When watering on a slope, use "delayed starts." For instance, run your sprinklers until you notice runoff, then stop. Wait a couple of hours, then resume watering. This will allow the water time to penetrate
the soil. Aerating your lawn in the spring or fall can also help to increase the infiltration of water.
– John Lahey, owner of Winnipesaukee Irrigation