An irrigation system is an engineered network designed to distribute precise amounts of water efficiently and automatically across a landscape, supplementing natural rainfall for plants, lawns, or crops. The physical structure varies significantly depending on the application and the specific method of water delivery. Understanding the system involves recognizing the visible and hidden infrastructure that controls the flow, pressure, and timing of the water application.
Essential Components of Pressurized Systems
The foundational elements of any automated irrigation system are largely hidden, forming a complex infrastructure beneath the surface. The system begins at the water source connection, where a device known as a backflow preventer is installed to safeguard the potable water supply. This device is often the most noticeable piece of equipment near the source, appearing as a bulky assembly of brass or plastic pipes and valves mounted above ground to prevent irrigation water from siphoning back into the home’s drinking water.
The entire network is governed by a controller or timer, which serves as the system’s brain, typically mounted on a wall in a garage or utility area. This unit dictates the watering schedule, activating the flow of water through various zones. From the source, the water travels through the mainline, which is a network of buried, pressurized PVC or polyethylene piping designed to transport the bulk water supply.
Water is then routed into distinct watering areas, or zones, controlled by specialized valves. These valves are generally housed inside inconspicuous green or black plastic utility boxes that are flush with the ground. When a zone is activated by the controller, the solenoid in the valve opens to release water into the lateral lines, which carry the flow to the final delivery devices.
The Appearance of Sprinkler and Rotor Systems
Sprinkler systems are the most common type of irrigation seen in residential lawns, designed to cover large turf areas with a spray of water. When inactive, the water-delivering components are mostly concealed, consisting of pop-up spray heads or rotor heads that sit flush with the grass line. The only visible signs of the underlying system are the circular lids of the valve boxes and the tops of these retracted heads.
When the system is active, the difference between the two main head types becomes apparent. Pop-up spray heads are used for smaller, irregularly shaped areas and deliver a continuous, fixed fan of water, often operating at a higher precipitation rate of 1 to 2.5 inches per hour. Rotor heads are used for larger, open spaces and deliver a powerful, single or multiple stream of water that slowly rotates across the landscape.
Rotor heads project water across a greater radius, often from 15 to over 50 feet, while spray heads cover a smaller range, usually 7 to 15 feet. They operate at a lower precipitation rate, typically between 0.5 and 1 inch per hour, which allows the soil more time to absorb the water. During operation, both types extend from their housing, often 4 to 6 inches above the grass, to ensure the spray pattern is unobstructed.
The Appearance of Drip and Micro-Irrigation Systems
Drip and micro-irrigation systems present a stark visual contrast to traditional sprinklers, focusing on targeted, low-volume water delivery. These systems rely on a network of flexible, thick-walled polyethylene tubing, often black, which is snaked directly through planting beds, garden rows, or container groupings. This main tubing is frequently covered by mulch or soil, making the system nearly invisible when properly installed.
The water is delivered through small devices called emitters, which are either pre-installed directly into the tubing or punched in at specific plant locations. Drip emitters release water slowly, usually measured in gallons per hour, allowing it to soak directly into the plant’s root zone in a trickle. This precise application minimizes water loss from evaporation and wind drift.
Micro-irrigation expands on this concept by using small micro-sprayers or micro-sprinklers. These are mounted on short stakes or risers connected to the main tubing via small-diameter, flexible “spaghetti” lines. These micro-devices create a localized mist or spray over a small area, making them suitable for dense groundcover or shrub beds.