The heart of an underground system is pop-up sprinkler heads. When working, the heads raise up a few inches to spray water on your landscape. When not in use, they drop to ground level so you can mow or walk right over. That lowers the worry quotient for you, heads off costly over-watering, and makes the whole system almost maintenance-free. An irrigation system divides your property into zones. Examples of zones include:. Everything functions on an automatic timer that controls water flow throughout the. You can elect to include sensors that monitor rain and humidity — self-adjusting timers that prevent unnecessary watering. But planning is a challenge for first-timers. Manufacturers recognize this hurdle and go out of their way to provide planning help. After you give them some info on the size of your lot and your water supply system, they give you an irrigation plan tailored to your property.