A modern lawn sprinkler system is an automated irrigation network designed to deliver precise amounts of water to landscaping on a set schedule. This technology replaces manual watering with programmable, sequential delivery, allowing for efficient water management. Understanding the system involves breaking down the process into stages, from regulating the water source to the final distribution onto the turf. This sequential operation optimizes landscape health.
The System’s Control Center
The operation begins with the controller, often referred to as the system’s brain, which is an electromechanical or electronic device that dictates the entire watering cycle. This unit stores the programmed schedule, including the start times, duration, and days of irrigation for each specific area. When the programmed time arrives, the controller sends a low-voltage electrical current through wires to activate the appropriate water control mechanisms.
Immediately following the connection to the main water supply, the system incorporates a backflow prevention device (BPD), which is a regulatory requirement. The BPD contains internal check valves that ensure water flows only from the potable supply into the irrigation network. This mechanism prevents water that has entered the sprinkler system (which may contain fertilizers or pesticides) from reversing its flow and contaminating the public drinking supply. The device protects against back-siphonage (caused by a pressure drop) and back-pressure (caused by pressure exceeding the supply pressure).
Routing Water Through Zones
The electrical signal sent by the controller travels to a specific solenoid valve, which acts as the gatekeeper for an irrigation zone. Solenoid valves are electromechanical devices that use the received electrical current to open a small internal passageway called a pilot hole. Opening this pilot hole relieves the water pressure that is normally held above a rubber diaphragm inside the valve, allowing the higher pressure water underneath to lift the diaphragm and permit flow.
The system is divided into zones because the available water pressure and flow rate are insufficient to power every sprinkler head simultaneously. Zoning allows the system to manage the flow by isolating sections, ensuring that the necessary water volume and pressure are delivered to one area at a time. Once the solenoid valve opens, pressurized water flows from the main supply line into the underground pipes dedicated to that specific zone, ready for final distribution.
Final Distribution and Output Mechanisms
After passing through the zone valve, the water travels through the main underground pipes and transitions into smaller lateral lines that service the individual sprinkler heads. The type of sprinkler head determines how the water is applied to the landscape, based on the area size and required application rate.
Fixed spray heads are designed for smaller, often irregularly shaped areas, providing a constant, fan-shaped application of water. These heads distribute water simultaneously from all nozzle orifices, covering a radius of 5 to 15 feet. In contrast, rotor heads cover much larger areas, distributing water through a single stream that slowly rotates across the landscape. The rotation is achieved through an internal gear-drive mechanism powered by the flow of water itself.
A third application method involves drip emitters, which are used for non-turf areas like planting beds. These devices apply water very slowly and directly to the soil near the plant’s root zone, maximizing absorption and minimizing evaporation. The choice among these output mechanisms ensures water is applied efficiently across the diverse needs of the landscape.